Climate-change habitat shifts for the vulnerable endemic oak species(Quercus arkansana Sarg.)

Quercus arkansana(Arkansas oak)is at risk of becoming endangered,as the total known population size is represented by a few isolated populations.The potential impact of climate change on this species in the near future is high,yet knowledge of its predicted effects is limited.Our study utilized the biomod2 R package to develop habi-tat suitability ensemble models based on bioclimatic and topographic environmental variables and the known loca-tions of current distribution of Q.arkansana.We predicted suitable habitats across three climate change scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5)for 2050,2070,and 2090.Our findings reveal that the current suitable habitat for Q.arkansana is approximately 127,881 km^(2) across seven states(Texas,Arkansas,Alabama,Louisiana,Mississippi,Georgia,and Florida);approximately 9.5%is encompassed within state and federally managed protected areas.Our models predict that all current suitable habitats will disap-pear by 2050 due to climate change,resulting in a northward shift into new regions such as Tennessee and Kentucky.The large extent of suitable habitat outside protected areas sug-gests that a species-specific action plan incorporating pro-tected areas and other areas may be crucial for its conserva-tion.Moreover,protection of Q.arkansana habitat against climate change may require locally and regionally focused conservation policies,adaptive management strategies,and educational outreach among local people.

Disentangling the effects of management and climate change on habitat suitability for saproxylic species in boreal forests

Forest degradation induced by intensive forest management and temperature increase by climate change are resulting in biodiversity decline in boreal forests.Intensive forest management and high-end climate emission scenarios can further reduce the amount and diversity of deadwood,the limiting factor for habitats for saproxylic species in European boreal forests.The magnitude of their combined effects and how changes in forest management can affect deadwood diversity under a range of climate change scenarios are poorly understood.We used forest growth simulations to evaluate how forest management and climate change will individually and jointly affect habitats of red-listed saproxylic species in Finland.We simulated seven forest management regimes and three climate scenarios(reference,RCP4.5 and RCP8.5)over 100 years.Management regimes included set aside,continuous cover forestry,business-as-usual(BAU)and four modifications of BAU.Habitat suitability was assessed using a speciesspecific habitat suitability index,including 21 fungal and invertebrate species groups.“Winner”and“loser”species were identified based on the modelled impacts of forest management and climate change on their habitat suitability.We found that forest management had a major impact on habitat suitability of saproxylic species compared to climate change.Habitat suitability index varied by over 250%among management regimes,while overall change in habitat suitability index caused by climate change was on average only 2%.More species groups were identified as winners than losers from impacts of climate change(52%–95%were winners,depending on the climate change scenario and management regime).The largest increase in habitat suitability index was achieved under set aside(254%)and the climate scenario RCP8.5(>2%),while continuous cover forestry was the most suitable regime to increase habitat suitability of saproxylic species(up to+11%)across all climate change scenarios.Our results show that close-to-nature management regimes(e.g.,continuous cover forestry and set aside)can increase the habitat suitability of many saproxylic boreal species more than the basic business-as-usual regime.This suggests that biodiversity loss of many saproxylic species in boreal forests can be mitigated through improved forest management practices,even as climate change progresses.

Assessment of the Characteristics of Demersal Fish Communities Using Species-and Trait-Based Approaches in the Coastal Habitats Along Rongcheng Bay,Shandong Peninsula,China

