Species Diversity Of Plant Communities Research Articles

Productivity and Species Diversity of Plant Communities Are Higher inside than outside the West Ordos National Nature Reserve, Northern China.

Nature reserves play an important role in the protection of biological habitats and the maintenance of biodiversity, but the performance and mechanisms of desert steppe nature reserves in improving plant community productivity, biodiversity and soil nutrient content are still largely unknown. To investigate the conservation effects of desert steppe nature reserve management on plant productivity and biodiversity, we compared the plant biomass, diversity and soil nutrient content inside and outside the West Ordos National Nature Reserve through sample survey, biomass determination, diversity index calculation and soil nutrient content determination. We found the following: (1) The aboveground biomass and belowground biomass of plant communities in the nature reserve were significantly larger than those outside the reserve; and the aboveground biomass of plant communities in shrub-steppe was significantly larger than that of herb grassland in both the nature reserve and the outside of the reserve. (2) The Margalef richness index, Shannon-Wiener index and Simpson index were significantly greater in the reserve than outside the nature reserve. In the desert steppe, the establishment of the nature reserve increased the α-diversity of the plant community. (3) The soil organic carbon (SOC) and soil total nitrogen (STN) were greater in the nature reserve than outside the reserve, and for the 10-20 cm and 20-40 cm soil layers, the SOC and STN were significantly greater in the core protected zone of the reserve than outside the reserve. The reserve significantly increased the nutrient content of the deeper soil layers. (4) The aboveground biomass of the plant community had a significant positive linear relationship with the species richness index, the Shannon index, and the Simpson index. There was a positive correlation between the diversity of the plant community and the soil nutrients. In summary, the nature reserve improved local plant productivity, biodiversity and the soil nutrient content, and the soil nutrient content in deeper soil layers may be the driving factor for the increase in productivity and biodiversity, which deepens our understanding of the conservation effectiveness of the nature reserve and its mechanisms.

Modern plant fodder resources of the steppes and meadows of the ancient Chir landscape of the “Tsimlyansky” nature reserve

In 2022, studies of the species diversity of plant communities, their aboveground mass and the resource-feeding potential of various types of steppes and meadows in the “Tsimlyansky” nature reserve were conducted. The method of vegetation cover mowing (n = 29) in seven types of steppes and meadows determined the aboveground mass of 101 species of herbaceous plants within the ancient Chir landscape of the Don-Tsimlyansk sand massif. The species richness of plant communities varies between (5.7±1.7) – (14.0±1.2) species/0.25 m2 and averages 10.1±1.0 species/0.25 m2. The average share of cereal species in the communities is 23%, and grasses are almost 3 times more – 64%. The total aboveground biomass in 7 types of steppes and meadows varies between (197.4±25.6) – (379.1±92.5) g/m2. The accumulated mort (necro) mass is (152.2±12.5) – (411.9±43.9) g/m2.

The Dynamics of Sugar Maize (Zea mays saccharata Sturt.) Infestation of Field Pansy (Viola arvensis).

Field pansy infestation can lead to a decrease in the species diversity of plant communities and to the disappearance of other species. Field pansy infestation is fairly common in many crops, including maize. Understanding the ecology and management strategies for field pansy in maize is essential for effective weed control. This research into sugar maize was conducted from 1992 to 2019 in the Research and Education Center Gorzyń, Złotniki branch, which belongs to the Poznań University of Life Sciences. The assessment of weed infestation was carried out in experiments that focused on chemical weed control in maize. The experiments were established as single-factor randomized block designs with four field replications. The aim of the study was to evaluate dynamic changes in the status and the degree of field pansy infestation in sugar maize that was cultivated after various other crops in the Wielkopolska region, with a focus on weather conditions. The results indicated that the probability of field pansy individuals occurring among the total number of weeds was highest when maize was cultivated after wheat, but the probability of such infestation did not significantly differ when maize was sown in a crop rotation after winter triticale.

Increased soil penetration resistance drives degrees of hemeroby in vegetation of urban parks

