Ecological Niche Modelling Reveals the Peculiarities of Ecological Disjunction Between Two Sympatric Racerunners in Kazakhstan:Eremias lineolata(Nikolsky,1897)and Eremias scripta(Strauch,1867)

The ecological-niche models for two sympatric species,Eremias lineolata(Nikolsky,1897)and Eremias scripta(Strauch,1867),reveal evidence of spatial and temporal disjunction in the actual niches of both species.Eremias lineolata demonstrates a wide range of adaptations and,at the same time,has a greater need for winter precipitation and minimal temperature than E.scripta.Possible explanations for the thermal diversity of both species are provided.Thermal variables(monthly temperatures,monthly solar radiation,etc.)are traditionally important for ectotherm animals.Interestingly,as many as half of the key variables in both species are related to different aspects of environmental water balance(precipitation,air humidity,vapor pressure).There are several ways in which moisture may impact the lizard’s life cycle.Soil humidity is related to soil temperature and may be important during winter hibernation.In summer,soil humidity may support successful embryogenesis.Precipitation during the warm months is a key factor in maintaining the moisture content of the soil.In winter,snow cover provides a better thermal balance of the soil’s top layers where winter shelters are housed.Ecological niche modeling(ENM)is an interdisciplinary approach combining the geographical,climatic,ecological,and biological aspects of the wellbeing of species.This interdisciplinary approach lifts biological studies onto a new,integrative level,providing a comprehensive view on species biology and answering the questions that might not be answered if the traditional methods for studying animals were used alone.

Spatio-temporal differentiation of landscape ecological niche in western ecological frangible region： A case study of Yan＇an region in northwestern China

In this study, we attempt to put forward a conception of landscape ecological niche, enlightened by international scholars on extending the ecological niche theory from spatial niche to functional niche. That is helpful for comprehensively appraising landscape spatial patterns and ecological functions, also, presents a new method for analyzing landscape features from multidimensional aspects. The practice process is demonstrated by taking Yan＇an region in northwestern China as a case. Firstly, the indices system including spatial attribute and functional attribute is established for assessing landscape ecological niche. Additionally, two-dimensional figures are drawn for comparing the spatio-temporal features of landscape ecological niche in 1987 and 2000 among the 13 administrative counties. The results show that from 1987 to 2000, towards Yan＇an region, spatial attribute value of landscape ecological niche changes from 1.000 to 1.178 with an obvious increment, and functional attribute value changes from 0.989 to 1.069 with a little increment, both of which enhance the regional landscape ecological niche. Towards each county, spatial attribute value of landscape ecological niche increases to different extent while functional attribute value changes dissimilarly with an increment or a decrement.

Human Settlement Evaluation in Mountain Areas Based on Remote Sensing,GIS and Ecological Niche Modeling

The Qinghai-Tibet Plateau is the word＇s highest and largest plateau. Due to increasing demands for environment exploration and tourism, a large transitional area is required for altitude adaptation. Hehuang valley, which locates in the transition zone between the Loess Plateau and the Qinghai-Tibet Plateau, has convenient transportation and relatively low elevation. Our question is whether the geographic conditions here are appropriate for adapted stay before going into the Qinghai-Tibet Plateau. Therefore, in this study, we examined the potential use of ecological niche modeling （ENM） for mapping current and potential distribution patterns of human settlements. We chose the Maximum Entropy Method （Maxent）, an ENM which integrates climate, remote sensing and geographical data, to model distributions and assess land suitability for transition areas. After preprocessing and selection, the correlation between variables and spatial auto- correlation input data were removed and 106 occurrence points and 9 environmental layers were determined as the model inputs. The threshold- independent model performance was reasonable according to lO times model running, with the area under the curve （AUC） values being 0.917± 0.01, and 0.923±0.002 for test data. Cohen＇s kappa coefficient of model performance was 0.848. Results showed that 82.22% of the study extent was not suitable for human settlement. Of the remaining areas, highly suitable areas aceounted for 1.19%, moderately for 5.3% and marginally for 11.28%. These suitable areas totaled 418.79 km2, and 86.25% of the sample data was identified in the different gradient of suitable area.The decisive environmental factors were slope and two climate variables： mean diurnal temperature range and temperature seasonality. Our model showed a good performance in mapping and assessing human settlements. This study provides the first predicted potential habitat distribution map for human settlement in Ledu County, which could also help in land use management.