Biodiversity declines have motivated many studies on the relationship between species diversity and ecosystem functioning.In this study,we described the spatial-temporal characteristics of demersal fish communities along a coastal habitat in Rongcheng Bay,Shandong Peninsula,China with both species-based and biological trait-based approaches.The field survey was carried out monthly using traps from April to October of 2018,and divided into three seasons(spring:April and May;summer:June,July and August;autumn:September,October and November).The study area included five distinct habitats:seagrass bed,natural rocky reef,bare sand,artificial reef together with natural rocky reef,and artificial reef together with bare sand.We analyzed the fish communities with three taxonomic diversity indices,including Shannon-Wiener,Simpson,and Pielou Evenness,as well as four functional diversity indices,including FRic,FEve,FDiv,and FDis,based on 7 functional groups which are categorized into 27 traits.The results showed that there were no significant differences in taxonomic diversity indices among different habitats in the three seasons.However,significant differences were found in the functional richness of fish communities among different habitats in three seasons.Seagrass bed represented the highest functional richness in spring and autumn.This study demonstrates that seagrass bed is very important in enhancing the functional diversity of fish communities in a complex habitat.The study also indicates that the combination of taxonomic diversity and functional diversity will provide a more detailed description of the characteristics of fish communities.

Activity Pattern and Habitat Use of Shorebirds in an Artificial Wetland Complex:A Case Study of Breeding Pied Avocet in the Yellow River Delta,China

With the loss of substantial natural wetlands in coastal zones,artificial wetlands provide alternative habitats for many shorebirds.Scientific management of artificial wetlands used by shorebirds plays an important role in maintaining the stability of shorebird population.Satellite tracking technique can obtain high-precision location information of individuals day and night,providing a good technical support for the study of quantitative relationship between waterfowls and their habitats.In this study,satellite tracking method,Remote Sensing(RS)and Geographic Information System(GIS)technology were used to analyze the activity pattern and habitat utilization characteristics of Pied Avocet during breeding period in an artificial wetland complex in the Yellow River Delta(YRD),China.The results showed that the breeding Pied Avocets had a small range of activity,with a total core and main home range of 33.10 km^(2) and 216.30 km^(2),respectively.This species tended to forage in the pond and salt pan during the day and night,respectively,with an unfixed staying time in the breeding ground.The distance between breeding ground and feeding ground was less than 6 km.It is emphasized that in addition to improving the conditions of the remaining natural habitats,effective managing artificial habitats is a priority for shorebird conservation.This research could provide reference for the management of artificial wetlands in coastal zones and supply technique support for the protection of shorebirds and their habitats,and alleviate human-bird conflicts and sustainable development of coastal zones.

Island biogeography theory and the habitat heterogeneity jointly explain global patterns of Rhododendron diversity

Mountain biodiversity is of great importance to biogeography and ecology.However,it is unclear what ecological and evolutionary processes best explain the generation and maintenance of its high levels of species diversity.In this study,we determined which of six common hypotheses(e.g.,climate hypotheses,habitat heterogeneity hypothesis and island biogeography theory)best explain global patterns of species diversity in Rhododendron.We found that Rhododendron diversity patterns were most strongly explained by proxies of island biogeography theory(i.e.,mountain area)and habitat heterogeneity(i.e.,elevation range).When we examined other relationships important to island biogeography theory,we found that the planimetric area and the volume of mountains were positively correlated with the Rhododendron diversity,whereas the‘mountains-to-mainland’distance was negatively correlated with Rhododendron diversity and shared species.Our findings demonstrate that Rhododendron diversity can be explained by island biogeography theory and habitat heterogeneity,and mountains can be regarded as islands which supported island biogeography theory.

Habitat preferences and nest site selection by sympatric populations of Middle Spotted Woodpecker(Dendrocoptes medius) and Syrian Woodpecker(Dendrocopos syriacus) in natural mountain forests of Southwest Iran