Urban parks provide a variety of ecosystem services, and a range of management practices promote their maximisation. The species diversity of plant communities is a factor in the maintenance of ecosystem services. The reconstruction of parks is one of the management practices, but the environmental impact of such activities is not clear. The reconstruction of parks affects vegetation and soil cover, and the interconnection of these components of the urban park ecosystem has not been studied before. The study revealed the features of variability of physical properties of soil and vegetation cover and identified their interconnection in the conditions of urban park reconstruction. The study was conducted in the recreational area of the Botanical Garden of Oles Honchar Dnipro National University (Ukraine). The park was studied in the area where reconstruction activities had previously been carried out. During the reconstruction process, walkways were restored, shrubs were removed, old or damaged trees were excavated, and tree crowns were trimmed. Young trees were planted in place of the removed old trees. Old outbuildings that significantly impaired the aesthetic impression of the park were also dismantled. The reconstruction involved transport and construction equipment. Samples were collected within transects, two of which were located in the reconstruction area, and two other transects were located in a similar area of the park where no reconstruction was carried out. The plant community was found to consist of 65 species. The mean level of alpha diversity was 11.5 species and beta diversity was 5.7. The alpha diversity was higher in the reconstructed park. The principal component analysis of the variability of soil properties extracted four principal components with eigenvalues greater than one. The principal components 1 and 3 reflect the variability of soil properties induced by the park's reconstruction, while the principal components 2 and 4 reflect variability that may be caused by other anthropogenic factors unrelated to the park's reconstruction, or may be due to natural variability of the soil cover. The principal component 1 indicates a uniform increase in the soil penetration resistance as a result of the application of technological processes during the reconstruction. This effect may be the result of the direct technological impact of the mechanisms employed and the large number of employees involved in the park's reconstruction. The condition of the crown space of the park plantation can explain the variation in soil penetration resistance. The increase in the height and projective cover of the grass vegetation is due to a decrease in the closure of the stand crowns, but the effect of such coordinated stand and grass dynamics on soil penetration resistance is observed only at a depth of 25–55 cm. This effect can be explained by the influence of the plant root system on the physical state of the soil. The root system of herbaceous plants is capable of loosening the soil and reducing its soil penetration resistance. The reconstruction of the park led to an increase in the hemeroby of the plant community. The criterion for the success of the reconstruction may be an increase in the attractiveness of the park for visitors without the risk of increasing hemeroby. The trend of increasing hemeroby clearly coincides with the direction of transformation of soil conditions, which are indicated by the principal component 1. The increase in the soil penetration resistance is a driver of the growth of vegetation cover hemeroby. The physical environment of the soil cover acts as an important environmental filter that affects the structure of the vegetation cover and the species composition of plant species complexes.

A study of plant community diversity based on quantitative analysis model and prediction model

Plant community species diversity is the pivot that connects ecosystem multi functionality and environmental change. In order to explore the influence of community species number on drought adaptation, this paper uses logistic fitting and residual verification formed by grayscale accumulation to obtain the population dynamics change curve under ideal conditions, followed by selecting indicators such as soil moisture amount and plant growth rate, and establishing a prediction model based on the plant growth pattern of plant communities under different weather cycles and the interaction mechanism between different species, and The conclusions were drawn, which provided a theoretical basis of the subsequent research on the population size under drought conditions.

Effects of Changing Restoration Years on Soil Nutrient Traits and Plant Community Diversity in a Phosphate Mining Area

The thinning vegetation and soil erosion problems left behind by extractive mining have caused serious environmental pollution, and vegetation restoration is one of the effective strategies to counter them. To study the effects of vegetation restoration on plant community species diversity, soil carbon, nitrogen and phosphorus, and the response of their plant community succession, four communities of different ages (1, 7, 10, 40) and one natural forest (>50 years) in the Kunyang phosphate mine were selected, and the analysis was carried out using the methods and protocols for plant community inventory. The species composition was recorded, and soil was collected from 0–60 cm in each community to determine the response of soil nutrients and plant diversity to the restoration process. The results show that the species richness of the community increases with the restoration year, the species composition at 40 years of restoration is similar to that of the natural forest, and the Shannon–Wiener diversity index in the tree layer at 40 years of restoration is greater than in the natural forest. Soil pH showed a decreasing trend with restoration year, and TP and AP increased with increasing time series. And the linear stepwise regression analysis showed that soil pH, soil organic carbon (SOC), total phosphorous (TP), available phosphorous (AP), and restoration year were the main factors of plant diversity. Compared to restoration of 10 years, TP and AP at the restoration of 40 years increased to 11.9–20.0 g∙kg−1 and 33.4–75.5 mg∙kg−1. The SOC of the community reached a maximum at 40 years of restoration, 1.5, 2.8, and 2.4 times higher at 0–20 cm, 20–40, and 40–60 cm, respectively, than at 1 year. The organic carbon fraction increased with the restoration year in an ‘N’ pattern, and mineral-associated organic carbon (MOC) and unstable organic carbon fraction decreased at 10 years and 40 years of restoration. The SOC of natural forests decreased, but stable organic carbon increased. The soil pH, SOC, and organic carbon fraction of the communities decreased with increasing soil depth, while TP and AP increased with increasing soil depth at the later period of restoration. In general, with extended restoration years, 40 years plant of restoration in phosphate mines can be expected to allow for plant community succession to climax community, and the key influence on plant diversity are the phosphorus and stable carbon fractions. These results are expected to facilitate the future basis for vegetation succession and restore systems during mining area restoration.

