Species spatial distributions in a warm-temperate deciduous broad-leaved forest in China

Spatial distribution is fundamental for understanding species coexistence mechanisms in forest communities.Here we comprehensively explored fine-scale spatial patterns of tree species in a secondary warm-temperate deciduous broad-leaved forest community in north China.Aggregated distribution patterns were predominant.Species functional traits had no significant effects on their spatial patterns.The aggregation intensity decreased with increasing DBH and abundance.The multivariate linear stepwise regression showed that abundance and maximum DBH were correlated with the aggregation intensity.Our results partially confirm that species attributes(abundance,DBH)and habitat heterogeneity may primarily contribute to spatial patterns and species coexistence in this secondary forest.

Effects of simulated acid rain on seedling emergence and growth of five broad-leaved species

Seeds and seedlings of five broad-leaved species were separately exposed to simulated acid rain at pH values of 2.0, 3.5, 5.0, and 6.0, or to distilled water (the control). The results showed that seed germination was remarkably inhibited by pH 2.0 treatment for three species. Significant foliar damage, decline in chlorophyll contents, and retardation of the seedlings growth of all the species, were observed at pH 2.0 treatment. The pH 2.0 treatment seemed to be a threshold level for inhibition of seed germination and seedling growth for all the treated species, while seedling was stimulated at pH value between 3.5 and 5.0.

The rapid climate change-caused dichotomy on subtropical evergreen broad-leaved forest in Yunnan： Reduction in habitat diversity and increase in species diversity

Yunnan's biodiversity is under considerable pressure and subtropical evergreen broad-leaved forests in this area have become increasingly fragmented through agriculture,logging,planting of economic plants,mining activities and changing environment.The aims of the study are to investigate climate changeinduced changes of subtropical evergreen broad-leaved forests in Yunnan and identify areas of current species richness centers for conservation preparation.Stacked species distribution models were created to generate ensemble forecasting of species distributions,alpha diversity and beta diversity for Yunnan's subtropical evergreen broad-leaved forests in both current and future climate scenarios.Under stacked species distribution models in rapid climate changes scenarios,changes of water-energy dynamics may possibly reduce beta diversity and increase alpha diversity.This point provides insight for future conservation of evergreen broad-leaved forest in Yunnan,highlighting the need to fully consider the problem of vegetation homogenization caused by transformation of water-energy dynamics.

Change in Species Diversity during Recovering Process of Evergreen Broad-leaved Forest

Evergreen broad-leaved forestis one of the most important vegetation types in China.Because of the human activities,evergreen broad-leaved forest has been destroyed extensively,leading to degraded ecosystem.It is urgent to conserve and restore these natural forests in China. In this paper,the tendency and rate of species diversity restoration of the evergreen broad-leaved forest in Daming Mountain has been studied.The main resultsare as follows:(a)In subtropical mid-mountain area,species diversity in degraded evergreen broad-leaved forestcan be restored. Through analyzing b diversity index of communities in different time and space,it was found that the species composition of communities tend to be the same as that in the zonal evergreen broad-leaved forest.(b)The restoration rate of evergreen broad-leaved forest was very fast.Planting Chinese fir after clear-cutting and controlled burning of the forest,178 species appeared in a 600m^2 sample area after 20 years’natural recovering.Among the sespecies,58 were tree layer and the height of community reached 18m.The survey suggested that it would take only 20 years for the degraded forest to develop into community composed of lightdemanding broad-leaved pioneer trees and min-tolerance broad-leaved trees,and it need another 40~80 years to reach the stage consisting of min-tolerance evergreen broad-leaved trees.(c)Species number increased quickly at the early stage(2-20years)during vegetation recovering process toward the climax,and decreased at the min-stage (50-60 years),then maintained a relatively stable level at the late-stage (over 150 years).