We examined habitat preferences and nesting requirements of sympatric populations of Middle Spotted Woodpecker(Dendrocoptes medius) and Syrian Woodpecker(Dendrocopos syriacus).We carried out our study in 2015–2018 in natural mountain forests of Southwest Iran.We compared selected features of nesting,territory,and outside territory tree stands of the studied woodpeckers.The Middle Spotted Woodpecker occupied only oak forests,but the Syrian Woodpecker inhabited heterogenic forests that included the preferred tree of this species,the Mount Atlas Mastic.We recorded that in the breeding territories of the Middle Spotted Woodpecker,a greater area covered by tree crowns,as well as a larger number of trees,and a larger trunk basal area were observed in comparison to the territories occupied by the more plastic Syrian Woodpecker.Different habitat preferences demonstrated by both species could be a result of the selection of tree stands that provide the necessary food resources for each woodpecker species.Adaptation of Syrian Woodpecker to use heterogenic forest stands including tree species that produce fruits and as Mount Atlas Mastic trees,which likely allowed this species to colonise in Asia and Europe non-forest tree stands as orchards or gardens.Our results showed that poor tree condition and large tree trunk dimensions had a positive impact on the selection of nesting sites by both species.The presence of trees with large trunk dimensions was associated with multiple years of use of woodpecker breeding sites in the studied forests.Maintaining habitats in suitable condition for both studied woodpeckers can be achieved by preserving natural forests in the mountain regions of Iran.

Spatio-temporal evolution analysis of landscape pattern and habitat quality in the Qinghai Province section of the Yellow River Basin from 2000 to 2022 based on InVEST model

Habitat quality is an important indicator for evaluating the quality of ecosystem.The Qinghai Province section of the Yellow River Basin plays an important role in the ecological protection of the upper reaches of the Yellow River Basin.To comprehensively analysis the alterations of habitat quality in the Qinghai Province section of the Yellow River Basin,this study utilized the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model to calculate the habitat quality index and analyze the spatio-temporal variation characteristics of habitat quality in the study area from 2000 to 2022,and calculated seven landscape pattern indices(number of patches,patch density,largest patch index(LPI),landscape shape index(LSI),contagion index(CONTAG),Shannon diversity index,and Shannon evenness index)to research the variation of landscape pattern in the study area.The results showed that the number of patches,patch density,LPI,LSI,Shannon diversity index,and Shannon evenness index increased from 2000 to 2022,while the CONTAG decreased,indicating that the landscape pattern in the Qinghai Province section of the Yellow River Basin changed in the direction of distribution fragmentation,shape complexity,and heterogeneity.The average value of the habitat quality index in the Qinghai Province section of the Yellow River Basin from 2000 to 2022 was 0.90.Based on the value of habitat quality index,we divided the level of habitat quality into five categories:lower(0.00-0.20),low(0.20-0.40),moderate(0.40-0.60),high(0.60-0.80),and higher(0.80-1.00).Most areas were at the higher habitat quality level.The lower habitat quality patches were mainly distributed in Longyang Gorge and Yellow River-Huangshui River Valley.From 2000 to 2022,the habitat quality in most areas was stable;the increase areas were mainly distributed in Guinan County,while the decrease areas were mainly distributed in Xining City,Maqen County,Xinghai County,Qumarleb County,and Darlag County.To show the extent of habitat quality variation,we calculated Sen index.The results showed that the higher habitat quality area had a decrease trending,while other categories had an increasing tendency,and the decreasing was faster than increasing.The research results provide scientific guidance for promoting ecological protection and high-quality development in the Qinghai Province section of the Yellow River Basin.

Riparian habitat quality as an indicator of land use/land cover effects on riverine water quality

Riparian land use/land cover(LULC)plays a crucial role in maintaining riverine water quality by altering the transport of pollutants and nutrients.Nevertheless,establishing a direct relationship between water quality and LULC is challenging due to the multi-indicator nature of both factors.Water quality encompasses a multitude of physical,chemical,and biological parameters,while LULC represents a diverse array of land use types.Riparian habitat quality(RHQ)serves as an indicator of LULC.Yet,it remains to be seen whether RHQ can act as a proxy of LULC for assessing the impact of LULC on riverine water quality.This study examines the interplay between RHQ,LULC and water quality,and develops a comprehensive indicator to predict water quality.We measured several water quality parameters,including pH(potential of hydrogen),TN(total nitrogen),TP(total phosphorus),T_(water)(water temperature),DO(dissolved oxygen),and EC(electrical conductivity)of the Yue and Jinshui Rivers draining to the Han River during 2016,2017 and 2018.The water quality index(WQI)was further calculated.RHQ is assessed by the InVEST(Integrated Valuation of Ecosystem Services and Tradeoffs)model.Our study found noticeable seasonal differences in water quality,with a higher WQI observed in the dry season.The RHQ was strongly correlated with LULC compositions.RHQ positively correlated with WQI,and DO concentration and vegetation land were negatively correlated with T_(water),TN,TP,EC,cropland,and construction land.These correlations were stronger in the rainy season.Human-dominated land,such as construction land and cropland,significantly contributed to water quality degradation,whereas vegetation promoted water quality.Regression models showed that the RHQ explained variations in WQI better than LULC types.Our study concludes that RHQ is a new and comprehensive indicator for predicting the dynamics of riverine water quality.