Diversity of lithophytic moss species in karst regions in response to elevation gradients.

The distribution pattern of species diversity along various elevation gradients reflects the biological and ecological characteristics of species, distribution status and adaptability to the environment. Altitude, a comprehensive ecological factor, affects the spatial distribution of species diversity in plant communities by causing integrated changes in light, temperature, water and soil factors. In Guiyang City, we studied the species diversity of lithophytic mosses and the relationships between species and environmental factors. The results showed that: (1) There were 52 species of bryophytes in 26 genera and 13 families within the study area. The dominant families were Brachytheciaceae, Hypnaceae and Thuidiaceae. The dominant genera were Brachythecium, Hypnum, Eurhynchium, Thuidium, Anomodon and Plagiomnium; The dominant species were Eurohypnum leptothallum, Brachythecium salebrosum, Brachythecium pendulum etc. The number of family species and dominant family genera increased first and then decreased with the increase of altitude, and their distribution in elevation gradient III (1334-1515m) was the largest, with 8 families, 13 genera and 21 species. The elevation gradient I (970-1151m) was the least species distributed, with 5 families, 10 genera and 14 species. The dominant species with the largest number in each elevational gradient were Eurohypnum leptothallum, Brachythecium pendulum, Brachythecium salebrosum and Entodon prorepens; (2) There were five kinds of life forms in different elevation gradients, including Wefts, Turfs, Mat, Pendants and Tail. Among them, wefts and turfs appeared in all elevations, while a small amount of Pendants appeared in the area of elevational gradient I (970-1151m), and the most abundant life form was found in the range of elevational gradient III (1334-1515m); (3) Patrick richness index and Shannon-Wiener diversity index were highly significantly (p<0.01) positively correlated, both of which increased and then decreased with elevation, reaching a maximum at elevation gradient III (1334-1515m); The Simpson dominance index had a highly significant (p<0.01) negative correlation with the Patrick richness index and the Shannon-Wiener diversity index, which showed a decreasing and then increasing trend with increasing altitude; Pielou evenness index showed no discernible trend; (4) β diversity study revealed that while the similarity coefficient tended to decrease with increasing altitude, the species composition of bryophytes increased. The elevation gradient II (1151-1332m) and elevation gradient I (970-1151m) shared the most similarities, whereas elevation gradient III (1515-1694m) and elevation gradient I shared the least similarities (970-1151m). The findings can enrich the theory of the distribution pattern of lithophytic moss species diversity at distinct elevation gradients in karst regions, and serve a scientific and reasonable reference for restoring rocky desertification and protecting biodiversity there.

Source apportionment of heavy metals and their effects on the species diversity of plant communities in the Caizi Lake wetland, China.

This study investigated the effects of heavy metals on the species diversity of the Xinjian Dyke Wetland, an ecosystem where reclaimed farmlands are being transformed back into wetlands through the introduction of indigenous plants. The sources of soil heavy metals were analyzed, and correlation analyses were conducted to assess the relationships between heavy metal content and biodiversity indices. The results indicated that (1) the mean contents of Hg, Cd, Cu, Zn, As, Cr, and Pb were higher than the control values, with the content of Hg, Cd, Cu, and Zn exceeding the national standard; (2) the soil heavy metals mainly came from pesticides, chemical fertilizer, transportation, sewage irrigation, and the soil matrix; and (3) Hg and As were not significantly correlated with the diversity indices, but there was a highly positive correlation for Cu, Cr, and Pb, and a significant negative correlation for Zn and Cd. Collectively, our findings indicated that heavy metals have different effects on the plant species diversity inXinjian Dyke reconstruction area. The ecological restoration of wetlands from reclaimed farmlands should reasonably increase tolerant species and maximize the ecological niche differentiation of the species. Moreover, functionally redundant species should not be planted.

Vegetation–soil dynamics in an alpine desert ecosystem of the Qinghai Lake watershed, northeastern Qinghai–Tibet Plateau

Different types of dunes cause habitat differences, which can affect vegetation growth. In turn, water utilized by vegetation leads to the differential distribution of soil moisture in different dunes. However, vegetation–soil dynamics in the alpine desert of the Qinghai–Tibet Plateau remain poorly understood. We chose the largest section of desert along the eastern shore of Qinghai Lake as a study area to test the hypotheses that plant community characteristics and soil physicochemical properties show differences in different sand-binding communities, in addition to soil moisture content, based on methods of field investigations and in situ observations. The main results were as follows:1) Plant community species diversity and herb coverage increased with the stabilization status of dunes; meanwhile, coverage increased with the age of the added artificial semi-fixed dunes. 2) Surface deposits were mainly composed of medium sand, leading to low organic matter and nutrient content in the study area; this being different from other deserts in northern China. 3) Soil moisture’s seasonal variation was consistent with rainfall seasonality and lacked significant interannual differences, while its vertical distribution was influenced by precipitation infiltration. 4) Soil crust forms beneath specific species, such as leguminous plants in the study area, which should be effective at preventing wind erosion. Our findings will facilitate a mechanistic understanding of plant–soil–water relationships in alpine deserts and provide timely information for screening introduced species for enhancing sand-fixation effectiveness.