Recovery of species diversity after disturbance of broad-leaved Korean pine mixed forest in Changbai Mountain

Recovery of species diversity after catastrophic disturbance was influenced by a few factors, such as intensity of disturbance, availability of propagules, and the environmental conditions, In this paper, we examined pattems of species development after nearly 60a succession in bumed broad-leaved Korean pine mixed forest on northem slope of ChangbaiMountain. We aasessed the recovery of plant species diversity in 3 types of forests under the contition with gradient of soil moisture. Results revealed that recovery of plant species (liversity varied greatly under different environmental conditions.Species richness of secondary forests greatly related to the site condition. Secondary birch forest on mesic site had the greatest number of plant species and the following was poplar-birch forest and larch-birch forest.Most of characteristic taxa couldbe found in birch forest after 60a succession. For larch-birch forest on hydra site, most of climax species were still not able to invade, so it had the lowest species diversity.

The influence of selective cutting of mixed Korean pine(Pinus koraiensis Sieb.et Zucc.) and broad-leaf forest on rare species distribution patterns and spatial correlation in Northeast China

This study aimed to demonstrate change in spatial correlation between Korean pine （Pinus koraiensis Sieb. et Zucc.） and three rare species, and change in spatial distribution of four species in response to a range of selective cutting intensities. We sampled three plots of mixed Korean pine and broad-leaf forest in Lushuihe Forestry Bureau of Jilin province, China. Plot 1, a control, was unlogged Korean pine broad-leaf forest. In plots 2 and 3, Korean pine was selectively cut at 15 and 30 % intensity, respectively, in the 1970s. Other species were rarely cut. We used point-pattern analysis to research the spatial distributions of four tree species and quantify spatial correlations between Korean pine and the other three species, Amur linden （Tilia amurensis Rupr.）, Manchurian ash （Fraxinus mandshurica Rupr.）, and Mongolian oak （Quercus mongolica Fisch.） in all three plots. The results of the study show that selective cutting at 15 % intensity did not significantly change either the species spatial patterns or the spatial correlation between Korean pine and broadleaf species. Selective cutting at 30 % intensity slightly affected the growth of Korean pine and valuable species in forest communities, and the effect was considered nondestructive and recoverable.

Biology of Flowering of Some Species of the Genus Phlomoides Moench

The article presents the biology of flowering and the daily dynamics of flowering of two species from the Lamiaceae family: ph. anisochila va ph. sogdiana of the distribution out in the Nuratau Mountains range.

Plants Diversity of the Burigi-Chato National Park: Rare and Invasive Species

This study was conducted within a distance of three to five kilometres around Lake Burigi as a study area in the Burigi-Chato National Park for the purpose of documenting the diversity of plants, identifying invasive and rare species for enhancing conservation in the park. Lake Burigi was purposively sampled as a study area for plant identification due to its potential as a tourist destination. No study has been conducted in the study area to reveal plants diversity, with a focus on documenting invasive and rare species, thus necessitating undertaking of this study to inform the park authority to take urgent control measures in avoiding widespread of invasive species and proper planning for conservation of rare species. The methods involved included field observation;plant identification using field guide books, indigenous and professional knowledge;field mapping using GPS receiver and literature review. Analysis of meteorological data and soil sample were also used among other methods. Meteorological data were analysed using Microsoft Excel and SPSS v.20 to determine the relationship between variables. A total of 102 plant species of different growth forms of trees, shrubs, grasses, sedges, forbs, and herbs were identified and recorded. Tegetes minuta and Argemone mexicana were recorded as invasive plant species, while six rare plant species potential for pharmaceutical industry;Zanthoxylum usambarense, Gardenia ternifolia, Faidherbia albida, Harrisonia abyssinica, Anona senegalensis, and, Pappea capensis were also recorded. Scars of wildfires were observed in the study area. The study area received an average rainfall of 964.36 mm per year, the highest peak recorded in 1951. The trend of rainfall showed that many years had rainfall below the average while the temperature was found to increase from year to year, the situation which suggests the existence of climate change in the study area. There was a weak negative relationship between temperature and wind speed. Soil nutrients and disturbances in the area were found to favour the growth of Tegetes minuta. Findings of this study would help ecological unit in the park to conduct regular ecological assessment for the purpose of controlling invasive plant species, which if left to flourish are likely to reduce habitat suitability for ungulates to utilize the area. Moreover, knowing which plant species are rare, adds value to the area as a destination to visitors interested in plants. The findings also allow the park authority to keep record of species rarity and thus easily take control of them to avoid unintended exploitation. Based on the findings, it was concluded that a number of disturbances, meteorological and edaphic factors favour the growth of invasive species. Urgent measures are to be taken to control the observed invasive plant species before they are left to spread in the park to avoid destruction of the habitat suitability and incurring unnecessary expenses and time in combating them. Furthermore, rare plant species especially those with pharmaceutical and industrial values are to be conserved with special attention to ensure their continued survival. It was recommended that human-induced activities should be prevented through regular ecological assessment, field patrols and public awareness programs. A similar study needs to be conducted during dry season to make comparison of the capacity of plants in adapting to different changes of the weather.