Estimation of Potential Habitat of Caragana acanthophylla in Xinjiang Based on Maximum Entropy Model

[Objectives]To determine the potential habitat range of Caragana acanthophylla in Xinjiang.[Methods]The known distribution points of C.acanthophylla were used as samples,and a MaxEnt model was developed based on their climatic variables to identify key environmental factors affecting the potential habitats of C.acanthophylla through jackknife method and construction of a response relationship between representative variables and habitat suitability;the suitability of habitats for C.acanthophylla in Xinjiang was evaluated based on the output results of the model.[Results](i)The accuracy of the model verified by AUC curve was 0.971,indicating that the potential habitats of C.acanthophylla in Xinjiang predicted by MaxEnt model were highly credible.(ii)The optimum climatic characteristics for the distribution of C.acanthophylla in Xinjiang were:isothermality 18.8%-34%,minimum temperature of coldest month-30℃to-13℃,mean temperature of coldest quarter-18℃ to-4℃,annual precipitation 80-410 mm,precipitation of driest month 0-25 mm,precipitation of driest quarter 0-82 mm,and precipitation of coldest quarter 0-75 mm.(iii)The total potential distribution area of C.acanthophylla in Xinjiang was modeled to be 1.03×10^(5) km^(2),of which 8.54×10^(3)km^(2) was high suitability area,mainly in the front mountain belt of the north slope of Tianshan Mountain in Urumqi City,Changji Hui Autonomous Prefecture,Bortala Mongol Autonomous Prefecture,and Yili Kazak Autonomous Prefecture and the front mountain belt of Barluk Mountain in Tacheng Prefecture.[Conclusions]This study is of great significance for the future scientific management,regeneration,vegetation restoration and ecological protection of C.acanthophylla.

Influence of Human Activity Intensity on Habitat Quality in Hainan Tropical Rainforest National Park,China

Due to long-term human activity interference,the Hainan Tropical Rainforest National Park(HTRNP)of China has experienced ecological problems such as habitat fragmentation and biodiversity loss,and with the expanding scope and intensity of human activity impact,the regional ecological security is facing serious challenges.A scientific assessment of the interrelationship between human activity intensity and habitat quality in the HTRNP is a prerequisite for achieving effective management of ecological disturbances caused by human activities and can also provide scientific strategies for the sustainable development of the region.Based on the land use change data in 2000,2010,and 2020,the spatial and temporal variations and the relationship between habitat quality(HQ)and human activity intensity(HAI)in the HTRNP were explored using the integrated valuation of ecosystem services and trade-offs(InVEST)model.System dynamics and land use simulation models were also combined to conduct multi-scenario simulations of their relationships.The results showed that during 2000–2020,the habitat quality of the HTRNP improved,the intensity of human activities decreased each year,and there was a negative correlation between the two.Second,the system dynamic model could be well coupled with the land use simulation model by combining socio-economic and natural factors.The simulation scenarios of the coupling model showed that the harmonious development(HD)scenario is effective in curbing the increasing trend of human activity intensity and decreasing trend of habitat quality,with a weaker trade-off between the two compared with the baseline development(BD)and investment priority oriented(IPO)scenarios.To maintain the authenticity and integrity of the HTRNP,effective measures such as ecological corridor construction,ecological restoration,and the implementation of ecological compensation policies need to be strengthened.