Competition model explains trends of long-term fertilization in plant communities.

Over 40 years ago, Kempton (Biometrics, 35, 1979, 307) reported significant modification to plant community structure following a long-term fertilization experiment. Many researchers have investigated this phenomenon in the years since. Collectively, these studies have shown consistent shifts in rank abundance relationships among species in communities following fertilization. The previous studies indicated that fertilization affects community structure through several critical processes, including trait-based functional response, reordering of species in rank abundance diagram (RAD), and niche dimensionality, although some questions have remained. How does the species reordering driven by the plant responses cause characteristic trends in temporal changes of RAD? Why are those trends ubiquitous in various systems? To answer those questions, we theoretically investigated the effects of fertilization on community structure based on a colonization model (or Levins model) with competition-fecundity trade-offs, which can result in the coexistence of multiple species under competition. The model represents characteristic RAD, which can be an adequate tool to study community composition. Our theoretical model comprehensively represents observed trends in rank abundance relationships following long-term fertilization and suggests that competitive interactions among species are a critical factor in structuring species diversity in plant communities.

α Diversity of Desert Shrub Communities and Its Relationship with Climatic Factors in Xinjiang

In the past 30 years, Northwest China has experienced a warm and humid climate increase trend. How this climate change will affect the species diversity of plant communities is a hot issue in ecological research. In this study, four α diversity indexes were applied in 29 shrub communities at desert sites in Xinjiang, including the Margalef index, Simpson index, Shannon–Wiener index, and Pielou index, to explore the relationship between the α diversity of the desert shrub communities and climate factors (mean annual temperature (MAT) and mean annual precipitation (MAP)). The species diversity indexes varied across these different desert shrub communities. Tamarix ramosissima communities had the highest Margalef index, while the Krascheninnikovia ewersmannia communities had the lowest Margalef index; T. ramosissima communities also showed the highest Simpson index and Shannon–Wiener index, but Alhagi sparsifolia communities showed the lowest Simpson index and Shannon–Wiener index. The Ephedra przewalskii communities and Karelinia caspica communities showed the highest and the lowest Pielou index, respectively. The α diversity indexes (except the Pielou index) of desert shrub communities had a significantly positive correlation with MAP (p &lt; 0.05) but a non-significantly correlation with MAT (p &gt; 0.05). These results indicate that, compared with temperature, water conditions are still a more vital climatic factor affecting the species diversity of desert shrub communities in Xinjiang, and thus, the recent “warm and humid” climate trend in Xinjiang affects the α diversity of desert shrub communities.

Response of Plant Species Diversity to Flood Irrigation in the Tarim River Basin, Northwest China

This study quantitatively analyzes the effects of flooding on the growth and species diversity of riparian forests along the Yarkant River and the Tarim River, Xinjiang, in northwest China, and provides important information for the efficient utilization of water and water resource management in arid regions. Monitoring of species diversity of riparian forests was conducted every year from 2016 to 2019 in the Xiamale forest district in the lower reaches of the Yarkant River, and in the Shaya forest district and the lunnan forest district in the upper and middle reaches of the Tarim River. The Pielou index, Shannon–Wiener index, Simpson index, and importance value were used to analyze the influence of flooding. The results showed the following: (1) After three years of flooding, indices for the lower reaches of the Yarkant River and Tarim River were significantly increased and 11 new plant species appeared. (2) With increasing distance from the river channel, plant density and species diversity decreased. Flooding trends are the main factors affecting the distribution of plant species and water is the main restricting factor that influences plant growth in arid areas; thus, desert riparian forests improved significantly after flooding. (3) Flooding increases the regeneration capacity and species diversity of plant communities in desert riparian forests. In order to maintain the current trend of ecological improvement, flooding irrigation must continue.

