Sample plots were established in the principal forest types in the the Nevado de Toluca National Park, Mexico including those domi- nated by Pinus hartwegii, Abies religiosa, Quercus laurina and Alnus jorullensis. The...Sample plots were established in the principal forest types in the the Nevado de Toluca National Park, Mexico including those domi- nated by Pinus hartwegii, Abies religiosa, Quercus laurina and Alnus jorullensis. The vertical structure was defined by three strata in the coniferous forests and two strata in the broadleaved forests. Timber harvesting in Abies religiosa and Quercus laurina forests and fires generated by humans in Pinus hartwegii forests impeded the recruitment of saplings. Mature trees were also heavily impacted by logging in Pinus hartwegii forests. On the contrary, Alnusjorullensis forests were increas- ing due to the disturbance of Pinus and Quercus forests, as well aban- doned crop lands within the park. A combination of logging, uncon- trolled fire, and grazing appears to be compromising the recruitment of important tree species in this national park. These factors, together with human settlements, have also increased the proportion of early succes- sional species. Changes in forest structure from human disturbance indicate a need to control these activities if conservation goals are not to be compromised.展开更多
Plant species diversity is an important index reflecting the functional complexity and stability of ecosystems.Human activity can completely alter plant species diversity and cause serious degradation of ecosystems bu...Plant species diversity is an important index reflecting the functional complexity and stability of ecosystems.Human activity can completely alter plant species diversity and cause serious degradation of ecosystems but its impact on bamboo forest still lacks of systematic evaluation.In this study,we performed a field investigation to reveal the influences of human disturbances on the plant diversity and stability of Moso bamboo forests at Southern China.The selected bamboo fields contained different intensities of human activities that could be classified as slight,moderate and severe disturbance level.Species richness index S,Shannon-Wienner index H,Simpson index D,Pielou index Jsw,community similarity index IS and community stability index were employed to quantitatively evaluate the plant species diversity and stability.The survey revealed that there were 203 species belonging to 83 families and 108 genera in Moso bamboo forests.The number of plant species in the Moso bamboo forests decreased with the increasing of disturbance intensity.The species diversity indexes generally followed the order of slight>moderate>severe disturbance,as well as the richness index S,Shannon-Wienner index H and Pielou index Jsw.The similarity and species stability of the bamboo forest communities also decreased with the increase of the disturbance intensity.Under the severe disturbance,plant species replacement occurred strongly.The obtained results provide some a guideline for the sustainable management of bamboo forest.展开更多
Moose (Alces alces cameloides) is typically representative of the fauna of the frigid temperate zone and has been put on the Chinese second priority list of protected animals. The moose of northeast China is on the ...Moose (Alces alces cameloides) is typically representative of the fauna of the frigid temperate zone and has been put on the Chinese second priority list of protected animals. The moose of northeast China is on the southern most edge of its distribution in Asia. To study resource selection characteristics of moose and their response to human distur- bances and forest resource variables, the field work was conducted in Heilongiiang Provincial Shengshan Forestry Farm, which is located in the northwestern slope of Lesser Khingan Mountains, northeastern China, from January to March in both 2006 and 2007. A total of 428 plots were examined within the study area. Signs of moose use were found in 19 plots. Based on the analysis of resource selection function, we found that moose selected areas with higher densities of mixed deciduous broadleaf patch and mixed coniferous and broad leaf patch, and a higher NDVI value. Moose avoided settlement 6 km away and remained low probability of occurrence within 3 km from roads,展开更多
From July to September in 2005, the resources of Staphylinidae in four types of human disturbance regions ( human gathering area, grain for green re- gion, grazing region and rare disturbance region) in Erlang Mount...From July to September in 2005, the resources of Staphylinidae in four types of human disturbance regions ( human gathering area, grain for green re- gion, grazing region and rare disturbance region) in Erlang Mountain, Sichuan were investigated, and the individual number, species composition and diversity characteristics were analyzed. The result showed that the individual number, species diversity index (H') and the evenness index (J) decreased with the decrea- sing intensity of human disturbance. The species diversity index and the evenness index in human gathering area were the highest of 4.1301 6 and O. 850 2, respec- tively. Simpson predominant index (A) enhanced with the decreasing intensity of human disturbance, which reached the peak of 0. 199 6 in rare disturbance re- gion. The community similarity index/3 of Staphylinidae at different human disturbance regions ranged from 0 -0.25, indicating that the species compositions were extremely different among this four types of regions. Based on these results, it was found that human activities were closely related to individuals number and species dive^ity of Staphylinidae in Erlang Mountain, and human disturbance may add habitat heterogeneity and facilitate to the species diversity of Staphylinidae communi- ties.展开更多
<span style="font-family:Verdana;">Fiddler crabs are described as ecosystem engineers because of their burrow constructing ability. It was hypothesized that human activity will impact crab burrows. The...<span style="font-family:Verdana;">Fiddler crabs are described as ecosystem engineers because of their burrow constructing ability. It was hypothesized that human activity will impact crab burrows. The study area was delineated into lowly, medium and highly impacted plots. Crab holes were randomly counted and their width, length and surface area estimated. Burrow soils were collected and analyzed for Cadmium (Cd), Lead (Pb) and Zinc (Zn) using spectrophotometric method (HACH DR 890 colorimeter). The result indicates that burrow width was significantly different between impacted plots (P < 0.05). Lowly impacted plot had the largest width while highly impacted plot had the smallest width. In contrast, there was no significant difference in burrow length (P > 0.05), but highly impacted plot has the longest length while lowly impacted plot has the shortest length. Again, the surface area of crab burrow varies significantly (P < 0.05), and lowly impacted plot had the largest area (507.95 ± 61.84 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) followed by medium (390.30 ± 57.65 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) and high (265.16 ± 30.85 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) impacted plots. Similarly, lowly impacted area has more number of burrows (</span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">= 55) followed by medium (</span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">= 30) and highly (</span><i><span style="font-family:Verdana;">n</span></i><span style="font-family:Verdana;"> = 23) impacted plots. Highly impacted plot had the highest Cd and Pb concentration whereas lowly impacted plot had the highest Zn concentration. This implies that burrow morphology and chemistry exemplify the level of anthropogenic impact.</span>展开更多