Predicting the potential geographic distribution of Bactrocera bryoniae and Bactrocera neohumeralis(Diptera: Tephritidae) in China using MaxEnt ecological niche modeling

Bactrocera bryoniae and Bactrocera neohumeralis are highly destructive and major biosecurity/quarantine pests of fruit and vegetable in the tropical and subtropical regions in the South Pacific and Australia.Although these pests have not established in China,precautions must be taken due to their highly destructive nature.Thus,we predicted the potential geographic distribution of B.bryoniae and B.neohumeralis across the world and in particular China by ecological niche modeling of the Maximum Entropy(Max Ent)model with the occurrence records of these two species.Bactrocera bryoniae and B.neohumeralis exhibit similar potential geographic distribution ranges across the world and in China,and each species was predicted to be able to distribute to over 20%of the globe.Globally,the potential geographic distribution ranges for these two fruit fly species included southern Asia,the central and the southeast coast of Africa,southern North America,northern and central South America,and Australia.While within China,most of the southern Yangtze River area was found suitable for these species.Notably,southern China was considered to have the highest risk of B.bryoniae and B.neohumeralis invasions.Our study identifies the regions at high risk for potential establishment of B.bryoniae and B.neohumeralis in the world and in particular China,and informs the development of inspection and biosecurity/quarantine measures to prevent and control their invasions.

Evolution of biogeographic disjunction between eastern Asia and North America in Chamaecyparis:Insights from ecological niche models

The disjunct distribution of plants between eastern Asia(EA) and North America(NA) is one of the most well-known biogeographic patterns. However, the formation and historical process of this pattern have been long debated. Chamaecyparis is a good model to test previous hypotheses about the formation of this disjunct pattern as it contains six species disjunctly distributed in EA, western North America(WNA)and eastern North America(ENA). In this study, we applied ecological niche models to test the formation of the disjunct pattern of Chamaecyparis. The model calibrated with the EA species was able to predict the distribution of eastern NA species well, but not the western NA species. Furthermore, the eastern Asian species were shown to have higher niche overlap with the eastern North American species. The EA species were also shown to share more similar habitats with ENA species than with WNA species in the genus. Chamaecyparis species in WNA experienced a significant niche shift compared with congeneric species. Chamaecyparis had a low number of suitable regions in Europe and the middle and western NA during the Last Glacial Maximum(LGM) period, and became extinct in the former region whereas it retains residual distribution in the latter. The extirpations in western NA and Europe in response to the late Neogene and Quaternary climatic cooling and the more similar habitats between ENA and EA ultimately shaped the current intercontinental disjunct distribution of Chamaecyparis. Both current hypotheses may be also jointly applied to explain more eastern Asian and eastern North American disjunctions observed today.

Epiphytic orchids and their ecological niche under anthropogenic influence in central Himalayas,Nepal

The survival chance of epiphytie orchids today not only depends on the natural site conditions required by the orchids but also on anthropogenic changes in site conditions. This study answers two questions： （1） What is the ecological niche of the different epiphytic orchid species？ （2） What are the ecological factors that threaten epiphytic orchid＇s population under anthropogenic disturbances？ Our study area was the Kathmandu valley, Nepal, with its subtropical forest. We established 156 systematically selected sampling points in the Kathmandu area covering different types of ecosystems under human impacts such as densely populated area, agricultural land, mixed agricultural and settled area, old tree patches, and a natural forest in a national park. The ecological niche of the orchid species was analyzed with a principal component analysis （PCA）. The correlations between the different site factors were statistically significant. Spearman＇s rank correlation matrices showed that the variables land-use intensities with altitude, and height with diameter in breast height （dbh） of host had the highest significant positive correlation coefficient （0.67 and 0.64 respectively）. On the other hand, host bark pH and altitude as well as land use had a significantly strong negative correlation coefficient （-0.80 and -0.61, respectively）. Different epiphytic orchid species interact differently with the given set of environmental factors： for occurrence of Vanda cristata there is no single environmental factor of special influence, while for Rhynehostylis retusa high bark pH and high light availability are important. First two axis of the PCA explained more than 50% of the total variance. Most orchid species occupy a specific, narrow niche in this ecological space. The main causes of anthropogenie influence of orchid population in the Kathmandu Valley are loss of adequate host trees （species and size） and increasing air pollution, resulting in increasing host bark pH.

