Impacts of burrows and mounds formed by plateau rodents on plant species diversity on the Qinghai-Tibetan Plateau

2015 ◽  
Vol 37 (1) ◽  
pp. 117 ◽  
Author(s):  
Ruixin Wu ◽  
Qi Chai ◽  
Jianquan Zhang ◽  
Mengying Zhong ◽  
Yuehua Liu ◽  
...  
Keyword(s):  
Species Diversity ◽  
Tibetan Plateau ◽  
Plant Diversity ◽  
Management Practices ◽  
Source Region ◽  
Diversity Indices ◽  
Rangeland Management ◽  
Community Diversity ◽  
Grassland Productivity ◽  
Total P

The relationships among environmental factors, rodent activity disturbance and plant-community diversity were studied across four sites in a prefecture of the ‘Three-River-Source’ region of the Qinghai-Tibetan Plateau. It was found that burrow number and mound area had little impact on plant diversity indices, which were mainly affected by altitude, soil total P and pH. Altitude and mound area, especially mound area, can strongly affect the aboveground biomass and the vegetation cover of plants was mainly influenced by mound area. There was some evidence that moderate levels of disturbance by rodents could lead to the highest levels of plant diversity. These findings indicated that moderate levels of disturbance by rodents may be beneficial to grassland productivity and plant diversity. Understanding these impacts is vital for better rangeland management practices so that rodents should be controlled within a suitable range rather than being exterminated.

scholarly journals Resource enrichment combined with biomass removal maintains plant diversity and community stability in a long-term grazed grassland

2020 ◽  
Vol 13 (5) ◽  
pp. 611-620
Author(s):  
Feng-Wei Xu ◽  
Jian-Jun Li ◽  
Li-Ji Wu ◽  
Xiao-Ming Lu ◽  
Wen Xing ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Plant Diversity ◽  
Primary Productivity ◽  
Management Practices ◽  
Light Exposure ◽  
Community Stability ◽  
Water Addition ◽  
Biomass Removal

Abstract Aims Long-term heavy grazing reduces plant diversity and ecosystem function by intensifying nitrogen (N) and water limitation. In contrast, the absence of biomass removal can cause species loss by elevating light competition and weakening community stability, which is exacerbated by N and water enrichment. Hence, how to maintain species diversity and community stability is still a huge challenge for sustainable management of worldwide grasslands. Methods We conducted a 4-year manipulated experiment in six long-term grazing blocks to explore combination of resource additions and biomass removal (increased water, N and light availability) on species richness and community stability in semiarid grasslands of Inner Mongolia, China. Important Findings In all blocks treated with the combination of resource additions and biomass removal, primary productivity increased and species richness and community stability were maintained over 4 years of experiment. At both species and plant functional group (PFG) levels, the aboveground biomass of treated plants remained temporally stable in treatments with the combination of N and/or water addition and biomass removal. The maintenance of species richness was primarily caused by the biomass removal, which could increase the amount of light exposure for grasses under resource enrichment. Both species asynchrony and stability of PFGs contributed to the high temporal stability observed in these communities. Our results indicate that management practices of combined resource enrichment with biomass removal, such as grazing or mowing, could not only enhance primary productivity but also maintain plant species diversity, species asynchrony and community stability. Furthermore, as overgrazing-induced degradation and resource enrichment-induced biodiversity loss continue to be major problems worldwide, our findings have important implications for adaptive management in semiarid grasslands and beyond.