A Study on Photosynthetic Physiological Characteristics of Six Rare and Endangered Species

The parameters of gas exchange and chlorophyl fluorescence in leaves of six rare and endangered species Neolitsea sericea, Cinnamomum japonicum var. cheni , Sinojackia microcarpa, Discocleidion glabrum var. trichocarpum, Parrotia sub-aequalis, Cercidiphyl um japonicum were measured in fields. The results showed that there were significant differences in photosynthetic capacity, intrinsic water use effi-ciency （WUEi ）, the efficiency of primary conversion of light energy of PSⅡ and its potential activity, the quantum yield of PSⅡ electron transport, and the potential ca-pacity of heat dissipation among the six species. However, there was no significant difference in WUE. The highest values of net photosynthetic rate （Pn）, transpiration rate （Tr） and stomatal conductance （gs） occurred in D. glabrum var. trichocarpum and the lowest in S. microcarpa. On the contrary, D. glabrum var. trichocarpum had the lowest WUE, intrinsic water use efficiency （WUEi ） and S. microcarpa had the highest. The results indicated that D. glabrum var. trichocarpum had higher photo-synthetic capacity and poorer WUE, while S. microcarpa had lower photosynthetic capacity and greater WUE. Furthermore, the mean values of maximal fluorescence （Fm）, potential efficiency of primary conversion of light energy of PSⅡ （Fv/Fm）,ΦPSⅡ, actual efficiency of primary conversion of light energy of PSⅡ （F′v/F′m） and non-photochemical quenching coefficient （NPQ） were the highest in S. micro-carpa, indicating that its PSⅡ had higher capacity of heat dissipation and could prevent photosynthetic apparatus from damage by excessive light energy. Correlation analysis showed that there were significant correlations among photosynthetic physi-ological parameters. However, the initial fluorescence （Fo） was not significantly cor-related with any other parameters. This study also revealed the extremely significant positive correlations between Pn and Tr, gs, apparent quantum yield （AQY）, be-tween Tr and gs, between light saturation point （LSP） and AQY, between Fv/Fm and Fm, between ΦPSⅡ and photochemical quenching coefficient （qp）, between Tr, gs and LSP, AQY. However, WUEi was significantly negatively correlated with Tr, gs, Pn, LSP and AQY.

Forest structure,productivity and soil properties in a subtropical ever-green broad-leaved forest in Okinawa,Japan

Structure, species composition, and soil properties of a subtropical evergreen broad-leaved forest in Okinawa, Japan, were examined by establishment of plots at thirty sites. The forest was characterized by a relatively low canopy and a large number of small-diameter trees. Mean canopy height for this forest was 10 m and stands contained an average of 5400 stems-ha^-1 （ -〉 3.0 cm DBH）; 64% of those stems were smaller than 10 cm DBH. The total basal area was 54.4 m^2-ha^-1, of which Castanopsis sieboldii contributed 48%. The forest showed high species diversity of trees. 80 tree species （≥ 3.0 cm DBH） from 31 families was identified in the thirty sampling plots. C. sieboldii and Schima wallichii were the dominant and subdominant species in terms of importance value. The mean tree species diversity indices for the plots were, 3.36 for Diversity index （H＇）, 0.71 for Equitability index （J＇） and 4.72 for Species richness index （S＇）, all of which strongly declined with the increase of importance value of the dominant, C. sieboldii. Measures of soil nutrients indicated low fertility, extreme heterogeneity and possible A1 toxicity. Regression analysis showed that stem density and the dominant tree height were significantly correlated with soil pH. There was a significant positive relationship between species diversity index and soil exchangeable K^＋, Ca^2＋, and Ca^2＋/Al^3- ratio （all p values 〈0.001） and a negative relationship with N, C and P. The results suggest that soil property is a major factor influencing forest composition and structure within the subtropical forest in Okinawa.