Invasive sequence and ecological niche of main insect borers of Larix gmelinii forest in Aershan, Inner Mongolia

After the outbreak of Dendrolimus superans Buter in 2002, many insect borers quickly invaded larch （Larix gmelinii Rupr.） forests in the Aershan of Inner Mongolia. Methods involved included setting sample plots, collecting adults in iron traps and measuring areas of galleries to study the invasive sequence, their ecological niche and the extent of the different effects by the main insect borers to their hosts. The results showed that the damage of D. superans weakened L. gmelinii, first Ips subelongatus Motschulsky invaded, followed by Acanthocinus carinulatus Gebler, Monochamus urussovi Fisher and M. sutor L. After the outbreak of D. superans, the average density of longhorn beetles per L. gmelinii tree increased. The ecological niche of Ips subelongatus stretches almost from the base to the top of the trunk. The number of insects in older stands of L. gmelinii is larger than those in middle aged stands. They do not damage healthy trees of L. gmelinii. The ecological niche of A. carinulatus is higher in dead L. gmelinii trees than in weak ones. The degree of damage is directly proportional with age and depth of bark. M. urussovi mainly damages trunks below 4 m in weak trees; in dead trees they can do damage up to 6 m in height. M. sutor mainly damages trunks below 5 m in weak L. gmelinii trees; in dead trees they cause damage up to 7 m. Again, the degree of damage is directly proportional with age. None of the three species of longhorn beetles damage healthy L. gmelinii and younger trees. Among the main insect borers, the degree of damage caused by I. subelongatus is more serious than that of other insects.

Effects of dietary replacement of soybean meal with dried distillers grains with solubles on the microbiota occupying different ecological niches in the rumen of growing Hu lambs

Background:Diet has a profound impact on the rumen microbiota,and the impact can vary among the different rumen ecological niches(REN).This study investigated the effects of dietary replacement of soybean meal(SBM)with dried distillers grains with solubles(DDGS)on the rumen microbiota occupying different REN of growing Hu lambs.After a 9-week feeding trial,6 lambs from each dietary treatment(SBM vs.DDGS-based diets)were slaughtered for sample collection.The microbiota of the rumen solid,liquid,and epithelium fractions was examined using amplicon sequencing analysis of bacterial 16S rRNA gene,functional prediction,and qPCR.Results:No interaction of dietary protein source(PS)and REN were detected for virtually all the measurements made in this study.The DDGS substitution resulted in very limited influence on bacterial community structure.However,the metabolic pathways predicted from 16S rRNA gene sequences varied greatly between SBM-and DDGS-based diets.The populations of rumen total bacteria,fungi,sulfate-reducing bacteria(SRB),and methanogens were not influenced by DDGS substitution,but the population of protozoa was reduced.The bacterial communities in rumen solid(RS)and liquid(RL)were similar in taxonomic composition but were different in relative abundance of some taxa.In contrast,the bacterial composition and relative abundance of rumen epithelium(RE)were greatly distinct from those of the RS and the RL.In alignment with the bacterial relative abundance,the metabolic pathways predicted from 16S rRNA genes also varied greatly among the different REN.The populations of total bacteria,protozoa,and methanogens attached to the RE were smaller than those in the RS and RL,and the fungal population on the rumen epitheliumwas smaller than that in the RS but similar to that in the RL.On the contrary,the SRB population on the RE was greater than that in the RS and RL.Conclusions:Substitution of SBM with DDGS had greater impact to the protozoa than to the other microbes,and the microbial community structure and functions at different REN are distinct and niche-adapted.

The Empirical Study of Web-based Teacher's Ecological Niche

Based on the previous research results and five principles,this paper tries to build an applicable optimization framew ork of college English classroom teaching,w hich centers on teacher development.According to this framew ork,teacher development should include the modernized teacher development framew ork w ith the core ideas of optimizing the teachers’perception,teachers’information literacy,and diversified teaching methods,in w hich the concepts of teachers’self-development and life-long learning are emphasized.M oreover,the four important supporting contents w ere proposed:the teacher autonomy,the construction of intelligent teacher development platform,perfecting the training organization,and the informationization of teachers’training.

