scholarly journals The Diversity and Community Assembly Process of Wetland Plants from Lakeshores on the Qinghai-Tibetan Plateau

Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 685
Author(s):  
Shasha Cui ◽  
Jian Ouyang ◽  
Yu Lu ◽  
Wenzhi Liu ◽  
Wenyang Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Plant Communities ◽  
Wetland Plants ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Weak Selection ◽  
Wetland Plant Communities ◽  
Α Diversity ◽  
Edaphic Properties ◽  
Ecological Drift

Unravelling the patterns, potential processes and mechanisms underlying biodiversity has always been a crucial issue in community ecology. It is also a necessary first step for any conservation and restoration to better adapt fragile ecosystems to a changing climate. However, little is known regarding the structure and maintenance of plant communities in typical high-altitude wetlands. Here, we made a comprehensive analysis of the diversity and composition of wetland plant communities based on the distribution of plants near the shorelines of 19 lakes across the Qinghai-Tibetan Plateau. The latitude, mean annual temperature (MAT) and mean annual precipitation (MAP), along with the edaphic properties, were the dominant predictors affecting the taxonomic and phylogenetic α-diversity. Besides diversification, ecological drift, mixing with weak dispersal and weak selection shaped the community composition of wetland plants in our study. The latitude and MAP predictors, although modest, showed an impact on the community structure.

scholarly journals Temperature and Precipitation Drive Elevational Patterns of Microbial Beta Diversity in Alpine Grasslands

2021 ◽  
Author(s):  
Xiaoqin Yang ◽  
Yue Li ◽  
Bin Niu ◽  
Qiuyu Chen ◽  
Yilun Hu ◽  
...  
Keyword(s):  
Species Richness ◽  
Tibetan Plateau ◽  
Community Composition ◽  
Beta Diversity ◽  
Microbial Community Composition ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
The Tibetan Plateau ◽  
Alpine Grasslands ◽  
Temperature And Precipitation

Abstract Understanding the mechanisms underlying biodiversity patterns is a central issue in ecology, while how temperature and precipitation jointly control the elevational patterns of microbes is understudied. Here, we studied the effects of temperature, precipitation and their interactions on the alpha and beta diversity of soil archaea and bacteria in alpine grasslands along an elevational gradient of 4,300-5,200 m on the Tibetan Plateau. Alpha diversity was examined on the basis of species richness and evenness, and beta diversity was quantified with the recently developed metric of local contributions to beta diversity (LCBD). Typical alpine steppe and meadow ecosystems were distributed below and above 4,850 m, respectively, which was consistent with the two main constraints of mean annual temperature (MAT) and mean annual precipitation (MAP). Species richness and evenness showed decreasing elevational patterns in archaea and nonsignificant or U-shaped patterns in bacteria. The LCBD of both groups exhibited significant U-shaped elevational patterns, with the lowest values occurring at 4,800 m. For the three diversity metrics, soil pH was the primary explanatory variable in archaea, explaining over 20.1% of the observed variation, whereas vegetation richness, total nitrogen and the K/Al ratio presented the strongest effects on bacteria, with relative importance values of 16.1%, 12.5% and 11.6%, respectively. For the microbial community composition of both archaea and bacteria, the moisture index showed the dominant effect, explaining 17.6% of the observed variation, followed by MAT and MAP. Taken together, temperature and precipitation exerted considerable indirect effects on microbial richness and evenness through local environmental and energy supply-related variables, such as vegetation richness, whereas temperature exerted a larger direct influence on LCBD and the community composition. Our findings highlighted the profound influence of temperature and precipitation interactions on microbial beta diversity in alpine grasslands on the Tibetan Plateau.

scholarly journals Biological and extrinsic correlates of extinction risk in Chinese lizards

2021 ◽  
Author(s):  
Yuxi Zhong ◽  
Chuanwu Chen ◽  
Yanping Wang
Keyword(s):  
Body Size ◽  
Extinction Risk ◽  
Species Traits ◽  
Geographic Range ◽  
Range Size ◽  
Habitat Specialization ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Small Range ◽  
Extrinsic Factors