Enhanced Species Diversity Unlocked by Habitat Conservation in Agricultural Landscapes: New Perspectives on Ecological Weed Management and Sustainable Intensification—Species Diversity and Habitat Conservation

The impulse to remain profitable by increasing agricultural production levels in view of the greater demand for food, provided impetus to production intensification. The aim of this review is to summarise current literature, reporting specifically on the impact of production intensification on habitats and yield constraints caused by weeds. Secondly, in alleviating these effects over the short term, ecological measures that enhance species diversity in conserved habitats and promote semi-natural habitats in the agricultural landscape, are discussed. In large-scale intensive agriculture, weed control is predominantly rooted in agrochemical applications in the form of herbicides. Long lasting intensive agricultural practices show discord both with the promotion of the biodiversity of microbes belowground and aboveground and with organisms involved in the breaking down of plant material. The presence of native species in the surroundings, in combination with hedgerows and field margins, with a comparatively intricate and balanced variety of plants in a sheltered environment, are essential for settlement of benign insects, particularly in the face of intensive agricultural production. The promising tactic of advantageous seed predators enables decreased herbicide applications. Crop mosaics arranged to advance compatibility at the landscape scale are important to bolster pollination services and insect management, while ecological variety in the surroundings acts as a safety net for habitat diversity. Weed control in combination with different tactics of vegetation use, comprising cover cropping, hedgerows and field margins, sets up safe havens in the landscape, and improves the diffusion of complementary life forms. Field margins perform a meaningful natural function as point of provision for forage, safe havens and distribution passageways for pollinators and insect predators. Production practices that promote more heterogeneity and combine high density semi-natural safe havens and habitat conservation in agro ecosystems are beneficial to species diversity across trophic levels and contribute to agricultural production stability and food safety.

Relative importance of tidal flats and artificial habitats for two spoonbill species and related interspecific differences

Artificial/seminatural environments,such as aquacultural ponds,saltpans,and croplands,have recently been acknowledged as important habitats for coastal waterbirds.Although coastal waterbirds tend to use artificial habitats around tidal flats as roosting sites during high-tide,it remains unclear whether the importance of surrounding habitats relative to tidal flats varies among landscape types,seasons,species,or tidal conditions.The Black-faced Spoonbill(Platalea minor)and Eurasian Spoonbill(P.leucorodia)are two closely related sympatric species in East Asia with narrow and wide distribution ranges and habitat requirements,respectively.We therefore expect that both species will use surrounding artificial habitats across seasons at high tides,but Blackfaced Spoonbills will use them less frequently than Eurasian Spoonbills.Here,we address these hypotheses in the Imazu tidal flat and its surrounding environments in southern Japan.We investigated the habitat use and behavioral patterns of both species through route and behavioral surveys during the fall migration and wintering seasons in 2021.We found that both species used surrounding habitats including artificial ones more frequently than the tidal flat regardless of the tidal condition or season,but spoonbills used these habitats more frequently in winter than in autumn.We also found that Eurasian Spoonbills foraged in surrounding artificial habitats more frequently than Black-faced Spoonbills.These results not only demonstrate how coastal waterbirds exploit surrounding habitats relative to tidal flats but also suggest that the importance of surrounding habitats varies among species and seasons.Our study thus emphasizes that valuing and managing surrounding habitats in addition to tidal flats are key to conserving globally declining waterbirds.