Aim Due to the important role of lianas in the functioning of forest ecosystem,knowledge of the factors that affect them are important in the management of forests.Currently,there are conflicting reports on the respon...Aim Due to the important role of lianas in the functioning of forest ecosystem,knowledge of the factors that affect them are important in the management of forests.Currently,there are conflicting reports on the response of liana communities to disturbance,calling for more research in the area.The present study was carried out to investigate the response of liana diversity and structure to human disturbance within two major forests in the Penang National Park,Malaysia.The study also looked at the implication of the findings for conservation.Methods A total of 15 40×40-m^(2)(or 40-m×40-m)plots each were randomly located across a range of habitats in a primary forest and disturbed secondary forest.Trees with diameter at breast height≥10 cm were examined for lianas with diameter≥2 cm.Both lianas and trees were enumerated and compared between the two forests.Diversity and structural variables of lianas were compared between the two forests using the t-test analysis.Tree abundance was also compared between the two forests with t-test,while linear regression analysis was run to determine the effects of tree abundance on liana abundance.Important Findings A total of 46 liana species belonging to 27 genera and 15 families were identified in the study.Human disturbance significantly reduced liana species richness and species diversity in the secondary forest.Liana abundance remained the same in both forests whereas liana basal area was;7 times higher in the primary forest.Twiners and hook climbers were significantly more abundant in the primary and secondary forest,respectively.Large diameter lianas were more abundant in the primary forest compared with the secondary forest.The diameter distribution of most families in the primary forest followed the inverted J-shaped curve whereas only a few of the families in the secondary forest did so.Tree abundance was significantly higher in the primary forest.The abundance of lianas significantly depended on tree abundance in all the forests.The study has provided evidence of negative effects of human disturbance on liana diversity and structure that does not auger well for biodiversity in the forest.In view of the critical role of lianas in maintaining biodiversity in the forest ecosystem,lianas in the national park should be protected from further exploitation.展开更多
The four kinds of sites under different kinds of human disturbances,i.e.a farmland area,a rotational-grazing area,an over-grazing area and a prohibited-grazing area,were selected in the typical region of the Alashan D...The four kinds of sites under different kinds of human disturbances,i.e.a farmland area,a rotational-grazing area,an over-grazing area and a prohibited-grazing area,were selected in the typical region of the Alashan Desert of Inner Mongolia from April to October in 2002,2003 and 2004 respectively.The fluctuating tendency of rodent communities and the sensitive response of their populations were studied using mark-recapture and trap-day methods.The four kinds of mark-recapture samples and line samples were taken in different human disturbance areas.The area of the mark-recapturing sample was 0.95 hm2 and that of the line sample was 10 km2.The samples were collected every month in the mark-recapturing sites for four consecutive days and in line sites in April,July and October every year.The variable matrix was composed of the numbers of captured rodents of the rodent communities.The sensitive response of the populations in the communities was analyzed with principal component analysis(PCA).Results showed that there were different types of rodent communities under different kinds of human disturbance on two scales in three years.In each scale,there were large differences in both the number of species and the number of main population in the rodent communities under different kinds of human disturbance on the farmland area and over-grazing area especially.The results of PCA showed that the sensitive response of the populations of the communities was significantly different under different kinds of human disturbance on the two scales in the three years.Cricetulus barabensis was the most sensitive on the farmland area,there were no differences in sensitive response of the various rodents on the rotational-grazing area,and Dipus sagitta and Phodopus roborovskii were the most sensitive in the over-grazing area.展开更多
Understanding the factors that contribute to population stability in long-distance migrant birds is increasingly important, particularly given global climate change, sea level rise, and loss or disturbance at essentia...Understanding the factors that contribute to population stability in long-distance migrant birds is increasingly important, particularly given global climate change, sea level rise, and loss or disturbance at essential habitats. While the populations of most shorebirds are declining worldwide, those that migrate through Delaware Bay, New Jersey and Delaware, are declining at the most rapid rate despite conservation efforts. In this paper, we 1) provide background information on population declines of red knots (Calidris canutus rufa) using Delaware Bay, threats to their foraging, and efforts to reduce threats, 2) summarize briefly our studies of the effects of human activities on knots and other shorebirds, 3) present data on management efforts to protect knots and other shorebirds from the activities of people, and 4) discuss the efficacy of such efforts (usually referred to as “decreasing the effect of human disturbances”). The Shorebird Project on Delaware Bay is over 25 years old and provides long-term data to help assess the status of shorebird numbers, particularly for red knot, as well as the density of horseshoe crabs (Limulus polyphemus) and their eggs. Red knots have continued to decline even more precipitously in the last few years, presenting cause for concern. Protective efforts have been successful in reducing human disruption on the N.J. Delaware Bay beaches, but the lack of uniformity in implementation across the New Jersey side, and across the whole Bay have hampered further improvements. Implementation of signs, fencing, and stewards on some beaches significantly enhanced the use of these beaches by red knots, determined by examining the use of beaches pre- and post-implementation. Implementation of fencing and stewards had the greatest effect. From 1986 to 2018, there was a significant shift in the percent of Delaware Bay red knots using the NJ side, where protection efforts had been implemented on many of the beaches. Merely restricting access (without fencing or other efforts) did not result in more knots using the beaches post-restriction. This is the first paper that clearly shows the protective effects of having beach stewards. We discuss the long-term needs for continued management of Delaware Bay beaches, and other beaches coastwide, and of determining the causes of population declines of red knots.展开更多
Through the statistics and the analysis of landscape map, changes of lands use regime and landscape structure during 20 years were investigated in the agriculture forestry complexed mountain landscape system of Yangd...Through the statistics and the analysis of landscape map, changes of lands use regime and landscape structure during 20 years were investigated in the agriculture forestry complexed mountain landscape system of Yangdong Myon, Yangpyung Gun in the central Korea. Landscape changes of this region was inter related to the recent socio economic development of rural life. Utilization of biomass and other traditional forest management were drastically abandoned in recent 10 years. Landscape analysis of maps showed that the area of secondary vegetation that had been sustained by human nature disturbance was decreased by using of plantation during this time. Those decreased areas were replaced to plantation for wood production and other purpose. Past area of woody species dominated in plantation also substituted to other species. Traditional human activity on secondary vegetation was disappeared. Consequently, the advanced management regimes such as new plantation and cultivation extending areas were increased in abandoned land.展开更多
The changes in soil organic carbon(C) mineralization as affected by anthropogenic disturbance directly determine the role of soils as C source or sink in the global C budget. The objectives of this study were to inves...The changes in soil organic carbon(C) mineralization as affected by anthropogenic disturbance directly determine the role of soils as C source or sink in the global C budget. The objectives of this study were to investigate the effects of anthropogenic disturbance(aquaculture pond, pollutant discharge and agricultural activity) on soil organic C mineralization under different water conditions in the Minjiang River estuary wetland, Southeast China. The results showed that the organic C mineralization in the wetland soils was significantly affected by human disturbance and water conditions(P < 0.001), and the interaction between human disturbance activities and water conditions was also significant(P < 0.01). The C mineralization rate and the cumulative mineralized carbon dioxide-carbon(CO_2-C)(at the 49th day) ranked from highest to lowest as follows: Phragmites australis wetland soil > aquaculture pond sediment > soil near the discharge outlet > rice paddy soil. This indicated that human disturbance inhibited the mineralization of C in soils of the Minjiang River estuary wetland, and the inhibition increased with the intensity of human disturbance. The data for cumulative mineralized CO_2-C showed a good fit(R^2 > 0.91) to the first-order kinetic model C_t = C_0(1 – exp(–kt)). The kinetic parameters C_0, k and C_0 k were significantly affected by human disturbance and water conditions. In addition, the total amount of mineralized C(in 49 d) was positively related to C_0, C_0 k and electrical conductivity of soils. These findings indicated that anthropogenic disturbance suppressed the organic C mineralization potential in subtropical coastal wetland soils, and changes of water pattern as affected by human activities in the future would have a strong influence on C cycling in the subtropical estuarine wetlands.展开更多