Abstract China is a country with one of the most species rich reptile faunas in the world. However, nearly a quarter of Chinese lizard species assessed by the China Biodiversity Red List are threatened. Nevertheless, to date, no study has explicitly examined the pattern and processes of extinction and threat in Chinese lizards. In this study, we conducted the first comparative phylogenetic analysis of extinction risk in Chinese lizards. We addressed the following three questions: 1) What is the pattern of extinction and threat in Chinese lizards? 2) Which species traits and extrinsic factors are related to their extinction risk? 3) How can we protect Chinese lizards based on our results? We collected data on ten species traits (body size, clutch size, geographic range size, activity time, reproductive mode, habitat specialization, habitat use, leg development, maximum elevation, and elevation range) and seven extrinsic factors (mean annual precipitation, mean annual temperature, mean annual solar insolation, normalized difference vegetation index (NDVI), human footprint, human population density, and human exploitation). After phylogenetic correction, these variables were used separately and in combination to assess their associations with extinction risk. We found that Chinese lizards with small geographic range, large body size, high habitat specialization, and living in high precipitation areas were vulnerable to extinction. Conservation priority should thus be given to species with the above extinction-prone traits so as to effectively protect Chinese lizards. Preventing future habitat destruction should also be a primary focus of management efforts because species with small range size and high habitat specialization are particularly vulnerable to habitat loss.

Spatial Patterns and Drivers of Soil Chemical Properties in a Typical Hickory Plantation

2021 ◽  
Author(s):  
Mengjiao Sun ◽  
Enqing Hou ◽  
Jiasen Wu ◽  
Jianqin Huang ◽  
Xingzhao Huang
Keyword(s):  
Random Forest ◽  
Soil Nutrients ◽  
Spatial Patterns ◽  
Abiotic Factors ◽  
Soil Nutrient ◽  
Parent Material ◽  
Mean Annual Precipitation ◽  
Nutrient Concentrations ◽  
Available Phosphorus ◽  
Mean Annual Temperature

Abstract Background: Soil nutrients play critical roles in regulating and improving the sustainable development of economic forests. Consequently, an elucidation of the spatial patterns and drivers of soil nutrients in these forests is fundamental to their management. For this study, we collected 314 composite soils at a 0-30 cm depth from a typical hickory plantation in Lin 'an, Zhejiang Province, China. We determined the concentrations of macronutrients (i.e., soil organic carbon, hydrolyzed nitrogen, available phosphorus, and available potassium) and micronutrients (i.e., iron, manganese, zinc, and copper.) of the soils. We employed random forest analysis to quantify the relative importance of soil-forming factors to predict the soil nutrient concentrations, which could then be extrapolated to the entire hickory region. Results: Random forest models explained 61%–88% of the variations in soil nutrient concentrations. The mean annual temperature and mean annual precipitation were the most important predictor of soil macronutrient and micronutrient concentrations. Moreover, parent material was another key predictor of soil available phosphorus and micronutrient concentrations. Mapping results demonstrated the importance of climate in controlling the spatial distribution of soil nutrient concentrations at finer scales, as well as the effect of parent material, topography, stand structure, and management measures of hickory plantations. Conclusions: Our study highlights the biotic factors, abiotic factors, and management factors control over soil macronutrient and micronutrient concentrations, which have significant implications for the sustainability of soil nutrients in forest plantations.

scholarly journals Upside-down fluxes Down Under: CO<sub>2</sub> net sink in winter and net source in summer in a temperate evergreen broadleaf forest

2018 ◽  
Vol 15 (12) ◽  
pp. 3703-3716 ◽  
Author(s):  
Alexandre A. Renchon ◽  
Anne Griebel ◽  
Daniel Metzen ◽  
Christopher A. Williams ◽  
Belinda Medlyn ◽  
...  
Keyword(s):  
Large Scale ◽  
Vegetation Index ◽  
Ecosystem Respiration ◽  
Vapour Pressure Deficit ◽  
Summer Rainfall ◽  
Mean Annual Precipitation ◽  
Surface Conductance ◽  
Mean Annual Temperature ◽  
Eddy Covariance Method ◽  
Area Index