Prediction of Dry Dipterocarp Forest Distribution Using Ecological Niche Model in Ping Basin of Northern Thailand

DDF （dry dipterocarp forest） is importantly deciduous forest type in Thailand since it consists of important tree species for timber products and non-timber products. So, people would like to come to use these products for daily uses in this forest type. The main aim of this study is to evaluate significant biophysical factors for DDF distribution using factor analysis and to model DDF distribution using ENFA （ecological niche factor analysis）. In this study, 13 watersheds of Ping Basin in northern Thailand were selected as the study site based on availability of forest inventory data in 2007 from DNP （Department of National Parks, Wildlife and Plant Conservation）. Basic biophysical data for data analysis included forest inventory data （179 DDF plots）, 10 climatic data, three topographic data, and one soil data. For identification and evaluation of biophysical factors for DDF distribution using factor analysis, the first three factors, namely DDF-1, DDF-2 and DDF-3, had been extracted with 95.35% of total variance. These three components were used to predict DDF distribution based on HS （habitat suitability） with ENFA. In practice, the results were validated with AVI （absolute validation index） and CVI （contrast validation index） with validated forest inventory dataset. This evaluation shows that DDF-2 model is the best HS data consisting of four physical factors （mean annually temperature, mean monthly maximum temperature, mean monthly minimum temperature, and elevation）, which is able to effectively used for habitat suitability for DDF distribution prediction. It was found that habitat suitability for DDF distribution can be classified into four classes including high suitable habitat, moderate suitable habitat, low suitable habitat, and unsuitable habitat. As a result, DDF distributions with high suitable habitat are highly related with DDF forest inventory plots of DNP. Thus, the obtained output can be further used for DDF rehabilitation according to climate and topographic factors.

Research on Educating College Students’ Ecological Values from the Perspective of Marxist Ecological View

The Marxist ecological view suggests a dialectical relationship between humans and nature.Only by integrating the initiative of human beings with developing laws of the nature,can we achieve the harmonious coexistence and development of humans and nature.From the perspective of Marxist ecological view,colleges should strengthen the education of college students’ecological values and guide them to have a deeper command of the true nature of Marxist ecological view.The author explores and analyzes the Marxist ecological view,and come up with an effective strategy for teaching college students’ecological values under the Marxist ecological view,hoping to help college students develop correct ecological values.

Study on the Ecological Ethics of Agricultural College Students

From the perspective of environmental sociology,a questionnaire survey was conducted on the environmental awareness and behaviors of undergraduates from nearly all fields of majors in Sichuan Agricultural University. According to the investigation results,there are los of problems,for example,the college students generally do not have adequate knowledge about environment and are unclear about the existing na- tional ecological law system; their attitude towards environment is often influenced by their majors; their evaluation of environment is far from the reality; their environmental behaviors are weakly restrained and conserved. According to these problems,related suggestions were proposed.

Niche differentiation shapes the bacterial diversity and composition of apple

Microorganisms play an important role in plant growth,health and ecological function.It is necessary to explore the microbial community because of the significant ecological and economic value of apples(Malus x domestica).However,the related bacterial communities in different ecological habitats are not clear in the unique scion/rootstock combinations of apples.In this study,the Illumina Miseq platform was used to analyze the bacterial communities in different niches(bulk soil,rhizosphere soil and roots)of two scion/rootstock combinations[Fuji/Malus xiaojinensis Cheng et Jiang(Mx)and Fuji/Malus baccata(L.)Borkh.(Mb)].The relationship between the microbial community,soil properties,and plant characters was explored.The results showed that the diversity of the bacterial community decreased from bulk soil to rhizosphere soil and then to roots.In addition,at the phylum level,Proteobacteria,Actinobacteria and Acitinobacteria were dominant and had notable divergence in different ecological niches.Distinct niches had remarkable effects on the diversity and composition of the bacterial community according to PCoA.The rootstock genotype had an effect on the bacterial composition but no effect on the diversity.pH,soil organic matter(SOM),alkaline hydrolyzable nitrogen(AN)were the main factor affecting the structure of bacterial community in rhizosphere soil,as shown by Pearson analysis.Bacteria taxa in the roots were affected by starch,fructose,sucrose and sorbitol.This study showed the microbial community structure in different ecological niches of different scion/rootstock combinations and provided some evidence for understanding the microbial-plant interaction of apple rootstocks.