The endangered Vatica mangachapoi,a longlived,tropical tree with economic and ecological importance found in Hainan,China,was used to assess the hypothesis that historical human activities in Hainan’s tropical rain f...The endangered Vatica mangachapoi,a longlived,tropical tree with economic and ecological importance found in Hainan,China,was used to assess the hypothesis that historical human activities in Hainan’s tropical rain forest could have negative effects on the genetic diversity of V.mangachapoi.Three hundred and twenty individuals from 11 natural populations—which were classified into three groups according to levels of disturbance—were sampled and analyzed with ISSRmarkers.Although genetic diversity of V.mangachapoi is high at the species level,it is relatively low within populations.A significant genetic differentiation occurs among different disturbance levels.Significant isolation-by-distance indicated relevant historical anthropogenic changes.Our findings showed that historical human disturbances significantly increase the genetic differentiation and slightly decrease the genetic diversity of long-lived tree V.mangachapoi.Relevant targeting conservation actions were recommended.展开更多
Environmental conditions determine woody plant life such as species diversity,structure and regeneration status.This research aimed to assess the impact of environmental conditions on woody plant species diversity,str...Environmental conditions determine woody plant life such as species diversity,structure and regeneration status.This research aimed to assess the impact of environmental conditions on woody plant species diversity,structure and regeneration in forest patches of Guna Mountain:the case of Este District,South Gondar Zone,north-west Ethiopia.A total of 71 square sample plots(400 m~2 each) were established at 10 transects laid in five forest patches of the study area to collect vegetation data including the abundance of species,height and diameter at breast height(DBH).Environmental data including available potassium,available phosphorus,cation exchange capacity,soil texture,electrical conductivity,soil acidity,total nitrogen,organic matter,organic carbon,sodium adsorption ratio,exchangeable sodium percentage,bulk density,aspect,elevation,slope,latitude and longitude data were collected in the same plots.A correlation analysis between vegetation and environmental data was performed using rcorr(x) function in package Hmisc in R Programming Language.The most pronounced impacts were observed in altitude,grazing and pH,positively and silt,sand,electrical conductivity and cation exchange capacity,negatively.In addition,strong and significant impacts on plant structure were also observed due to the variation in soil texture and p H.The difference in aspect,sand and slope also impacted plant regeneration.The study showed that environmental parameters influence the diversity,structure and regeneration of woody plants.These parameters can be considered in the rehabilitation of the vegetation cover and conservation efforts of the rare woody species.Conservation measures that can minimalize the negative influences of environmental conditions can be applied through collaboration with communities around the forest patches.展开更多
Prey animals are often faced with uncertainty due to having imperfect information regarding current local conditions,including predation risks and the availability of reliable foraging opportunities(Dall 2010).As this...Prey animals are often faced with uncertainty due to having imperfect information regarding current local conditions,including predation risks and the availability of reliable foraging opportunities(Dall 2010).As this uncertainty increases,the probability of making costly behavioral errors also increases,leading to more risk averse behavioral tactics(Feyten et al.2019).For example,Trinidadian guppies Poecilia reticulata are far more risk averse when faced with multiple unknown sources of risk assessment information than when faced with a mix of known and unknown cues(Feyten et al.2019).Prey can reduce uncertainty by gathering and integrating private and social information regarding current risk levels within microhabitats(Dall 2010;Munoz and Blumstein 2012).展开更多
Environmental factors affect animal behavior in a variety of ways. Compared to animals in the wild, captive animals are kept in narrow enclosures, suffer higher densities and are more intensely affected by human activ...Environmental factors affect animal behavior in a variety of ways. Compared to animals in the wild, captive animals are kept in narrow enclosures, suffer higher densities and are more intensely affected by human activities. Therefore, behavioral elasticity is likely modified to some extent in captive animals, which may negatively affect the possibility of successful release of endangered species in the wild. In our study we investigated the behaviors of the Oriental White Stork (Ciconia boyciana) in a semi-natural enclosure from 15 October 2005 to 8 September 2006 in Hefei Wildlife Park, China. The behavioral data were collected by instantaneous and scan sampling methods, and we analyzed the relationships between environmental factors and their behaviors. The amounts of time spent on maintenance behavior (foraging and moving) were at similar levels for birds reproducing multibroods (Group 1), birds reproducing one brood (Group 2) and birds without reproduction (Group 3). On the other hand, the amount of time spent on elastic behavior (defensive, breeding and preening) for Group 3 was lower than that for Groups 1 and 2. The behavioral pattern of the storks exhibited marked seasonal changes, which may be a function of ambient temperature, human disturbanc, and the length of daylight, but not of wind intensity. Our results provide basic data for future conser- vation measures of this endangered species.展开更多
We investigated the quantity and quality 0f fallen l0gs in different Tsuga l0ngibracteata f0rest c0mmunities in the Tianba0yan Nati0nal Nature Reserve. We used redundancy analysis t0 determine the spatial distributi0n...We investigated the quantity and quality 0f fallen l0gs in different Tsuga l0ngibracteata f0rest c0mmunities in the Tianba0yan Nati0nal Nature Reserve. We used redundancy analysis t0 determine the spatial distributi0n 0f fallen l0gs in the different f0rest c0mmunities and t0 analyze the relati0nships am0ng stand structure, t0p0graphic fact0rs and human disturbance. The v0lume, c0vered area, mean l0g length and number 0f fallen l0gs differed significantly am0ng f0rest types (P 〈 0.05), but mean diameter at breast height sh0wed n0 significant difference (P 〉 0.05). The l0g v0lume and c0vered area in different f0rest types sh0wed the f0ll0wing trend: T. l0ngibracteata pure f0rest 〈 T. l0ngibracteata + Olig0staehyum scabrifl0rur 〈 T. l0ngibraeteata + hardw00d 〈 Rh0d0dendr0n simiarum + T. l0ngibraeteata 〈 T. l0ngibraeteata + Phyll0stachys heter0cycla pubescens. The spatial distributi0n patterns 0f l0gs quantity and quality indicated that l0g v0lume and c0vered area were str0ngly affected by envir0nmental fact0rs in the f0ll0wing 0rder: human disturbance 〉 elevati0n 〉 sl0pe p0siti0n 〉 b0le height 〉 tree height 〉 sl0pe aspect 〉 density 〉 basal area 〉 sl0pe gradient. The relative c0ntributi0n 0f envir0nmental variables 0n the t0tal variance was t0p0graphy (76%) 〉 disturbance (42%) 〉 stand structure (35%). T0p0graphy and disturbance c0mbined explained 8.2% 0f the variance. Fallen l0~s auantitv and aualitvwere negatively related t0 elevati0n and sl0pe p0siti0n, and p0sitively ass0ciated t0 human disturbance. The l0g v0lume decreased fr0m n0rthern t0 s0uthern sl0pes. Envir0nmental fact0rs had the highest impact 0n class I (slightly decayed), and l0west impact 0n class V (highly decayed).展开更多