Effects of grazing by large herbivores on plant diversity and productivity of semi-arid alpine steppe on the Qinghai-Tibetan Plateau

2015 ◽  
Vol 37 (4) ◽  
pp. 389 ◽  
Author(s):  
Hasbagan Ganjurjav ◽  
Min-jie Duan ◽  
Yun-fan Wan ◽  
Wei-na Zhang ◽  
Qing-zhu Gao ◽  
...  
Keyword(s):  
Species Diversity ◽  
Tibetan Plateau ◽  
Plant Community ◽  
Plant Diversity ◽  
Net Primary Productivity ◽  
Strong Impact ◽  
Aboveground Net Primary Productivity ◽  
Large Herbivores ◽  
Alpine Steppe ◽  
Semi Arid

Grazing by large herbivores may have a strong impact on plant diversity and productivity, but the effects are expected to vary with grazing pressure. The changes in productivity and species diversity of Stipa purpurea-dominated semi-arid alpine steppe grassland were measured under four different stocking rates of Tibetan sheep [no grazing, light (2.4 sheep units ha–1), moderate (3.6 sheep units ha–1), and heavy (6.0 sheep units ha–1) grazing] in a 5-year (2006–2010) grazing experiment on the Qinghai-Tibetan Plateau, China. Herbage mass and aboveground net primary productivity of alpine steppe declined significantly with increasing stocking rate (P < 0.05). Over the 5 years of the experiment, the proportion of forbs and sedges increased significantly under light and moderate grazing; the proportion of grasses decreased significantly, whereas the proportion of S. purpurea did not change compared with the no grazing treatment. Species diversity was highest under moderate grazing and was significantly higher than the no grazing treatment in 2 years (2008 and 2010). Moderate grazing enhanced the species diversity of the plant community due to an increase in the proportion of forbs. There were significant positive linear correlations between herbage mass and species diversity under no and light grazing. Species diversity was not related to productivity under moderate and heavy grazing. In conclusion, grazing by sheep reduced plant productivity; plant diversity increased under low and moderate grazing, and was as a result of changes in the composition of the plant community of a semi-arid alpine steppe.

scholarly journals Phytosociological studies on natural establishment of vegetation in an unreclaimed limestone mining

2003 ◽  
Vol 46 (2) ◽  
pp. 259-269 ◽  
Author(s):  
Rita de Cássia Frenedozo-Soave
Keyword(s):  
Species Diversity ◽  
Plant Diversity ◽  
Environmental Conditions ◽  
Community Organization ◽  
Diversity Indices ◽  
Sao Paulo ◽  
Vegetation Community ◽  
Floristic Similarity ◽  
Number Of Species ◽  
Natural Establishment

Phytosociological structure was studied in limestone mining quarries at Rio Claro, São Paulo, Brazil. Quarries presented a chronosequence, ranging 1 to 40 years old, with focus on vegetation community organization, floristic similarity and plant diversity of three areas in different successive stages, devastated by limestone mining. A total of 1957 individuals distributed in 32 botanical families and 91 species were sampled. Low species diversity was obtained, ranged among quarries ages. In the early-established quarries, Leguminosae, Malvaceae and Sterculiaceae were the families most representative in number of species, while for the age 27, Asteraceae and Poaceae were the most representative. Diversity indices indicated that species diversity changed with the time and was function of environmental conditions.

scholarly journals Effects of fertilization, burning, and grazing on plant community in the long-term fenced grasslands  

2017 ◽  
Vol 63 (No. 4) ◽  
pp. 171-176 ◽  
Author(s):  
Jing Guanghua ◽  
Li Wei ◽  
Yu Kailiang ◽  
Ratajczak Zak ◽  
Kallenbach Robert L ◽  
...  
Keyword(s):  
Species Diversity ◽  
Plant Community ◽  
Aboveground Biomass ◽  
Management Practices ◽  
Functional Group ◽  
Management Practice ◽  
Grassland Productivity ◽  
Group Diversity ◽  
Positive Effect

Fencing is the common management practice to restore degraded grasslands. However, long-term fencing decreases grassland productivity and species diversity. The study was therefore conducted as a three-year (2011–2013) experiment with a randomized complete block in a grassland fenced for 20 years in the Loess Plateau of China, and the effects of fertilization, burning and grazing on aboveground biomass, species and functional group composition, species and some functional group diversity were analysed. Our results showed that the functional group of perennial bunchgrasses dominated the grassland regardless of management practices. However, burning altered species composition (i.e. the unpalatable species, Artemisia sacrorum) more significantly than fertilization or grazing, and surprisingly, nearly quadrupled the functional group of shrubs and semi-shrubs. Fertilization had a positive effect on the aboveground biomass (44.0%), while clearly reducing species diversity (21.9%). Grazing decreased aboveground biomass, but increased species diversity by 15.9%. This study indicated that fertilization influenced plant community through its impact on aboveground biomass, while burning changed plant community by altering dominant species. Thus, it was concluded that fertilizer could further improve community biomass while burning reduced the edibility of grass. Grazing could be carried out to enhance the biodiversity in the long-term fenced grasslands.  