Potential distribution and ecological dimensions of four species in the genus Physopelta(Hemiptera:Largidae)

Our knowledge of the identity and distribution of most species on earth is remarkably poor. Species in hotspots tend to be scarce within their range which increases their probability of extinction. In this study, we used ecological niche modeling （ENM） to estimate dimensions of realized niches of 4 species that are totally （Physopelta robusta St^l and Physopelta slanbuschii Fabricius） or partially （Physopelta cincticollis StS,1 and Physopelta quadriguttata Bergroth） distributed in the Indo-Myanmar and South Central China hotspot, and predicted additional sites where they might be found. Our findings suggest that the range of the 4 species could extend beyond their presently known distributions, which might be useful for future field surveys. Niche overlap was modeled between the 4 species, with R slanbuschii and R robusta showing more tolerance to temperature and P quadriguttata and P. slanbuschii more tolerance to precipitation. This study presents one more case study which highlights the ecological approach for taxonomic study in biodiversity conservation, especially of poorly, little known, and localized endemic species.

Study on Ecological Strategy of Enterprises' Competition

The ecolotogical research of enterprises＇ competition is the front line of current research of enterprises ＇ competition strategy ： This text applies the competition principle of living creature in ecology to research enterprises＇ competition problems .explains the ecological characterisiics of enterprises＇ competition, such as non-symmetry, crowded effect, density effect. competition-rejective effect, suitable resources niche and red queen effect etc., deduces the ecological model of enterprise＇ competition, and further analyzes enterprises＇ competition strategy; strategy R and strategy K. on the basis of enterprises＇ practices, Therefore enterprises＇ competition ecosystem theories have further been deepened and enriched.

Ecological-Genetic Studies and Conservation of Endemic <i>Quercus sideroxyla</i>(Trel.) in Central Mexico

This study examines the distribution, ecology and genetic diversity of Quercus sideroxyla Humb. Bonpl, with an emphasis on its conservation on the Natural Protected Area of Sierra Fría in North Central Mexico. Twenty-nine locations were selected, and in each location, one plot of 1500 m2 was established. At every location, we obtained an abundance of Q. sideroxyla and a basal area for each individual tree, including geographical and climatological data. We used the Outlying Mean Index (OMI) to examine whether environmental conditions had a distributional effect on Q. sideroxyla populations and to obtain the static size population structure of the species. For the genetic analysis, we collected 18 adult individuals from each population, four polymorphic loci were used to estimate genetic diversity. Q. sideroxyla abundance was associated with narrow environmental conditions, especially when considering the topographical and meteorological environmental variables. The allelic richness value was 84 alleles (21 privatealleles), and the expected mean heterozygosity was 0.855 ± 0.009. The high vulnerability of the species to changes in the land use at the local scale and to global climatic changes increases the species’ susceptibility to local disappearance.

Niche Characteristics of Herbaceous Plants under Pinus tabuliformis Plantation Forest in Feldspathic Sandstone Area

[Objectives] To explore the niche characteristics of herbaceous plants under Pinus tabuliformis plantation forest in the feldspathic sandstone area,and to provide basic data for maintaining biodiversity and community stability in the local P.tabuliformis plantation forest.[Methods] The types,quantity,average plant height,and coverage of various herbaceous plants were recorded by field survey in a well-growing P.tabulaeformis forest area.Based on the survey data,Shannon and Levins niche breadth index,Levins niche overlap index and ecological response were used to analyze the niche characteristics of herbaceous plants under P.tabulaeformis plantation forest.[Results]( i) There were 35 species of herbaceous plants in the P.tabulaeformis plantation forest in the feldspathic sandstone area.Among them,Stipa bungeiensis had the largest niche breadth indexes with better performance.Because of its strong adaptability,its community was in an obviously advantageous position.( ii) The overall niche width and niche overlap index were generally not high,and understory herb species showed differentiation.( iii) Among the understory herbaceous species,37.15% of the species were developed species,and 62.86% of the species were declining species.Among the 14 dominant species,11 were developmental species.The species with largest the resource occupancy were S.bungeiensis( 0.188 5),Heteropappus altaicus( 0.053 1),and Cleistogenes squarrosa( 0.037 9).[Conclusions] Competition among under herbaceous plants in P.tabulaeformis plantation forest in the feldspathic sandstone area was weak,and the community species had poor utilization of resources and environment.Most of the dominant herbaceous species were in the developing stage,indicating that the P.tabulaeformis plantation community tends to be relatively stable at the current stage.