Being able to accurately estimate and map forest biomass at large scales is important for a better understanding of the terrestrial carbon cycle and for improving the effectiveness of forest management. In this study,...Being able to accurately estimate and map forest biomass at large scales is important for a better understanding of the terrestrial carbon cycle and for improving the effectiveness of forest management. In this study, forest plot sample data, forest resources inventory(FRI) data, and SPOT Vegetation(SPOT-VGT) normalized difference vegetation index(NDVI) data were used to estimate total forest biomass and spatial distribution of forest biomass in northeast China(with 1 km resolution). Total forest biomass at both county and provincial scales was estimated using FRI data of 11 different forest types obtained by sampling 1156 forest plots, and newly-created volume to biomass conversion models. The biomass density at the county scale and SPOT-VGT NDVI data were used to estimate the spatial distribution of forest biomass. The results suggest that the total forest biomass was 2.4 Pg(1 Pg = 10g), with an average of 77.2 Mg ha, during the study period. Forests having greater biomass density were located in the middle mountain ranges in the study area. Human activities affected forest biomass at different elevations, slopes and aspects. The results suggest that the volume to biomass conversion models that could be developed using more plot samples and more detailed forest type classifications would be better suited for the study area and would provide more accurate biomass estimates. Use of both FRI and remote sensing data allowed the down-scaling of regional forest biomass statistics to forest cover pixels to produce a relatively fineresolution biomass map.展开更多
The aim of this paper is to clarify the pattern and process of changes of landscape in riverside open spaces in urbanized area.The area between the old banks of the Furukawa River in Hiroshima City was examined in thi...The aim of this paper is to clarify the pattern and process of changes of landscape in riverside open spaces in urbanized area.The area between the old banks of the Furukawa River in Hiroshima City was examined in this research.The land use maps of the study area were drawn at seven different times were analyzed,and the number,sizes and perimeters of all patches of all land use types were measured.In these areas,temporal patterns of land use change over the past 30 years were divided to three stages:19661976,19761988 and 19881997.As a result of human disturbance,the riparian forest patches in urbanized areas have decreased in average size and have also become longer and narrower.展开更多
Background: Improved understanding of the processes shaping the assembly of tropical tree communities is crucial for gaining insights into the evolution of forest communities and biological diversity. The climate is t...Background: Improved understanding of the processes shaping the assembly of tropical tree communities is crucial for gaining insights into the evolution of forest communities and biological diversity. The climate is thought to be the first order determinant of abundance and distribution patterns of tree species with contrasting traits such as evergreen and deciduous leaf phenology. However, the relative role of neutral, and niche-based processes in the evolution of these patterns remain poorly understood.Methods: Here, we perform an integrated analysis of the data on tree species abundance, functional traits and community phylogeny from a network of 96 forest plots, each 1 ha in size, distributed along a broad environmental gradient in the central Western Ghats, India. Then, we determine the relative importance of various process in assembly and structuring of tropical forest communities with evergreen and deciduous leaf phenology.Results: The deciduous leaf phenological trait has repeatedly evolved among multiple distantly related lineages. Tree communities in dry deciduous forests were phylogenetically clustered and showed a low range and variance of functional traits related to light harvesting, reproduction, and growth suggesting niche-based processes such as environmental filtering play a vital role in the assembly of tree communities in these forests. The external factors such as human-mediated disturbance also significantly, but to a lesser extent, influences the species and phylogenetic turnover.Conclusions: These findings revealed that the environmental filtering plays a significant role in assembly of tree communities in the biologically diverse tropical forests in the Western Ghats biodiversity hotspot.展开更多
Bird photography is a popular and growing form of ecotourism that contributes to the economic growth of local communities,but its disturbance to bird reproduction remains understudied.We worked in a tropical forest of...Bird photography is a popular and growing form of ecotourism that contributes to the economic growth of local communities,but its disturbance to bird reproduction remains understudied.We worked in a tropical forest of southern China,which has experienced a sharp increase in the number of photographers in recent years.We compared nests that were photographed and those that were not,in their nest predation and parental feeding rates.Including nests of 42 species,the results demonstrate that the predation rate of nests that were not photographed(incubation stage:43.3%of 194 nests;nestling stage:34.5%of 110 nests)was significantly higher than that of photographed ones(incubation:2.4%of 83 nests;nestling:11.1%of 81 nests).Among different nest types,open cup nests in shrub and trees were most affected by photography,in both incubation and nestling stages.Of five factors investigated,including three natural factors(nest stage,structure and position),and two anthropogenic factors(photography and distance to forest edge),only photographic disturbance and nest structure had significant effects(open nests had higher predation).The feeding frequency at nests when photographers were present was not strongly different from when they were not present.Human activity therefore had no negative effects on the birds,but showed a positive effect on their nesting success,in terms of reducing nest predation rates.However,there needs to be further assessment of other aspects of nesting(e.g.,clutch size,duration of nestlings in nests),and other kinds of stress responses(e.g.,hormonal changes),before the total effect of bird photography can be understood.展开更多
Fritillariae Cirrhosae Bulbus is a well-known traditional Chine medicinal herb. However, the demand for this herb is leading to over-collection and its decline in the wild. This study aims to investigate the ecologica...Fritillariae Cirrhosae Bulbus is a well-known traditional Chine medicinal herb. However, the demand for this herb is leading to over-collection and its decline in the wild. This study aims to investigate the ecological conditions of Fritillaria cirrhosa under the influence of human disturbance, biotic species interactions and climatic conditions. We established a total of 78 plots at 14 sites of F. cirrhosa in its distribution center, the Hengduan Mountains area. At each site, we estimated the abundance of F. cirrhosa at different distances from roads. The diameter and height of F. cirrhosa fruit and bulbs were measured and compared to underground bulb depth. We then analyzed the effects of environmental conditions and human disturbance on the abundance of F. cirrhosa using variance partitioning. We found that(1)abundance of F. cirrhosa and their underground bulb depth showed a significant linear increase with the distance from the main road;(2) the diameter/height of fruits and the diameter/height of fruits/bulbs showed significantly different responses to the human disturbance;(3) the community associates,climate and spatial conditions can explain 58%, 22% and 27%, respectively, of the variance in the F. cirrhosa abundance. These results highlight the fact that human disturbance and biotic factors have a great influence on the survival of F. cirrhosa, even more than climate conditions.展开更多
文摘Sample plots were established in the principal forest types in the the Nevado de Toluca National Park, Mexico including those domi- nated by Pinus hartwegii, Abies religiosa, Quercus laurina and Alnus jorullensis. The vertical structure was defined by three strata in the coniferous forests and two strata in the broadleaved forests. Timber harvesting in Abies religiosa and Quercus laurina forests and fires generated by humans in Pinus hartwegii forests impeded the recruitment of saplings. Mature trees were also heavily impacted by logging in Pinus hartwegii forests. On the contrary, Alnusjorullensis forests were increas- ing due to the disturbance of Pinus and Quercus forests, as well aban- doned crop lands within the park. A combination of logging, uncon- trolled fire, and grazing appears to be compromising the recruitment of important tree species in this national park. These factors, together with human settlements, have also increased the proportion of early succes- sional species. Changes in forest structure from human disturbance indicate a need to control these activities if conservation goals are not to be compromised.