Postagrogenic phytocenoses of the Volga‐Oka interfluve, Russia

Aim. On the basis of factual material, an assessment was made of the state of land previously (more than 15 years ago) developed as arable land and "abandoned" to date.Material and Methods. Control plots located in different landscape provinces of the Volga‐Oka interfluve were compared in terms of the state of the vegetation cover, as well as the type of overgrowth.Results. Three types of overgrowing of postagrogenic lands characteristic of the initial and intermediate stages of overgrowing of pre‐climax communities have been identified: overgrowing of fields associated with a change in land use; overgrowing of fields with a nearby forest; and overgrowing of fields without a closely located forest.Conclusion. It was shown that as a result of the overgrowing of agricultural lands, the species diversity of plant communities is sharply reduced, the restoration of which is very problematic in the foreseeable future. While postagrogenic phytocenoses are able to gradually restore their production potential to the level of natural phytocenoses, however, their productivity will occur with a different species composition of herbaceous plants with low biodiversity.

STRUCTURAL AND SPECIES DIVERSITY ON NORTH AND SOUTH SLOPES IN CONIFEROUS-DECIDUOUS FORESTS OF THE NORTH-WESTERN CAUCASUS

The research was conducted in similar soil-orographic conditions of three widespread coniferous-deciduous forest types in the North-Western Caucasus: aspen-hornbeam, beech-fir-hornbeam, and fir-beech. The methods used included geobotanical, population-ontogenetic, and soil-zoological. It was found that the north and south slopes in all the studied forest types, in comparison with the flat areas, are characterised by significantly higher plant species richness. The efficiency of the renewal of arboral cenopopulations was much higher on the slopes, in comparison with the flat areas: the number of tree species (higher by 20–70%); density of tree species (higher by 50–100%); the number of cenopopulations of tree species with a complete ontogenetic spectrum was larger on the slopes, in comparison with the flat areas. A greater number of ecological groups of plants were described on the north and south slopes, in comparison with the flat areas. The proportion of boreal species was higher on the north slopes, in comparison with the south slopes, whereas the majority of meadow-forest edge species were the south slopes. The north and south slopes were characterised by the full functional diversity of soil invertebrates, whereas endemic and sub-endemic macrofauna also preserved. On the north slopes, we revealed a high biomass of large litter and soil saprophages, including species and groups actively participating in transformation of plant litter and soil formation. The south slopes showed high densities of phytophages and predators (among soil macrofauna), which regulate the diversity of other components of forest communities through biotic interactions. All the studied forest types on the north and south slopes exceeded the flat areas in terms of species diversity of plant communities, regeneration of tree species, ecological plant groups, endemic fauna of soil invertebrates, including soil formers. 

Correlation between Vegetation Structure and Species Diversity in Traditional Villages in Karst Topographic Regions of the Zunyi City, China.

Studying the relationship between vegetation structure and diversity is important in an area having karst topography and unique traditional customs. We selected a total of six traditional villages in Zunyi City, China, to collect vegetation data. Additionally, using one-way ANOVA and the Pearson correlation coefficient analytic method to analyze, the results showed that, overall, plant communities were mostly regularly distributed. The overall differentiation degree was low aggregation, intensity, and the extreme intensity mixed state. Overall, competitive pressure, growth vigor and stability were better than the natural forest. The community stability index at lower altitude was significantly higher than that at higher altitude. The recorded plant communities in the living space were typically aggregated, the plant communities were randomly distributed in the production space, and the plant communities were uniformly distributed in the ecological space. In general, the diversity indexes, except the Jh index, were the highest in the herb layer; the second was in the shrub layer and the lowest was in the tree layer. Species diversity at the middle altitude was higher than that at low and high altitudes (except for the shrub at a high altitude of 1100-1160 m). The overall plant species diversity was highest in the living space, second highest in the ecological space and lowest in the production space. On the whole, there was a significant correlation between the spatial structure of plant communities and the species diversity of plant communities at different altitudes, and in PLE spaces. The main objective of this study was to reveal the plant community structure, species diversity, and their relationship under the dual effects of national traditional culture and karst landform. Additionally, we sought to provide theoretical guidance for the construction of plant community protection and biodiversity conservation in traditional villages in karst areas.

Study on space diversity and influencing factors of Tunpu settlement in central Guizhou Province of China

The Tunpu settlements are the historical product of the co-evolution development of the unique geographical and cultural environment of Guizhou and the military defense policies of Ming Dynasty (1368–1644 AD), which created products such as the station troops and station farms. In this study, taking 10 Tunpu settlements in central Guizhou as the research objects, the space diversity of the Tunpu settlement and its influencing factors were analyzed based on the theory and calculation method of plant community species diversity. The results showed that: (1) On the whole, the space α-diversities of the military Tunpu settlements and the commercial Tunpu settlements were relatively high, with strong spatial similarity, while the residential Tunpu settlements had a lower degree of space α-diversity and significant difference. The space α-diversity of different types of the Tunpu settlement presents a variety of changes from the core protected areas to coordinated control areas. (2) There was a significant correlation between the spatial network and spatial morphological indicators and space β-diversity among the Tunpu settlement, and the stepwise regression showed that spatial morphological indicators had a strong explanatory power for the space β-diversity among the Tunpu settlements. (3) The space diversities of the Tunpu settlements were affected by the multiple synergies of natural environment, policy support, social-economic factors and cultural customs. Among them, policy factors and cultural factors were the dominant factors in the space diversity characteristics of the Tunpu settlements. By analyzing the space diversity law and its driving factors of the Tunpu settlements, this study could provide an important scientific basis for the protection planning and management of traditional settlements.