Local perceptions of rangeland degradation and climate change in the pastoral society of Qinghai-Tibetan Plateau

2015 ◽  
Vol 37 (1) ◽  
pp. 11 ◽  
Author(s):  
Xiaoyu Wu ◽  
Xiangfeng Zhang ◽  
Shikui Dong ◽  
Hong Cai ◽  
Tianren Zhao ◽  
...  
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Management Practices ◽  
Gansu Province ◽  
Rangeland Management ◽  
Collective Actions ◽  
Policy Makers ◽  
Economic Changes ◽  
Social Transformations ◽  
Rangeland Degradation

Rangelands provide several valuable ecological services and provide for the livelihoods of local herders on the Qinghai-Tibetan Plateau (QTP). However, rangelands are being degraded due to overgrazing, policy changes and climate change. In this context, a survey was conducted in Zhuaxixiulong township of Gansu Province, China to examine the rangeland management systems and identify problems herders are facing in terms of livestock production and livelihoods using a Participatory Rural Appraisal approach. The results indicated that local herders perceived recent trends in rangeland degradation, climatic change, and political changes, and had developed management practices to adapt to these changes, such as adjusting transhumance patterns, cooperating with local institutions and adopting more collective actions in production practices. This study suggests that, to promote a sustainable rangeland management system in the QTP, policy-makers should recognise indigenous knowledge systems of grazing practices and rangeland management, as well as the need for more advanced technical methods. More attention should be paid to recent changes in climate, social transformations and economic changes to enhance the viability of such a pastoral society. To ensure the sustainability of the social–ecological system, there is a need to strengthen public participation and cooperation with all types of institutions to formulate appropriate policies and improve public services.

scholarly journals Relationship between ecological stoichiometry and community diversity of plant ecosystems in the upper reaches of the Tarim River, China

2018 ◽  
Author(s):  
Jingjing Zhao ◽  
Lu Gong ◽  
Xin Chen
Keyword(s):  
Species Diversity ◽  
Plant Community ◽  
Ecological Stoichiometry ◽  
Diversity Indices ◽  
Community Diversity ◽  
Tarim River ◽  
Arid Zones ◽  
The Tarim River ◽  
P Content ◽  
The Relationship

AbstractAimAlthough it is commonly proposed that nutrient cycling can impact plant community diversity, this relationship has not been fully examined in arid and semi-arid zones. Here, we expand on the framework for evaluating the relationship between biodiversity and ecological stoichiometry by scaling up from the level of the community.LocationThe upper reaches of the Tarim River (Northwest China, 80°10’-84°36’E, 0°25’-41°10’N).MethodsWe used multivariate analysis of variance to compare the stoichiometric characteristics and species diversity indices of sampled plant communities. We also measured carbon (C), nitrogen (N), and phosphorous (P) content of plants. We then assessed correlations between community stoichiometry and species diversity through structural equation models (SEM) and redundancy analysis (RDA).ResultsWe found that the differences between stoichiometric characteristics and community diversity indices were highly significant. The Margalef index was strongly related to C and P content. The Simpson’s index and Shannon-Weaner index were most strongly correlated with C content. Pielou’s index was closely related to C and N contents, and the C:N and C:P ratios were important at driving ecological dominance.Main ConclusionsOur study highlights the importance of ecological stoichiometry in driving community assembly and diversity within a desert ecosystems in northwestern China. The relationship between eclogical stoichiometry in the desert plant community had an effect on species diversity, and it was a good indicator of plant community diversity.