基金The present work was financially supported by National Key R&D Program(2018YFD0600104)Scientific Program of Zhejiang Province of China(2017C02016).
文摘Plant species diversity is an important index reflecting the functional complexity and stability of ecosystems.Human activity can completely alter plant species diversity and cause serious degradation of ecosystems but its impact on bamboo forest still lacks of systematic evaluation.In this study,we performed a field investigation to reveal the influences of human disturbances on the plant diversity and stability of Moso bamboo forests at Southern China.The selected bamboo fields contained different intensities of human activities that could be classified as slight,moderate and severe disturbance level.Species richness index S,Shannon-Wienner index H,Simpson index D,Pielou index Jsw,community similarity index IS and community stability index were employed to quantitatively evaluate the plant species diversity and stability.The survey revealed that there were 203 species belonging to 83 families and 108 genera in Moso bamboo forests.The number of plant species in the Moso bamboo forests decreased with the increasing of disturbance intensity.The species diversity indexes generally followed the order of slight>moderate>severe disturbance,as well as the richness index S,Shannon-Wienner index H and Pielou index Jsw.The similarity and species stability of the bamboo forest communities also decreased with the increase of the disturbance intensity.Under the severe disturbance,plant species replacement occurred strongly.The obtained results provide some a guideline for the sustainable management of bamboo forest.
基金financially supported by National Excellent Doctoral Dissertation of PR China-FANEDD(No.201069)""Program for New Century Excellent Talents in University–NCET(No.10-0310)""the Fundamental Research Funds for the Central Universities(No.DL12DA01)
文摘Moose (Alces alces cameloides) is typically representative of the fauna of the frigid temperate zone and has been put on the Chinese second priority list of protected animals. The moose of northeast China is on the southern most edge of its distribution in Asia. To study resource selection characteristics of moose and their response to human distur- bances and forest resource variables, the field work was conducted in Heilongiiang Provincial Shengshan Forestry Farm, which is located in the northwestern slope of Lesser Khingan Mountains, northeastern China, from January to March in both 2006 and 2007. A total of 428 plots were examined within the study area. Signs of moose use were found in 19 plots. Based on the analysis of resource selection function, we found that moose selected areas with higher densities of mixed deciduous broadleaf patch and mixed coniferous and broad leaf patch, and a higher NDVI value. Moose avoided settlement 6 km away and remained low probability of occurrence within 3 km from roads,
基金Supported by Open Fund of Ecological Environmental Research Center in the Chinese Academy of Sciences(SKLURE2011-2-3)Special Fund for Returned Overseas Students in China West Normal University(14B01)Project of HongK ong Ocean Park(HK09)
文摘From July to September in 2005, the resources of Staphylinidae in four types of human disturbance regions ( human gathering area, grain for green re- gion, grazing region and rare disturbance region) in Erlang Mountain, Sichuan were investigated, and the individual number, species composition and diversity characteristics were analyzed. The result showed that the individual number, species diversity index (H') and the evenness index (J) decreased with the decrea- sing intensity of human disturbance. The species diversity index and the evenness index in human gathering area were the highest of 4.1301 6 and O. 850 2, respec- tively. Simpson predominant index (A) enhanced with the decreasing intensity of human disturbance, which reached the peak of 0. 199 6 in rare disturbance re- gion. The community similarity index/3 of Staphylinidae at different human disturbance regions ranged from 0 -0.25, indicating that the species compositions were extremely different among this four types of regions. Based on these results, it was found that human activities were closely related to individuals number and species dive^ity of Staphylinidae in Erlang Mountain, and human disturbance may add habitat heterogeneity and facilitate to the species diversity of Staphylinidae communi- ties.
文摘<span style="font-family:Verdana;">Fiddler crabs are described as ecosystem engineers because of their burrow constructing ability. It was hypothesized that human activity will impact crab burrows. The study area was delineated into lowly, medium and highly impacted plots. Crab holes were randomly counted and their width, length and surface area estimated. Burrow soils were collected and analyzed for Cadmium (Cd), Lead (Pb) and Zinc (Zn) using spectrophotometric method (HACH DR 890 colorimeter). The result indicates that burrow width was significantly different between impacted plots (P < 0.05). Lowly impacted plot had the largest width while highly impacted plot had the smallest width. In contrast, there was no significant difference in burrow length (P > 0.05), but highly impacted plot has the longest length while lowly impacted plot has the shortest length. Again, the surface area of crab burrow varies significantly (P < 0.05), and lowly impacted plot had the largest area (507.95 ± 61.84 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) followed by medium (390.30 ± 57.65 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) and high (265.16 ± 30.85 cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">) impacted plots. Similarly, lowly impacted area has more number of burrows (</span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">= 55) followed by medium (</span><i><span style="font-family:Verdana;">n </span></i><span style="font-family:Verdana;">= 30) and highly (</span><i><span style="font-family:Verdana;">n</span></i><span style="font-family:Verdana;"> = 23) impacted plots. Highly impacted plot had the highest Cd and Pb concentration whereas lowly impacted plot had the highest Zn concentration. This implies that burrow morphology and chemistry exemplify the level of anthropogenic impact.</span>
基金TWAS-USM Postgraduate Fellowship and Research University Grant(RU)(1001/PBIOLOGI/815046).