Spatiotemporal evolution and prediction of habitat quality in Hohhot City of China based on the InVEST and CA-Markov models

With the acceleration of urbanization,changes in the urban ecological environment and landscape pattern have led to a series of prominent ecological environmental problems.In order to better coordinate the balanced relationship between city and ecological environment,we selected land use change data to evaluate the habitat quality in Hohhot City of China,which is of great practical significance for regional urban and economic development.Thus,the integrated valuation of ecosystem services and tradeoffs(InVEST)and Cellular Automata-Markov(CA-Markov)models were used to analyze,predict,and explore the Spatiotemporal evolution path and characteristics of urban land use,and forecast the typical evolution pattern of land use in 2030.The results showed that the land use types in Hohhot City changed significantly from 2000 to 2020,and the biggest change took place in cultivated land,grassland,shrub,and artificial surface.The decrease of cultivated land area and the increase of artificial surface area were the main impact trend of land use change.The average value of habitat quality had been decreasing continuously from 2000 to 2020,and the values of habitat degradation were 0.2605,0.2494,and 0.2934 in 2000,2010,and 2020,respectively,showing a decreasing trend.The decrease of habitat quality was caused by the needs of economic development and urban construction,as well as the impact of land occupation.During this evolution,many cultivated land and urban grassland had been converted into construction land.The simulated land use changes in 2030 are basically the same as those during 2000-2020,and the habitat quality will still be declining.The regional changes are influenced by the urban rapid development and industrial layout.These results can provide decision-making reference for regional urban planning and management as well as habitat quality evaluation.

Impact of climate change on potential habitat distribution of Sciaenidae in the coastal waters of China

Climate change has affected and will continue to affect the spatial distribution patterns of marine organisms.To understand the impact of climate change on the distribution patterns and species richness of the Sciaenidae in China’s coastal waters,the maximum entropy model was used to combine six environmental factors and predict the potential distribution of 12 major species of Sciaenidae by 2050s under Representative Concentration Pathways(RCPs)2.6 and 8.5.The results showed that the average area under the receiver operating characteristic curve of the model was 0.917,indicating that the model predictions were accurate and reliable.The main driving factors affecting the potential distribution of these fishes were dissolved oxygen,salinity,and sea surface temperature(SST).There was an overall northward shift in the potential habitat areas of these fishes under the two climate scenarios.The total potential habitat areas of Larimichthys polyactis,Pennahia argentata,and Pennahia pawak decreased under both climate scenarios,while the total habitat area of Johnius belengerii,Pennahia anea,Miichthys miiuy,Collichthys lucidus,and Collichthys niveatus increased,suggesting that these might be loser and winner species,respectively.The expansion rate,contraction rate,degree of centroid change,and species richness in the potential habitats were generally more significant under RCP8.5 than RCP2.6.The mean shift rates of the potential distribution were 41.50 km/(10 a) and 29.20 km/(10 a) under RCP8.5 and RCP2.6,respectively.The changes in Sciaenidae species richness under climate change were bounded by the Changjiang River Estuary waters,with obvious north-south differences.Some waters with increased species richness may become refuges for Sciaenidae fishes under climate change.The richness and habitat area change rate of some aquatic germplasm resources will decrease,meanings that these reserves are more sensitive to climate change,and more attention should be paid to the potential challenges and opportunities for fishery managers.This study may provide a scientific basis for the management and conservation of Sciaenidae in China under climate change.

Response of Distribution Range Against Climate Change and Habitat Preference of Four National Protected Diploderma Species in Tibetan Plateau