三峡水库涪陵-奉节段消落带优势草本植物生态位与种间联结性研究

PDF HTML阅读 XML下载 导出引用 引用提醒 三峡水库涪陵-奉节段消落带优势草本植物生态位与种间联结性研究 DOI: 10.5846/stxb202011162953 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学青年基金面上项目（31270451）；三峡库区水环境演变与污染防治重点实验室开放基金项目（WETKL2012MS-07）；国家自然科学青年基金（41902024）；重庆市科委面上项目（cstc2019jcyj-msxmX0656） Niche and interspecific association of dominant herbaceous plants in the water-level-fluctuating zone of Fuling-Fengjie section of the Three Gorges Reservoir Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:参照相邻格子法对三峡水库中段（重庆市涪陵-奉节段消落带）地上植被进行调查，并运用生态位宽度、生态位重叠度、χ2检验等手段对优势草本植物生态位与种间联结性进行分析，能在一定程度上揭示三峡水库消落带优势草本植物的生态学特性、进而推测植被群落的演替趋势，以期为三峡水库消落带植被生态修复提供理论基础或参考建议。结果表明：（1）本次调查发现共有优势植物57种、隶属22科44属，其中狗牙根的生态位宽度最大、占绝对竞争优势。（2）在105个种对中，生态位相似比（Cih）≥0.50的种对有4个，生态位重叠值（Lih）≥0.50的种对有7个，种间相似性较小、竞争关系较弱。（3）χ2检验结果显示，优势植物种间正负联结比为1.33，正联结优势不明显；而Pearson与Spearman秩相关检验结果显示，种间正负联结比分别为0.54、0.75，负联结占优势。三种检验方式均表明，优势植物种间联结性较弱、稳定性相对较差、独立性相对较强。（4）种间联结系数（AC）≥0.60的种对数为7种，共同出现百分率（PC）≥0.7的种对数仅为1种。种间总体正联结性不强，物种趋于独立分布。（5）种间Pearson、Spearman秩相关检验与相应的Cih和Lih之间均呈显著正相关，表明种间正（负）关联越强、Cih和Lih越大（小）。（6）本文研究结果在一定程度上反映了三峡水库消落带植被退化生态系统现状，为最大程度提高消落带植物群落结构稳定性和物种多样性，针对小流域植被恢复与重建有如下参考建议：在整体上，可以采用以狗牙根（Cynodon dactylon（Linn.） Pers）、苍耳（Xanthium sibiricum）、鬼针草（Bidens pilosa L.）等为先锋植物，以狗尾草（Setaria viridis）、稗（Echinochloa crusgalli）、牛鞭草（Hemarthria altissima）等为伴生种的群落配置模式进行宏观布局；在局部上，可以采用稗（Echinochloa crusgalli）+苘麻（Abutilon theophrasti Medicus）、狗尾草（Setaria viridis）+黄花草木樨（Melilotus officinalis L.）、马唐（Digitaria sanguinalis）+水蓼（Polygonum hydropiper L.）等种对配置模式进行实地配置。 Abstract:This article refers to the adjacent grid method to investigate the aboveground vegetation in the middle section of the Three Gorges Reservoir (Fuling-Fengjie section of Chongqing City). We use niche width, niche overlap, χ2 test and other methods to compare the niche of dominant herbaceous plants, which could reveal the ecological characteristics of dominant herbaceous plants in the Three Gorges Reservoir water level fluctuating zone to a certain extent. Then, we infer the succession trend of plant community, so as to provide theoretical basis or reference suggestions for the ecological restoration of vegetation in the Three Gorges Reservoir water level fluctuating zone. The results showed that:(1) There were 57 plant species belonging to 22 families and 44 genera. The niche breadth of bermudagrass was the largest and occupied the absolute competitive advantage. (2) Among the 105 dominant plant species pairs studied, there were 4 species pairs with niche similarity ratio (Cih) ≥ 0.50 and 7 species pairs with niche overlap value (Lih) ≥ 0.50, indicating that the similarity between species was small and the competition was weak. (3) χ2 test results showed that the positive and negative association ratio of dominant plants was 1.33, indicating that the positive association advantage was not obvious. Pearson and Spearman rank correlation test showed that the positive and negative association ratio was 0.54 and 0.75, respectively, indicating that negative association was dominant. All the three tests showed that the interspecific association of dominant plants was weak, the stability was relatively poor and the independence was relatively strong. (4) The number of species with interspecific association coefficient (AC) ≥ 0.60 was 7 and the number of species with cooccurrence percentage (PC) ≥ 0.7 was only 1, indicating that the positive association between species was not strong and species tended to be independent. (5) Pearson and Spearman rank correlation tests showed a significantly positive correlation with Cih and Lih between species, indicating that the stronger the positive (negative) correlation, the greater the Cih and Lih. (6) In order to maximize the structural stability and species diversity of plant community in the Three Gorges Reservoir water-level-fluctuating zone, the following suggestions were put forward for vegetation restoration and reconstruction in small watershed:on the whole, a community configuration mode with Bermudagrass, Cocklebur, Bidens, etc. as the dominant plants, and Setaria, Barnyardgrass, and Virginia etc. as the companion species could be used for macro layout. In the local, the configuration mode of Echinochloa crusgalli+Abutilon bicolor, Setaria setifolia+Melilotus lutea, Digitaria tangutorum+Polygonum hydropiper etc. could be used for field configuration. 参考文献 相似文献 引证文献