文摘Aim Due to the important role of lianas in the functioning of forest ecosystem,knowledge of the factors that affect them are important in the management of forests.Currently,there are conflicting reports on the response of liana communities to disturbance,calling for more research in the area.The present study was carried out to investigate the response of liana diversity and structure to human disturbance within two major forests in the Penang National Park,Malaysia.The study also looked at the implication of the findings for conservation.Methods A total of 15 40×40-m^(2)(or 40-m×40-m)plots each were randomly located across a range of habitats in a primary forest and disturbed secondary forest.Trees with diameter at breast height≥10 cm were examined for lianas with diameter≥2 cm.Both lianas and trees were enumerated and compared between the two forests.Diversity and structural variables of lianas were compared between the two forests using the t-test analysis.Tree abundance was also compared between the two forests with t-test,while linear regression analysis was run to determine the effects of tree abundance on liana abundance.Important Findings A total of 46 liana species belonging to 27 genera and 15 families were identified in the study.Human disturbance significantly reduced liana species richness and species diversity in the secondary forest.Liana abundance remained the same in both forests whereas liana basal area was;7 times higher in the primary forest.Twiners and hook climbers were significantly more abundant in the primary and secondary forest,respectively.Large diameter lianas were more abundant in the primary forest compared with the secondary forest.The diameter distribution of most families in the primary forest followed the inverted J-shaped curve whereas only a few of the families in the secondary forest did so.Tree abundance was significantly higher in the primary forest.The abundance of lianas significantly depended on tree abundance in all the forests.The study has provided evidence of negative effects of human disturbance on liana diversity and structure that does not auger well for biodiversity in the forest.In view of the critical role of lianas in maintaining biodiversity in the forest ecosystem,lianas in the national park should be protected from further exploitation.
基金This paper was supported by National Natural Science Foundation of China(Grant No.30160019).
文摘The four kinds of sites under different kinds of human disturbances,i.e.a farmland area,a rotational-grazing area,an over-grazing area and a prohibited-grazing area,were selected in the typical region of the Alashan Desert of Inner Mongolia from April to October in 2002,2003 and 2004 respectively.The fluctuating tendency of rodent communities and the sensitive response of their populations were studied using mark-recapture and trap-day methods.The four kinds of mark-recapture samples and line samples were taken in different human disturbance areas.The area of the mark-recapturing sample was 0.95 hm2 and that of the line sample was 10 km2.The samples were collected every month in the mark-recapturing sites for four consecutive days and in line sites in April,July and October every year.The variable matrix was composed of the numbers of captured rodents of the rodent communities.The sensitive response of the populations in the communities was analyzed with principal component analysis(PCA).Results showed that there were different types of rodent communities under different kinds of human disturbance on two scales in three years.In each scale,there were large differences in both the number of species and the number of main population in the rodent communities under different kinds of human disturbance on the farmland area and over-grazing area especially.The results of PCA showed that the sensitive response of the populations of the communities was significantly different under different kinds of human disturbance on the two scales in the three years.Cricetulus barabensis was the most sensitive on the farmland area,there were no differences in sensitive response of the various rodents on the rotational-grazing area,and Dipus sagitta and Phodopus roborovskii were the most sensitive in the over-grazing area.
文摘Understanding the factors that contribute to population stability in long-distance migrant birds is increasingly important, particularly given global climate change, sea level rise, and loss or disturbance at essential habitats. While the populations of most shorebirds are declining worldwide, those that migrate through Delaware Bay, New Jersey and Delaware, are declining at the most rapid rate despite conservation efforts. In this paper, we 1) provide background information on population declines of red knots (Calidris canutus rufa) using Delaware Bay, threats to their foraging, and efforts to reduce threats, 2) summarize briefly our studies of the effects of human activities on knots and other shorebirds, 3) present data on management efforts to protect knots and other shorebirds from the activities of people, and 4) discuss the efficacy of such efforts (usually referred to as “decreasing the effect of human disturbances”). The Shorebird Project on Delaware Bay is over 25 years old and provides long-term data to help assess the status of shorebird numbers, particularly for red knot, as well as the density of horseshoe crabs (Limulus polyphemus) and their eggs. Red knots have continued to decline even more precipitously in the last few years, presenting cause for concern. Protective efforts have been successful in reducing human disruption on the N.J. Delaware Bay beaches, but the lack of uniformity in implementation across the New Jersey side, and across the whole Bay have hampered further improvements. Implementation of signs, fencing, and stewards on some beaches significantly enhanced the use of these beaches by red knots, determined by examining the use of beaches pre- and post-implementation. Implementation of fencing and stewards had the greatest effect. From 1986 to 2018, there was a significant shift in the percent of Delaware Bay red knots using the NJ side, where protection efforts had been implemented on many of the beaches. Merely restricting access (without fencing or other efforts) did not result in more knots using the beaches post-restriction. This is the first paper that clearly shows the protective effects of having beach stewards. We discuss the long-term needs for continued management of Delaware Bay beaches, and other beaches coastwide, and of determining the causes of population declines of red knots.
文摘Through the statistics and the analysis of landscape map, changes of lands use regime and landscape structure during 20 years were investigated in the agriculture forestry complexed mountain landscape system of Yangdong Myon, Yangpyung Gun in the central Korea. Landscape changes of this region was inter related to the recent socio economic development of rural life. Utilization of biomass and other traditional forest management were drastically abandoned in recent 10 years. Landscape analysis of maps showed that the area of secondary vegetation that had been sustained by human nature disturbance was decreased by using of plantation during this time. Those decreased areas were replaced to plantation for wood production and other purpose. Past area of woody species dominated in plantation also substituted to other species. Traditional human activity on secondary vegetation was disappeared. Consequently, the advanced management regimes such as new plantation and cultivation extending areas were increased in abandoned land.
基金Under the auspices of National Basic Research Program of China(No.2012CB956100)National Natural Science Foundation of China(No.41301085)the Key Foundation of Science and Technology Department of Fujian Province(No.2016R1032-1)
文摘The changes in soil organic carbon(C) mineralization as affected by anthropogenic disturbance directly determine the role of soils as C source or sink in the global C budget. The objectives of this study were to investigate the effects of anthropogenic disturbance(aquaculture pond, pollutant discharge and agricultural activity) on soil organic C mineralization under different water conditions in the Minjiang River estuary wetland, Southeast China. The results showed that the organic C mineralization in the wetland soils was significantly affected by human disturbance and water conditions(P < 0.001), and the interaction between human disturbance activities and water conditions was also significant(P < 0.01). The C mineralization rate and the cumulative mineralized carbon dioxide-carbon(CO_2-C)(at the 49th day) ranked from highest to lowest as follows: Phragmites australis wetland soil > aquaculture pond sediment > soil near the discharge outlet > rice paddy soil. This indicated that human disturbance inhibited the mineralization of C in soils of the Minjiang River estuary wetland, and the inhibition increased with the intensity of human disturbance. The data for cumulative mineralized CO_2-C showed a good fit(R^2 > 0.91) to the first-order kinetic model C_t = C_0(1 – exp(–kt)). The kinetic parameters C_0, k and C_0 k were significantly affected by human disturbance and water conditions. In addition, the total amount of mineralized C(in 49 d) was positively related to C_0, C_0 k and electrical conductivity of soils. These findings indicated that anthropogenic disturbance suppressed the organic C mineralization potential in subtropical coastal wetland soils, and changes of water pattern as affected by human activities in the future would have a strong influence on C cycling in the subtropical estuarine wetlands.