Understanding the spatial distribution and habitat preference for rare and endangered species are essential for effective conservation practice.We examined the spatial distribution and habitat preference of four Diploderma species(Diploderma drukdaypo,D.laeviventre,D.batangense,and D.vela),which are endemic to the Qinghai-Tibet Plateau and are currently under state protection.We used the ensembles of small models(ESM)approach and predicted potential distribution ranges of the species in current and two future climate scenarios(SSP126 and SSP585).The degree of overlap between the predicted distribution ranges and existing natural reserves was further analyzed.Habitat preference was examined using a paired quadrat method.Our results predicted that D.drukdaypo has a current distribution range of 600 km^(2),which would decrease to 50 km^(2)and 55 km^(2)under the SSP126 and SSP585 respectively.For D.laeviventre,the current distribution range is 817 km^(2),with minimum changes in the two future climate scenarios(774 km^(2)and 902 km^(2)).For D.batangense,the current distribution range is 875 km^(2),which would expand to 1522 km^(2)and 3340 km^(2)in the two future climate scenarios.Similarly for D.vela,the current distribution range is 1369 km^(2),which would change to 1825 km^(2)and 2043 km^(2)respectively under the two future climate scenarios.The effect of protection of current nature reserves are likely low for those species;we found no overlap(D.drukdaypo,D.laeviventre)or little overlap(D.batangense 2.04%–3.56%,D.vela 15.52%–16.87%)between the currently designated protection area and distribution range under current and future climate scenarios.For habitat preference,stones appear to be the critical habitat element for those species although different species had different stone requirements.Taken together,we provided critical information on potential distribution ranges and habitat preference for four endangered Diploderma species,and confirmed the inadequacy of current nature reserves.The establishment of new or expansion of existing nature reserves is urgent for the conservation of those species.

Changes in wintering Hooded Cranes and their habitats at Chongming Dongtan over the past 20 years

The Hooded Crane(Grus monacha)is listed as a Vulnerable species in the IUCN red list.Tidal wetland(tideland),the major habitat for wintering Hooded Cranes at East China’s Chongming Dongtan,has dramatically changed in the past two decades,but there is limited knowledge about the population and habitat changes of the Hooded Cranes.This study investigated the population size and distribution of wintering Hooded Cranes at Chongming Dongtan from 2000 to 2021.We used remote sensing images combined with a vegetation classification algorithm to analyse the distribution of saltmarsh vegetation.The quadrat method was used to investigate the density and weight of the underground corms of Sea Bulrush(Scirpus mariquter),the main food on tideland for the Hooded Cranes.From 2000 to 2021,the population number of wintering Hooded Cranes at Chongming Dongtan remained stable at approximately 100.In 2000,the area of Scirpus spp.and Common Reed(Phragmites australis)accounted for approximately half of the total saltmarsh area at Chongming Dongtan,respectively.The invasive Smooth Cordgrass(Spartina alterniflora)rapidly expanded on tideland in the 2000s while the Scirpus spp.was competed out and thus significantly reduced in area.After the implementation of an ecological project to control Smooth Cordgrass and to restore Scirpus spp.in the 2010s,the area of the Smooth Cordgrass decreased considerably while the area of Scirpus spp.increased.The corms of Sea Bulrush decreased on the southeastern tideland during the study period,which might be the cause of the northward movement of the foraging Hooded Cranes on tideland.We also found Hooded Cranes foraged crops in the nearby farmland in mid-winter,causing human-bird conflicts in the recent decade.Our results found that changes in habitat and food conditions on tideland impacted wintering Hooded Cranes.Foraging in farmland with human disturbance in the recent decade might be related to insufficient food on tideland.We suggest active intervention to accelerate the restoration of Sea Bulrush on tideland and reduce human disturbance in farmland to improve the habitat quality of the wintering Hooded Crane at Chongming Dongtan.

Three-dimensional assessment of movement patterns of Sichuan snub-nosed monkeys affected by habitat structure in temperate forests

DEAR EDITOR,Movement patterns can reflect species-specific characteristics of individuals and animal groups at a given scale. Accurate three-dimensional(3D) assessment can quantify the relationship between movement patterns of an animal and its unique habitat. Here, we evaluated the effects of habitat structure on movement patterns of the golden snub-nosed monkey(Rhinopithecus roxellana). We used airborne light detection and ranging(LiDAR) to map the 3D structure of the temperate forest in the Qinling Mountains(Shaanxi, China).