三江源区高寒坡地退化植物群落多样性和地上生物量沿海拔梯度的变化特征

PDF HTML阅读 XML下载 导出引用 引用提醒 三江源区高寒坡地退化植物群落多样性和地上生物量沿海拔梯度的变化特征 DOI: 10.5846/stxb202104221056 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 青海省三江源二期工程科研项目(2019-S-1-1);国家自然基金项目(31870433,41671508);第二次青藏高原综合科学考察研究项目(2019QZKK0302) Variation characteristics of plant community diversity and above-ground biomass in alpine degraded slopes along altitude gradients in the headwaters region of three-river on Tibetan plateau Author: Affiliation: Fund Project: This study was supported by the Qinghai Province Sanjiangyuan Phase II Project Scientific Research Project (2019-S-1-1)and the Natural Science Foundation of China (31870433,41671508）and the Second Tibetan Plateau Expedition?(2019QZKK0302) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:山地生态系统退化对生物多样性和地上生物量,以及相互关系在海拔高度梯度上的格局影响,是认识全球变化和人类干扰引起自然生态系统变化的重要内容。以青藏高原三江源区高寒坡地退化草甸和灌丛为研究对象,探讨退化草甸、灌丛群落物种多样性与地上生物量关系及其沿海拔梯度的变化规律。结果表明:(1)坡地退化的上坡位植被盖度显著大于下坡位(P＜0.05)。坡地退化高寒草甸和高寒灌丛,植物物种多样性沿海拔梯度变化规律一致,均呈现"单峰"分布格局。坡地退化高寒草甸Shannon-wiener指数和Simpson指数二次回归方程解释度达到80%和70%以上(P＜0.05)。(2)坡地退化高寒草甸和高寒灌丛的地上生物量与海拔梯度的变化规律一致,即随海拔升高高寒坡地地上生物量呈先增加后降低的变化趋势。海拔梯度对退化高寒山地地上生物量的解释度达到85%以上(P＜0.05)。(3)物种多样性和地上生物量的关系在两个坡地上表现出一致的规律,呈线性增加的变化趋势。高寒草甸坡地回归方程解释度达到70%,高寒灌丛坡地达到60%(P＜0.05)。坡地退化高寒灌丛植物群落多样性和地上生物量高于高寒草甸植物群落。高寒坡地退化草甸和灌丛植物群落物种多样性以及其与地上生物量之间的关系沿海拔梯度的变化规律一致,海拔梯度造成的环境差异对植物群落物种多样性和地上生物量影响仍较大。该研究对认识三江源区退化山地形成生态学机制,及提出有效的生态恢复措施具有重要参考价值。 Abstract:The impact of alpine ecosystem degradation to biodiversity and aboveground biomass and the two interaction patterns along with the gradient of elevation are critical for understanding the changes in natural ecosystems that induced by global climate change and human disturbance. This research focused on the degraded meadow and shrub of hillside in the headwaters region of three-river on Tibetan plateau and aimed to investigate their relationship between plant species diversity and above-ground biomass along an elevation gradient. We observed that: (1) the vegetation coverage on the upslope of degraded sloping alpine meadows and alpine shrubs was significantly greater than that on the downslope (P＜0.05). Both degraded slopes of alpine meadows and alpine shrubs exhibited a unimodal pattern of plant species diversity over elevation gradients. Furthermore, the interpretation rate of the quadratic regression equations of the Shannon-wiener index and the Simpson index against elevation gradients on alpine meadow slopes achieved more than 80% and 70%, respectively (P＜0.05). (2) The above-ground biomass of degraded sloping alpine meadows and alpine shrubs was consistent with the altitude gradient, that is, the above-ground biomass of alpine meadows and alpine shrubs increased initially then declined with the increase of altitude. Interpretation rate of the quadratic regression equation indicated that the altitude gradient could accounted for more than 85% of the above-ground biomass in degraded alpine meadows and alpine shrubs (P＜0.05). (3) The association between plant species diversity and above-ground biomass exhibited a similar pattern on both alpine meadows and alpine shrubs slopes, which proved to be a linear increasing trend. The interpretation rate of the regression between plant species diversity and above-ground biomass reached more than 70% on alpine meadow slopes and more than 60% on alpine shrub slopes (P＜0.05). Also, the alpine shrubs on degraded slope land had higher plant community diversity and above-ground biomass than alpine meadow plant communities. The species diversity of plants in degraded alpine, alpine meadows, and alpine shrub slopes, as well as their relation with above-ground biomass, was consistent with the pattern of changes along elevation gradients in degraded alpine mountains. These findings suggest that environmental variations induced by altitude gradients continue to have a stronger influence on plant community species diversity and above-ground biomass. This study has important reference value for understanding the formation ecological mechanism of degraded alpine meadow and shrub of hillside in the headwaters region of three-river on Tibetan plateau and putting forward effective ecological restoration measures. 参考文献 相似文献 引证文献