基金partially supported by National Natural Science Foundation of China(31170386,31300403)the Natural Science Foundation of Jiangsu(BK20150503,BK20150504)+4 种基金Jiangsu University Research Foundation for Advanced Talents(14JDG010,15JDG032)the Natural Science Research Project of Higher Education of Jiangsu(14KJB610005)the Jiangsu Planned Projects for Postdoctoral Research Funds(1501028B)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment
文摘The endangered Vatica mangachapoi,a longlived,tropical tree with economic and ecological importance found in Hainan,China,was used to assess the hypothesis that historical human activities in Hainan’s tropical rain forest could have negative effects on the genetic diversity of V.mangachapoi.Three hundred and twenty individuals from 11 natural populations—which were classified into three groups according to levels of disturbance—were sampled and analyzed with ISSRmarkers.Although genetic diversity of V.mangachapoi is high at the species level,it is relatively low within populations.A significant genetic differentiation occurs among different disturbance levels.Significant isolation-by-distance indicated relevant historical anthropogenic changes.Our findings showed that historical human disturbances significantly increase the genetic differentiation and slightly decrease the genetic diversity of long-lived tree V.mangachapoi.Relevant targeting conservation actions were recommended.
基金Addis Ababa UniversityDebre Tabor University,both in Ethiopia,for their sponsorship of the study。
文摘Environmental conditions determine woody plant life such as species diversity,structure and regeneration status.This research aimed to assess the impact of environmental conditions on woody plant species diversity,structure and regeneration in forest patches of Guna Mountain:the case of Este District,South Gondar Zone,north-west Ethiopia.A total of 71 square sample plots(400 m~2 each) were established at 10 transects laid in five forest patches of the study area to collect vegetation data including the abundance of species,height and diameter at breast height(DBH).Environmental data including available potassium,available phosphorus,cation exchange capacity,soil texture,electrical conductivity,soil acidity,total nitrogen,organic matter,organic carbon,sodium adsorption ratio,exchangeable sodium percentage,bulk density,aspect,elevation,slope,latitude and longitude data were collected in the same plots.A correlation analysis between vegetation and environmental data was performed using rcorr(x) function in package Hmisc in R Programming Language.The most pronounced impacts were observed in altitude,grazing and pH,positively and silt,sand,electrical conductivity and cation exchange capacity,negatively.In addition,strong and significant impacts on plant structure were also observed due to the variation in soil texture and p H.The difference in aspect,sand and slope also impacted plant regeneration.The study showed that environmental parameters influence the diversity,structure and regeneration of woody plants.These parameters can be considered in the rehabilitation of the vegetation cover and conservation efforts of the rare woody species.Conservation measures that can minimalize the negative influences of environmental conditions can be applied through collaboration with communities around the forest patches.
基金supported by the Natural Sciences and Engineering Research Council of Canada Discovery Grants program and Concordia University to G.E.B.
文摘Prey animals are often faced with uncertainty due to having imperfect information regarding current local conditions,including predation risks and the availability of reliable foraging opportunities(Dall 2010).As this uncertainty increases,the probability of making costly behavioral errors also increases,leading to more risk averse behavioral tactics(Feyten et al.2019).For example,Trinidadian guppies Poecilia reticulata are far more risk averse when faced with multiple unknown sources of risk assessment information than when faced with a mix of known and unknown cues(Feyten et al.2019).Prey can reduce uncertainty by gathering and integrating private and social information regarding current risk levels within microhabitats(Dall 2010;Munoz and Blumstein 2012).
基金supported by the National Natural Science Foundation of China (Grant No. 3087317, 30470257)the Anhui Academic and Technical Leaders Fund
文摘Environmental factors affect animal behavior in a variety of ways. Compared to animals in the wild, captive animals are kept in narrow enclosures, suffer higher densities and are more intensely affected by human activities. Therefore, behavioral elasticity is likely modified to some extent in captive animals, which may negatively affect the possibility of successful release of endangered species in the wild. In our study we investigated the behaviors of the Oriental White Stork (Ciconia boyciana) in a semi-natural enclosure from 15 October 2005 to 8 September 2006 in Hefei Wildlife Park, China. The behavioral data were collected by instantaneous and scan sampling methods, and we analyzed the relationships between environmental factors and their behaviors. The amounts of time spent on maintenance behavior (foraging and moving) were at similar levels for birds reproducing multibroods (Group 1), birds reproducing one brood (Group 2) and birds without reproduction (Group 3). On the other hand, the amount of time spent on elastic behavior (defensive, breeding and preening) for Group 3 was lower than that for Groups 1 and 2. The behavioral pattern of the storks exhibited marked seasonal changes, which may be a function of ambient temperature, human disturbanc, and the length of daylight, but not of wind intensity. Our results provide basic data for future conser- vation measures of this endangered species.
基金supported by the National Natural Science Foundation of China (Grant No.31370624)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20103515110005)the Natural Science Foundation of Fujian, China (Grant No. 2011J01071)
文摘We investigated the quantity and quality 0f fallen l0gs in different Tsuga l0ngibracteata f0rest c0mmunities in the Tianba0yan Nati0nal Nature Reserve. We used redundancy analysis t0 determine the spatial distributi0n 0f fallen l0gs in the different f0rest c0mmunities and t0 analyze the relati0nships am0ng stand structure, t0p0graphic fact0rs and human disturbance. The v0lume, c0vered area, mean l0g length and number 0f fallen l0gs differed significantly am0ng f0rest types (P 〈 0.05), but mean diameter at breast height sh0wed n0 significant difference (P 〉 0.05). The l0g v0lume and c0vered area in different f0rest types sh0wed the f0ll0wing trend: T. l0ngibracteata pure f0rest 〈 T. l0ngibracteata + Olig0staehyum scabrifl0rur 〈 T. l0ngibraeteata + hardw00d 〈 Rh0d0dendr0n simiarum + T. l0ngibraeteata 〈 T. l0ngibraeteata + Phyll0stachys heter0cycla pubescens. The spatial distributi0n patterns 0f l0gs quantity and quality indicated that l0g v0lume and c0vered area were str0ngly affected by envir0nmental fact0rs in the f0ll0wing 0rder: human disturbance 〉 elevati0n 〉 sl0pe p0siti0n 〉 b0le height 〉 tree height 〉 sl0pe aspect 〉 density 〉 basal area 〉 sl0pe gradient. The relative c0ntributi0n 0f envir0nmental variables 0n the t0tal variance was t0p0graphy (76%) 〉 disturbance (42%) 〉 stand structure (35%). T0p0graphy and disturbance c0mbined explained 8.2% 0f the variance. Fallen l0~s auantitv and aualitvwere negatively related t0 elevati0n and sl0pe p0siti0n, and p0sitively ass0ciated t0 human disturbance. The l0g v0lume decreased fr0m n0rthern t0 s0uthern sl0pes. Envir0nmental fact0rs had the highest impact 0n class I (slightly decayed), and l0west impact 0n class V (highly decayed).