A comparison of biodiversity–ecosystem function relationships in alpine grasslands across a degradation gradient on the Qinghai–Tibetan Plateau

2015 ◽  
Vol 37 (1) ◽  
pp. 45 ◽  
Author(s):  
Xuexia Wang ◽  
Shikui Dong ◽  
Ruth Sherman ◽  
Quanru Liu ◽  
Shiliang Liu ◽  
...  
Keyword(s):  
Species Diversity ◽  
Tibetan Plateau ◽  
Plant Diversity ◽  
Ecosystem Function ◽  
Aboveground Biomass ◽  
Soil Loss ◽  
Plant Biomass ◽  
Plant Functional Groups ◽  
Alpine Grasslands ◽  
C And N

To examine biodiversity–ecosystem function relationships in alpine grasslands of the Qinghai–Tibetan Plateau, we compared differences in plant species and functional group diversity (sedges, grasses, legumes and non-leguminous forbs) to aboveground biomass, soil carbon (C) and nitrogen (N) pools and soil loss in five sites that ranged from healthy to severely degraded grasslands. Plant diversity decreased from 36 species in the healthy grassland to 15 species in the severely degraded grassland, and the plant functional groups changed from predominantly grasses and sedges to mostly forbs as the level of degradation increased. Plant biomass and soil pools of C and N decreased whereas soil loss and the amount of bare ground increased across the degradation gradient from healthy to severely degraded grasslands. Simple linear regressions showed strong positive relationships between species diversity and aboveground biomass of sedges, grasses and legumes and between soil C and N pools, but negative relationships between species diversity and non-leguminous forbs and soil loss. Our results provide strong evidence that plant diversity in grasslands on the Qinghai–Tibetan Plateau is positively related to primary productivity, C and N storage in soils and soil conservation, and that grassland degradation is impairing ecosystem function resulting in a loss in ecosystem services.

scholarly journals Decades of Recovery From Sheep Grazing Reveal No Effects on Plant Diversity Patterns Within Icelandic Tundra Landscapes

2021 ◽  
Vol 8 ◽  
Author(s):  
Martin A. Mörsdorf ◽  
Virve T. Ravolainen ◽  
Nigel G. Yoccoz ◽  
Thóra Ellen Thórhallsdóttir ◽  
Ingibjörg Svala Jónsdóttir
Keyword(s):  
Species Richness ◽  
Plant Growth ◽  
Plant Communities ◽  
Plant Diversity ◽  
Management Practices ◽  
Spatial Scales ◽  
Plant Productivity ◽  
Community Diversity ◽  
Growth Forms ◽  
Diversity Patterns

Tundra plant communities are often shaped by topography. Contrasting wind exposure, slopes of different inclination and landforms of different curvature affect habitat conditions and shape plant diversity patterns. The majority of tundra is also grazed by ungulates, which may alter topographically induced plant diversity patterns, but such effects may depend on the spatial scales of assessments. Here we ask whether topographically induced patterns of within (alpha) and between (beta) plant community diversity are different in contrasting grazing regimes. We studied plant communities within tundra landscapes that were located in the North and Northwest of Iceland. Half of the studied landscapes were grazed by sheep, whereas the other half was currently un-grazed and recovering for several decades (up to 60 years). Alpha and beta diversity were assessed on explicitly defined, nested spatial scales, which were determined by topographical units. Although we contrasted currently grazed vegetation to vegetation that witnessed several decades of grazing recovery, we found no statistically significant differences in plant diversity patterns. We relate these findings to the low resilience of our study system toward grazing disturbances, which has important implications for management practices in the tundra. Effects of topography on species richness were only found for specific spatial scales of analyses. Species rich topographical units were associated with relatively large biomass of plant growth forms that promote nutrient availability and potential plant productivity in the tundra, such as forbs. This suggests that biomass of such plant growth forms within habitats can be a useful proxy of potential plant productivity and may predict spatial patterns of plant species richness in tundra.

scholarly journals Comparison of four species diversity indices in mangrove community