Ensemble habitat suitability modeling of stomatopods with Oratosquilla oratoria as an example

Stomatopods are better known as mantis shrimp with considerable ecological importance in wide coastal waters globally. Some stomatopod species are exploited commercially, including Oratosquilla oratoria in the Northwest Pacific. Yet, few studies have published to promote accurate habitat identification of stomatopods, obstructing scientific management and conservation of these valuable organisms. This study provides an ensemble modeling framework for habitat suitability modeling of stomatopods, utilizing the O. oratoria stock in the Bohai Sea as an example. Two modeling techniques(i.e., generalized additive model(GAM) and geographical weighted regression(GWR)) were applied to select environmental predictors(especially the selection between two types of sediment metrics) that better characterize O. oratoria distribution and build separate habitat suitability models(HSM). The performance of the individual HSMs were compared on interpolation accuracy and transferability.Then, they were integrated to check whether the ensemble model outperforms either individual model, according to fishers’ knowledge and scientific survey data. As a result, grain-size metrics of sediment outperformed sediment content metrics in modeling O. oratoria habitat, possibly because grain-size metrics not only reflect the effect of substrates on burrow development, but also link to sediment heat capacity which influences individual thermoregulation. Moreover, the GWR-based HSM outperformed the GAM-based HSM in interpolation accuracy,while the latter one displayed better transferability. On balance, the ensemble HSM appeared to improve the predictive performance overall, as it could avoid dependence on a single model type and successfully identified fisher-recognized and survey-indicated suitable habitats in either sparsely sampled or well investigated areas.

Habitats shape root-associated fungal and bacterial communities of Minjiang fir saplings

Root-associated microbes play an essentialrole in mediating plant growth,health,and habitat adaptability.However,it is unknown which microbial taxa help develop host fitness and how habitats shape root-associated microbial assembly patterns.As an endemic species of subalpine forests in western Sichuan,China,Minjiang fir(Abies fargesii var.faxoniana)is dominant on cold-shaded northwestern slopes while absent on warm sunlit southwestern slopes.In this study,fungal and bacterial communities were investigated in three spatial compartments(endosphere,rhizosphere,and bulk soil)associated with Minjiang fir saplings on a cold-shaded northwestern slope and a warm sunlit southwestern slope.Habitats differentiated the microbial communities regardless of the spatial compartment and microbial taxa.Slope aspect variations caused shifts in root-associated(rhizosphere and endosphere)microbial compositions.Compared with the southwestern slope,the cold-shaded northwestern slope harbored a higher abundance of the growth-promoting bacteria Burkholderia and ectomycorrhizal fungi Cortinarius and Piloderma.The slope aspect had stronger effects on fungal diversity than bacterial diversity,with higher fungal endemism and lower bacterial endemism.Slope aspect variations were the dominant drivers of root-associated microbial communities,with lower contribution by soil properties and higher contribution by plant traits on the northwestern slope.Findings from this study could improve the understanding of plant habitat adaptability from the perspective of microbial community assembly.It is suggested that forest management should consider root-associated microbiomes for enhancing species fitness and habitat adaptability.

Trees species’ dispersal mode and habitat heterogeneity shape negative density dependence in a temperate forest

Conspecific negative density dependence(CNDD)is a potentially important mechanism in maintaining species diversity.While previous evidence showed habitat heterogeneity and species’dispersal modes affect the strength of CNDD at early life stages of trees(e.g.,seedlings),it remains unclear how they affect the strength of CNDD at later life stages.We examined the degree of spatial aggregation between saplings and trees for species dispersed by wind and gravity in four topographic habitats within a 25-ha temperate forest dynamic plot in the Qinling Mountains of central China.We used the replicated spatial point pattern(RSPP)analysis and bivariate paircorrelation function(PCF)to detect the spatial distribution of saplings around trees at two scales,15 and 50 m,respectively.Although the signal was not apparent across the whole study region(or 25-ha),it is distinct on isolated areas with specific characteristics,suggesting that these characteristics could be important factors in CNDD.Further,we found that the gravity-dispersed tree species experienced CNDD across habitats,while for wind-dispersed species CNDD was found in gully,terrace and low-ridge habitats.Our study suggests that neglecting the habitat heterogeneity and dispersal mode can distort the signal of CNDD and community assembly in temperate forests.