基金supported by the National Natural Science Foundation of China(No.41401500)the National Key Technologies R&D Program of China(2012BAD22B04)+5 种基金the China Postdoctoral Science Foundation(2015M580629,2016M590679)the Key Scientific Research Projects of Higher Education of Henan Province,China(16A420003,17A420001)Scientific and Technological Innovation Team of Universities in Henan Province,China(18IRTSTHN008)Funds for Fundamental Scientific Research in Colleges in Henan Province,China(NSFRF1630)Innovation Research Team of Henan Polytechnic University,China(B2017-16)the China Coal Industry Association Guidance Program(MTKJ-2015-285)
文摘Being able to accurately estimate and map forest biomass at large scales is important for a better understanding of the terrestrial carbon cycle and for improving the effectiveness of forest management. In this study, forest plot sample data, forest resources inventory(FRI) data, and SPOT Vegetation(SPOT-VGT) normalized difference vegetation index(NDVI) data were used to estimate total forest biomass and spatial distribution of forest biomass in northeast China(with 1 km resolution). Total forest biomass at both county and provincial scales was estimated using FRI data of 11 different forest types obtained by sampling 1156 forest plots, and newly-created volume to biomass conversion models. The biomass density at the county scale and SPOT-VGT NDVI data were used to estimate the spatial distribution of forest biomass. The results suggest that the total forest biomass was 2.4 Pg(1 Pg = 10g), with an average of 77.2 Mg ha, during the study period. Forests having greater biomass density were located in the middle mountain ranges in the study area. Human activities affected forest biomass at different elevations, slopes and aspects. The results suggest that the volume to biomass conversion models that could be developed using more plot samples and more detailed forest type classifications would be better suited for the study area and would provide more accurate biomass estimates. Use of both FRI and remote sensing data allowed the down-scaling of regional forest biomass statistics to forest cover pixels to produce a relatively fineresolution biomass map.
文摘The aim of this paper is to clarify the pattern and process of changes of landscape in riverside open spaces in urbanized area.The area between the old banks of the Furukawa River in Hiroshima City was examined in this research.The land use maps of the study area were drawn at seven different times were analyzed,and the number,sizes and perimeters of all patches of all land use types were measured.In these areas,temporal patterns of land use change over the past 30 years were divided to three stages:19661976,19761988 and 19881997.As a result of human disturbance,the riparian forest patches in urbanized areas have decreased in average size and have also become longer and narrower.
基金supported by the following:NSERC-Canada grant to SD,SKN received scholarship from Concordia University,Canada and International Internship from Fonds Nature et technologies(FQRNT)which is gratefully
文摘Background: Improved understanding of the processes shaping the assembly of tropical tree communities is crucial for gaining insights into the evolution of forest communities and biological diversity. The climate is thought to be the first order determinant of abundance and distribution patterns of tree species with contrasting traits such as evergreen and deciduous leaf phenology. However, the relative role of neutral, and niche-based processes in the evolution of these patterns remain poorly understood.Methods: Here, we perform an integrated analysis of the data on tree species abundance, functional traits and community phylogeny from a network of 96 forest plots, each 1 ha in size, distributed along a broad environmental gradient in the central Western Ghats, India. Then, we determine the relative importance of various process in assembly and structuring of tropical forest communities with evergreen and deciduous leaf phenology.Results: The deciduous leaf phenological trait has repeatedly evolved among multiple distantly related lineages. Tree communities in dry deciduous forests were phylogenetically clustered and showed a low range and variance of functional traits related to light harvesting, reproduction, and growth suggesting niche-based processes such as environmental filtering play a vital role in the assembly of tree communities in these forests. The external factors such as human-mediated disturbance also significantly, but to a lesser extent, influences the species and phylogenetic turnover.Conclusions: These findings revealed that the environmental filtering plays a significant role in assembly of tree communities in the biologically diverse tropical forests in the Western Ghats biodiversity hotspot.
基金supported by the National Natural Science Foundation of China(Grant No.31870370)the Graduate Education Innovation Program of Guangxi(No.YCSW2020023)。
文摘Bird photography is a popular and growing form of ecotourism that contributes to the economic growth of local communities,but its disturbance to bird reproduction remains understudied.We worked in a tropical forest of southern China,which has experienced a sharp increase in the number of photographers in recent years.We compared nests that were photographed and those that were not,in their nest predation and parental feeding rates.Including nests of 42 species,the results demonstrate that the predation rate of nests that were not photographed(incubation stage:43.3%of 194 nests;nestling stage:34.5%of 110 nests)was significantly higher than that of photographed ones(incubation:2.4%of 83 nests;nestling:11.1%of 81 nests).Among different nest types,open cup nests in shrub and trees were most affected by photography,in both incubation and nestling stages.Of five factors investigated,including three natural factors(nest stage,structure and position),and two anthropogenic factors(photography and distance to forest edge),only photographic disturbance and nest structure had significant effects(open nests had higher predation).The feeding frequency at nests when photographers were present was not strongly different from when they were not present.Human activity therefore had no negative effects on the birds,but showed a positive effect on their nesting success,in terms of reducing nest predation rates.However,there needs to be further assessment of other aspects of nesting(e.g.,clutch size,duration of nestlings in nests),and other kinds of stress responses(e.g.,hormonal changes),before the total effect of bird photography can be understood.
基金supported by Yunnan Environmental Protection Special Fund 2013, Grant No. 214203the National Natural Science Foundation of China (NSFC) Grant No. 31560063Key Disciplines (Ecology) Project of Yunnan Education Department
文摘Fritillariae Cirrhosae Bulbus is a well-known traditional Chine medicinal herb. However, the demand for this herb is leading to over-collection and its decline in the wild. This study aims to investigate the ecological conditions of Fritillaria cirrhosa under the influence of human disturbance, biotic species interactions and climatic conditions. We established a total of 78 plots at 14 sites of F. cirrhosa in its distribution center, the Hengduan Mountains area. At each site, we estimated the abundance of F. cirrhosa at different distances from roads. The diameter and height of F. cirrhosa fruit and bulbs were measured and compared to underground bulb depth. We then analyzed the effects of environmental conditions and human disturbance on the abundance of F. cirrhosa using variance partitioning. We found that(1)abundance of F. cirrhosa and their underground bulb depth showed a significant linear increase with the distance from the main road;(2) the diameter/height of fruits and the diameter/height of fruits/bulbs showed significantly different responses to the human disturbance;(3) the community associates,climate and spatial conditions can explain 58%, 22% and 27%, respectively, of the variance in the F. cirrhosa abundance. These results highlight the fact that human disturbance and biotic factors have a great influence on the survival of F. cirrhosa, even more than climate conditions.