Decomposition patterns of leaf litter of seven common canopy species in a subtropical forest： dynamics of mineral nutrients

Dynamical patterns of mineral elements during decomposition processes were investigated for seven common canopy species in a subtropical evergreen broad-leaved forest by means of litterbag technique over 2 years. The species studied are representative for the vegetation in the study area and differed significantly in chemical qualities of their litter. No significant relationships were found between decomposition rate （percentage dry mass remaining and decomposition constant k） and initial element cuncentrations.However, there were significant correlations betweeu the percentage of dry mass remaining and the mineral element concentrations in the remaining litter for most cases. The rank of the element mobility in decomposition process was as follows： Na = K 〉 Mg ≥ Ca 〉 N ≥ Mn ≥ Zn ≥ P 〉 Cu 〉〉 Al 〉〉 Fe. Concentrations of K and Na decreased in all species as decomposition proceeded. Calcium and Mg also decreased in concentrntion but with a temporal increase in the initial phase of decomposition, while the concentrations of other elements （Zn, Cu, AL and Fei increased for all species with exception of Mn which revealed a different pattern in different species. In most species, microelements （Cu, Al, and Fe） significantly increased in absolute amounts at the end of the litterbag incubation, which could be ascribed to a lange extent to the mechanism of abiotic fixation to humic substances rather than biological immobilization.

Combined community ecology and floristics,a synthetic study on the upper montane evergreen broad-leaved forests in Yunnan,southwestern China

The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous,island-like,distribution.It is diverse,rich in endemic species,and likely to be sensitive to climate change.Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan.All trees with d.b.h.>1 cm in each plot were identified.Patterns of seed plant distributions were quantified at the specific,generic and family levels.The forests are dominated by the families Fagaceae,Lauraceae,Theaceae and Magnoliaceae,but are very diverse with only a few species shared between sites.Floristic similarities at the family and generic level were high,but they were low at the specific level,with species complementarity between plots.Diversity varied greatly among sites,with greater species richness and more rare species in western Yunnan than central Yunnan.The flora is dominated by tropical biogeographical elements,mainly the pantropic and the tropical Asian distributions at the family and genus levels.In contrast,at the species level,the flora is dominated by the southwest or the southeast China distributions,including Yunnan endemics.This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin,and has adapted to cooler temperatures with the uplift of the Himalayas.Due to great sensitivity to climate,high endemism and species complementarity,as well as the discontinuous,island-like,distribution patterns of the upper montane forest in Yunnan,the regional conservation of the forest is especially needed.

Accumulation of Lathenum with Various Species in Oryzias Latipes Body

The accumulation and absorption kinetics of La by fish (Oryzias latipes) from both water and food were tested in fresh water. The effects of La concentration in water and food and the existence of fulvic acid on the absorption were investigated. It was demonstrated that the amount of La accumulated in fish increases with the increase in La concentration in water and food and exposure duration, which the normal physiological activity of fish was inhibited. With fulvic in the system, the absorption rate decreases significantly indicating that the fulvic combined La is not available to the fish uptake.

Canopy arthropods community within and among oak species in central Mexico

Quercus rugosa and Q.laurina are species that presents a wide geographical distribution range in temperate forests of Mexico. Oak canopies contain a considerable portion of arthropod diversity and the arthropods fauna fulfill a wide variety of ecological roles. We examined the effect of oak species and seasonal changes on some community structure parameters (diversity,composition,similarity,biomass,rare species,and density of arthropod fauna) of canopy arthropods. In total,40 oak canopies were fogged during rainy and dry season. A total of 614 identified arthropod morphospecies were recognized belonging to 22 orders associated with tree canopies. A separation of host tree species during both seasons,suggesting a different community structure on host plants species was demonstrated by the principal component analyses (PCA),therefore,differences between oak species results in phenotypes that structure the composition of the arthropod community. Q.laurina registered the highest densities,diversity index and number of rare species in comparison with Q.rugosa. While arthropod biomass showed an inverse pattern. Trees more close to one another (spatial distance) register a more similar canopy arthropod fauna. This study suggests that the trees of Q.laurina could act as a center of biodiversity by the accumulation of arthropod fauna with a considerable number of rare species,which presents wide ecological roles or is involved in critical processes that maintain forest ecosystems.