Исследование и оценка состояния территорий Волгоградского Заволжья, представляющих особую ценность для сохранения объектов животного и растительного мира региона

This paper presents the results of monitoring the current state of natural complexes and rarespecies of plants and animals in the special protection natural areas (SPNA) to conserve fauna and flora, listed in the Red Book of Volgograd Oblast. Bykovo municipal district of Volgograd region – “Tazhinsky estuary” and “Prishibo-Mogutinskaya system of estuaries” were selected as the object of the study. The initial materials of the study were the data obtained during field studies carried out from May to September 2021. The main purpose of the study has two components: an analysis of the current situation (the current status and number of rare species and natural complexes in general and in the area near the protected area (not more than 1 km) according to the study results) and identification of limiting factors and threats to each species and the natural complexes as a whole. The main methods used during the expeditions were continuous records of all vertebrates on long, multi-day automobile and hiking trails. At the same time, we searched for nests and breeding territories of birds in specific habitats and interviewed local people to identify habitats of large birds of prey and other rare species of birds. All rare species encounters were positioned with a Garmin Etrex 30x GPS receiver. Traditional geobotanical methods (ecologicalphytocenotic and ecological-floristic analysis of phytocenoses) and quantitative methods (analysis of the species composition of phytocenoses by pairwise conjugation and analysis of floristic and phytocenotic similarity of phytocenoses), and the main sample-area method were applied during the study to study the species diversity of plant communities. The results and digital mapping of the results of field studies have shown that the areas of special value for the conservation of fauna and flora listed in the Red Book of Volgograd region – “Tazhinskyestuary” and “Prishibo-Mogutinskaya estuary system” irreversibly degrade due to changes in the hydrological regime. These reclaimed estuaries have been very poorly filled with water in recent years, and in some years, have remained fully dry (this has been the case for the past two years). This leads to the progressive salinization of soils and the extinction of rare species for which these SPNAs were organized. Recommendations on possible changes in the regime of special protection, boundaries, and SPNA category were developed based on the analysis of the studies’ results. The additional survey of estuaries in late April-early May in a year with good moisture is required to decide on the future of SPNA.

Plant Species Diversity of Plant Communities and Heavy Metal Accumulation in Buffer Zone of Momianhe Stream Along a Long-Term Mine Wastes Area, China.

The species composition of eight shrub communities were investigated in order to understand the species diversity of plant communities in buffer zone and wetland of Momianhe stream along a long-term mine waste area, Lanping county, Yunnan province, China. Dominant plant species and soil samples were collected to analysis heavy metal (Cu, Zn, Pb and Cd) accumulation characteristics. The results showed that 100% samples for Zn, Pb, Cd, and 87.5% samples for Cu in the investigated area exceeded the Yunnan geochemical background value of the heavy metals in the soil. There were 36 plants species in communities, among which Epilobium pyrricholophum, Elsholtzia argyi, Artemisia vestita, Tripogon chinensis were the dominant species. Plant species, the number of individuals, Ecological Dominance (Do), Shannon-Wiener index (H'), Simpson diversity index (Dsi) and Pielou evenness index (Epi) were affected by Cd and Cu contents of the soil and sediment. Therefore, the results indicate that Cu and Cd contents and ecological risk in the process of long-term vegetation restoration of small catchment in lead-zinc mine waste area should pay more attention.