Cryptosporidiosis threat under climate change in China:prediction and validation of habitat suitability and outbreak risk for human-derived Cryptosporidium based on ecological niche models

Background Cryptosporidiosis is a zoonotic intestinal infectious disease caused by Cryptosporidium spp.,and its transmission is highly influenced by climate factors.In the present study,the potential spatial distribution of Cryptosporidium in China was predicted based on ecological niche models for cryptosporidiosis epidemic risk warning and prevention and control.Methods The applicability of existing Cryptosporidium presence points in ENM analysis was investigated based on data from monitoring sites in 2011–2019.Cryptosporidium occurrence data for China and neighboring countries were extracted and used to construct the ENMs,namely Maxent,Bioclim,Domain,and Garp.Models were evaluated based on Receiver Operating Characteristic curve,Kappa,and True Skill Statistic coefficients.The best model was constructed using Cryptosporidium data and climate variables during 1986‒2010,and used to analyze the effects of climate factors on Cryptosporidium distribution.The climate variables for the period 2011‒2100 were projected to the simulation results to predict the ecological adaptability and potential distribution of Cryptosporidium in future in China.Results The Maxent model(AUC=0.95,maximum Kappa=0.91,maximum TSS=1.00)fit better than the other three models and was thus considered the best ENM for predicting Cryptosporidium habitat suitability.The major suitable habitats for human-derived Cryptosporidium in China were located in some high-population density areas,especially in the middle and lower reaches of the Yangtze River,the lower reaches of the Yellow River,and the Huai and the Pearl River Basins(cloglog value of habitat suitability>0.9).Under future climate change,non-suitable habitats for Cryptosporidium will shrink,while highly suitable habitats will expand significantly(χ^(2)=76.641,P<0.01;χ^(2)=86.836,P<0.01),and the main changes will likely be concentrated in the northeastern,southwestern,and northwestern regions.Conclusions The Maxent model is applicable in prediction of Cryptosporidium habitat suitability and can achieve excellent simulation results.These results suggest a current high risk of transmission and significant pressure for cryptosporidiosis prevention and control in China.Against a future climate change background,Cryptosporidium may gain more suitable habitats within China.Constructing a national surveillance network could facilitate further elucidation of the epidemiological trends and transmission patterns of cryptosporidiosis,and mitigate the associated epidemic and outbreak risks.

我国先进制造业与生产性服务业融合生态位研究

基于2012-2021年省级面板数据,运用生态位模型测度先进制造业与生产性服务业融合差异与竞争现状。结果表明:先进制造业与生产性服务业融合生态位宽度空间上呈现东高西低分布特征,其中融合基础生态位宽度两极分化极其严重是导致我国生态位宽度呈梯度分布的主要原因。生态位重叠现象普遍,区域间存在激烈竞争,其中地理位置和优势主导产业相近更易形成相同的融合路线,导致重叠度较高。生态位适宜度整体水平偏低,融合子系统生态位适宜度均呈现“东高、中平、西低”特征。

甘南高寒草甸退化对植物功能群物种多样性与物种多度分布的影响

【目的】探究甘南高寒草甸植物功能群多样性及其物种多度分布对退化的响应,分析随退化程度的加深不同植物功能群的群落构建机理及资源利用方式。【方法】研究以甘南高寒草甸为对象,采用样地调查法收集数据,使用物种多度模型对其进行拟合分析,并采用双向聚类分析对群落物种进行分类。【结果】随着退化程度的加深,植被优势种以禾本科和莎草科植物为主,逐渐变为杂类草功能群植物为主,杂类草功能群在群落多样性分布中起主导作用;全部物种多度分布随着退化程度的加深发生变化,其中,无退化草甸的最优拟合模型是VOLKOV,轻度退化草甸的最优拟合模型是GEO,中度退化草甸和重度退化草甸的最优拟合模型为BRO,资源分配模式由随机分配转向固定分配的分配模式;禾草功能群的最优拟合模型以生态位模型为主,资源分配方式由固定分配和随机分配共同主导,豆科功能群的最优拟合模型是BRO,资源分配方式以固定分配为主,杂类草功能群的最优拟合模型从中性模型向生态位模型转变,与全部物种多度分布的最优模型基本一致,且资源分配由随机分配向固定分配转变。【结论】杂类草功能群是影响群落物种多度分布的主要原因,但是禾草和豆科功能群的贡献也不可忽视。