Morphological Variation in the Martinican Subspecies White-Breasted Thrasher (<i>Ramphocinclus brachyurus brachyurus</i>)

The White-breasted Thrasher (Ramphocinclus brachyurus) is the smallest passerine bird in the Mimids family. Ranked as “endangered” in the IUCN list, the demographic distribution of this species is spread unevenly across two islands in the Lesser Antilles. The Saint-Lucian subspecies, Ramphocinclus brachyurus sanctaeluciae, was estimated to number between 1200 and 1700 individuals, whereas the Martinique subspecies, Ramphocinclus brachyurus brachyurus, was estimated at between 200 and 400 individuals. As an endemic rare species with a high risk of extinction, the Martinique subspecies should be regarded as a conservation priority. The small size of the Martinique subspecies population, its restricted geographical range, and its narrow habitat tolerance make it quite difficult to study. The variability of morphological traits in this subspecies has not been biostatistically analyzed recently. In order to update knowledge and fill in any gaps, we have used the morphometric approach to study the morphological variability of the Martinique subspecies. The study site is a small peninsula located in the northeast of the island of Martinique (French West Indies) known as “la Caravelle”. We captured 63 White-breasted Thrashers which were marked, measured, and sexed before being released. We did not observe any significant differences between the sexes, signifying an absence of sexual dimorphism. However, we were able to observe a significant variation in morphological traits between individuals measured inside and outside the national protected area of Caravelle. The body mass-tarsus ratio was equal at both sampled sites, something which could potentially be a clue to the bird’s adaptation to different habitats.

Population dynamics and considerations for the conservation of the rare Cycas fairylakea in China

Quantitative dynamics and viability of a rare and wild Cycas fairylakea population were studied with a time-specific life table, a Leslie matrix model and a survival function in order to provide scientific guidance for its protection. The results of the time- specific life table show that this C. fairylakea population suffered a high death rate in three age classes, i.e., age class 1 （0-15 years）, V （61-75 years） and VI （76-90 years）. The Leslie matrix model suggests that the number of plants would decline from the present 1613 to 59 per hectare in 150 years. Furthermore, the viability analysis indicates that seedlings have the highest mortality density rate and that middle-aged plants （i.e., 61-75 years, 76-90 years） have high mortality density rate and hazard rate. These conditions affect natural regeneration of the population and lead to a lack of seedlings which in turn causes the extinction of the population. An in situ conservation of the population should be established and protection measures taken as soon as possible.

Study on successions sequence of evergreen broad-leaved forest in Gutian Mountain of Zhejiang,Eastern China:species diversity

Using the widely adopted scheme of space-for-time substitution for investigating 16 typical plots distri-buted as a pattern of contiguous grid quadrates within a sampling plot,the expressions of Shannon-Wiener index(H)for species diversity,Pielou index(J_(sw),J_(SI))for evenness and Simpson index(D)for ecological dominance are employed to investigate the species diversity(SD)of four evergreen broadleaved communities in the successions sequence within the Nature Reserve of the Gutian Mountains.Results showed that in the successions process from the coniferous to the mixed coniferous-broadleaved,then to Schima superba and finally to Castanopsis eyrei forest,the arbor layer SD showed the Shannon-Wiener index(H)as 1.9670,2.4975,2.6140 and 2.4356,respectively,characterized by their rise before drop and the shrub(herb)layer SD shows the maximum to be in the mixed coniferous-broadleaved(coniferous)forest(H arriving at 2.8625(1.5334)).In the vertical structure,on the other hand,for the sequenced coniferous forest,coniferous-broad mixed forest and Castnaopsis eyrei forest,the number of SD ranges in a decreasing order from the shrub,arbor to herb layer in contrast to the SD in a decreasing order of Schima superba forest ranging from the arbor to shrub and then to herb layer,and during the succession,the herb layer exhibits the maximum range of SD change among these layers,with its variation coefficients of 0.1572,0.0806,0.0899 and 0.1884 for H,J_(SW),J_(SI) and D,in order,in sharp contrast to the minimal SD range in the shrub layer,with the corresponding figures of 0.0482,0.0385,0.0142,and 0.1553.