2021 ◽  
Vol 22 (9) ◽  
Author(s):  
Hanjar Mulya ◽  
Yanto Santosa ◽  
Iwan Hilwan
Keyword(s):  
Species Diversity ◽  
Pearson Correlation ◽  
Diversity Indices ◽  
Community Diversity ◽  
Statistical Characteristics ◽  
Margalef Index ◽  
Diversity Assessment ◽  
Species Diversity Indices ◽  
Suitable Index ◽  
Mangrove Communities

Abstract. Mulya H, Santosa Y, Hilwan I. 2021. Comparison of four species diversity indices in mangrove community. Biodiversitas 22: 3648-3655. Mangrove communities have a tidal environment that affects their species composition, which may be finite but the abundance may vary between species individuals. Many ecologists have used indices to measure species diversity without knowing the best suitable index for the community and its statistical characteristics. Therefore, this study aimed to compare species diversity indices in mangrove communities to obtain the best and most appropriate index for mangrove diversity. The comparison was done using the Simpson (1-D), Shannon, Menhinick, and Margalef indices, which were widely used and considered the best measures in various communities. The data was obtained from the field sampling using a single plot of 80×40 m2, and then it was simulated to obtain standardized variables so that the indices got the same treatment. It was calculated with descriptive statistics and species diversity indices among other Simpson, Margalef, Shannon, and Menhinick indices. Pearson correlation and UPGMA cluster were used to get conformity based on the best index criteria. The results showed the Margalef index was the best in performance that passed the assessment criteria more than Simpson (1-D), Shannon, and Menhinick index. It had a low correlation with sample variance and normality marker but had high variability of the index value. It was also sensitive to the number of species, good reduced individual sample, and good correlation with similar indices. Thus, we concluded that the Margalef index was the best index for mangrove community diversity measurement. The index was recommended for monitoring and evaluating the species diversity assessment for the mangrove community. It should not use several species diversity indices with similar meaning.

scholarly journals Legumes increase grassland productivity with no effect on nitrous oxide emissions

2019 ◽  
Vol 446 (1-2) ◽  
pp. 163-177 ◽  
Author(s):  
Arlete S. Barneze ◽  
Jeanette Whitaker ◽  
Niall P. McNamara ◽  
Nicholas J. Ostle
Keyword(s):  
Management Practices ◽  
Production Systems ◽  
N Uptake ◽  
Relative Proportion ◽  
Management Strategies ◽  
Ghg Emissions ◽  
Chemical Properties ◽  
Nitrous Oxide Emissions ◽  
Mineral N ◽  
Grassland Productivity

Abstract Aims Grasslands are important agricultural production systems, where ecosystem functioning is affected by land management practices. Grass-legume mixtures are commonly cultivated to increase grassland productivity while reducing the need for nitrogen (N) fertiliser. However, little is known about the effect of this increase in productivity on greenhouse gas (GHG) emissions in grass-legume mixtures. The aim of this study was to investigate interactions between the proportion of legumes in grass-legume mixtures and N-fertiliser addition on productivity and GHG emissions. We tested the hypotheses that an increase in the relative proportion of legumes would increase plant productivity and decrease GHG emissions, and the magnitude of these effects would be reduced by N-fertiliser addition. Methods This was tested in a controlled environment mesocosm experiment with one grass and one legume species grown in mixtures in different proportions, with or without N-fertiliser. The effects on N cycling processes were assessed by measurement of above- and below-ground biomass, shoot N uptake, soil physico-chemical properties and GHG emissions. Results Above-ground productivity and shoot N uptake were greater in legume-grass mixtures compared to grass or legume monocultures, in fertilised and unfertilised soils. However, we found no effect of legume proportion on N2O emissions, total soil N or mineral-N in fertilised or unfertilised soils. Conclusions This study shows that the inclusion of legumes in grass-legume mixtures positively affected productivity, however N cycle were in the short-term unaffected and mainly affected by nitrogen fertilisation. Legumes can be used in grassland management strategies to mitigate climate change by reducing crop demand for N-fertilisers.

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