南昌城市生态站站点冬季鸟类资源多样性

为了明确南昌城市生态站城区和近郊监测站点冬季鸟类资源多样性状况,通过样线法对南昌城区和近郊公园冬季鸟类资源开展调查。结果表明:在近郊公园省林科院内调查鸟类有40种,优势种为麻雀(Passer montanus)、珠颈斑鸠(Streptopelia chinensis)2种,艾溪湖湿地公园记录鸟类37种,优势种为白头鹎(Pycnonotus sinensis)、麻雀(Passer montanus)2种。香农-威纳指数(Shannon-Wiener)指数测度江西省林业科学院鸟类物种多样性(H')为3.168,均匀度(J)为0.853。艾溪湖湿地公园鸟类物种多样性(H')为3.249,均匀度(J)为0.914。省级保护鸟类在城郊公园中占本区域调查鸟类种类的26.83%,在城区公园中29.73%。丰富生境类型是提高鸟类多样性的有效措施。因此,在城市鸟类多样性保护的过程中,除了从鸟类栖息地生境考虑,还要结合单个绿地在城市环境中的位置进行考量。

浙江九龙山香果树生境土壤微生物多样性及其影响因素

【目的】揭示珍稀植物香果树Emmenopteryshenryi生境土壤微生物多样性变化信息及其影响因素,为香果树的保护和繁育提供参考。【方法】通过高通量测序技术检测了34个香果树群落生境的土壤细菌和真菌种类,分析海拔、坡向、土壤理化性质和香果树群落特征对土壤细菌和真菌多样性的影响。【结果】α多样性分析表明:九龙山香果树生境土壤细菌Shannon-Wiener指数均值为5.87,Simpson指数均值为0.98;土壤真菌Shannon-Wiener指数均值为4.88,Simpson指数均值为0.97。细菌Shannon-Wiener指数当量(H')随海拔升高而显著降低(P<0.05),随土壤pH(4.62~5.83)升高而显著升高(P<0.05);土壤细菌Simpson指数当量(D')与土壤速效钾呈显著负相关(P<0.05)。真菌H'和D'都随着海拔上升呈先下降后上升的趋势,且随碱解氮的升高而显著降低(P<0.05);真菌D'还与样地中心香果树胸高断面积呈显著正相关(P<0.05)。β多样性分析表明:细菌Sorenson相异性指数均值为0.39,其中物种周转组分贡献为70.2%,真菌Sorenson相异性指数均值为0.72,其中物种周转组分贡献为85.1%;细菌和真菌的Sorenson相异性指数各自存在显著空间自相关(P<0.05),且与土壤理化性质以及树种组成差异显著相关(P<0.05)。偏Mantel检验结果表明:细菌的物种周转组分与土壤理化性质和样地树种组成显著相关(P<0.05),而其物种丰富度组分仅与取样年份显著相关(P<0.05);真菌的物种周转组分存在显著空间自相关且与土壤理化性质差异显著相关(P<0.05),而其物种丰富度组分与取样年份、海拔都显著相关(P<0.05)。【结论】九龙山香果树生境土壤真菌多样性较高,细菌多样性较低;香果树生境土壤微生物多样性存在时空异质性,海拔、土壤碱解氮和香果树胸高断面积是土壤微生物α多样性的主要影响因素,土壤理化性质和样地树种组成是土壤微生物β多样性的主要影响因素。图4表2参32.

六盘山濒危稀有药用植物资源及保护等级评价

目的:六盘山蕴藏着丰富的濒危稀有药用植物资源。对六盘山濒危稀有药用植物进行调查,明确濒危稀有药用植物优先保护等级,为合理保护提供依据。方法:采用野外路线调查、样方调查和文献调研,并利用7项濒危植物优先保护等级评价指标,确定六盘山濒危稀有物种优先保护序列。结果:六盘山分布有濒危稀有药用植物25科39属53种,一级保护的药用植物有4种,二级保护的药用植物有7种,三级保护的药用植物有42种。濒危稀有药用植物自身的生物学特性和人为过度干扰是其致濒危的主要原因。结论:六盘山珍稀濒危药用植物亟待保护,建议按照保护等级因地制宜开展保护工作。