Abstract. Predicting the seasonal dynamics of ecosystem carbon fluxes is challenging in broadleaved evergreen forests because of their moderate climates and subtle changes in canopy phenology. We assessed the climatic and biotic drivers of the seasonality of net ecosystem–atmosphere CO2 exchange (NEE) of a eucalyptus-dominated forest near Sydney, Australia, using the eddy covariance method. The climate is characterised by a mean annual precipitation of 800 mm and a mean annual temperature of 18 ∘C, hot summers and mild winters, with highly variable precipitation. In the 4-year study, the ecosystem was a sink each year (−225 g C m−2 yr−1 on average, with a standard deviation of 108 g C m−2 yr−1); inter-annual variations were not related to meteorological conditions. Daily net C uptake was always detected during the cooler, drier winter months (June through August), while net C loss occurred during the warmer, wetter summer months (December through February). Gross primary productivity (GPP) seasonality was low, despite longer days with higher light intensity in summer, because vapour pressure deficit (D) and air temperature (Ta) restricted surface conductance during summer while winter temperatures were still high enough to support photosynthesis. Maximum GPP during ideal environmental conditions was significantly correlated with remotely sensed enhanced vegetation index (EVI; r2 = 0.46) and with canopy leaf area index (LAI; r2 = 0.29), which increased rapidly after mid-summer rainfall events. Ecosystem respiration (ER) was highest during summer in wet soils and lowest during winter months. ER had larger seasonal amplitude compared to GPP, and therefore drove the seasonal variation of NEE. Because summer carbon uptake may become increasingly limited by atmospheric demand and high temperature, and because ecosystem respiration could be enhanced by rising temperatures, our results suggest the potential for large-scale seasonal shifts in NEE in sclerophyll vegetation under climate change.

scholarly journals High Resolution of Water Availability for Emilia-Romagna Region over 1961–2015

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
F. Cervi ◽  
M. M. Nistor
Keyword(s):  
Water Availability ◽  
Soil Surface ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
North East ◽  
The North ◽  
Precipitation Decrease ◽  
Normal Period ◽  
Emilia Romagna Region ◽  
Annual Water

In this study, monthly time series of precipitations and temperatures from 1024 controlled and homogeneous meteorological stations located in the Emilia-Romagna region (northern Italy) are processed in order to assess potential climate changes that occurred during the period 1961–2015. Normal period as baseline between 1961 and 1990 (1990s) and recent period between 1991 and 2015 (2010s) were adopted in this study to analyse the possible effect of climate change on water availability during long-term period. Based on monthly and annual temperature (TT), precipitation (PP), and potential (ET0), the actual evapotranspiration (AET0) and water availability (WA) were computed at high spatial resolution. Between the two analysed periods, during the 2010s, it was found an increase in the maximum mean annual temperature by 1.08°C while the maximum mean annual precipitation saw a slight decrease (from 2222 mm to 2086 mm). The precipitation decrease is more intense in the South and West sectors of area (8%) and mainly depends on negative changes taking place during the winter and the beginning of spring (from December to March). The maximum mean annual ET0 and AET0 reached values of 663 mm and 565 mm during the 1990s, while during the 2010s, the found values were 668 mm and 572 mm, respectively. Because of the decrease in precipitation and increase in the ET0 and AET0, the WA (the proportion of precipitation that is available at the soil surface for subsequent infiltration and runoff processes) shows a reduction (about 10–20%) in the whole region, with exception of the North-East part of the Emilia-Romagna region. The decrease in the mean annual water availability induces severe issues concerning the water resources management across the whole Emilia-Romagna region.

scholarly journals Plant diversity in sedimentary DNA obtained from high-latitude (Siberia) and high-elevation lakes (China)

2020 ◽  
Vol 8 ◽  
Author(s):  
Kathleen Stoof-Leichsenring ◽  
Sisi Liu ◽  
Weihan Jia ◽  
Kai Li ◽  
Luidmila Pestryakova ◽  
...  
Keyword(s):  
Lake Sediments ◽  
Plant Diversity ◽  
Environmental Conditions ◽  
Environmental Changes ◽  
The Arctic ◽  
Mean Annual Precipitation ◽  
Reference Database ◽  
Mean Annual Temperature ◽  
Diversity Assessment ◽  
Recent Climate

Plant diversity in the Arctic and at high altitudes strongly depends on and rebounds to climatic and environmental variability and is nowadays tremendously impacted by recent climate warming. Therefore, past changes in plant diversity in the high Arctic and high-altitude regions are used to infer climatic and environmental changes through time and allow future predictions. Sedimentary DNA (sedDNA) is an established proxy for the detection of local plant diversity in lake sediments, but still relationships between environmental conditions and preservation of the plant sedDNA proxy are far from being fully understood. Studying modern relationships between environmental conditions and plant sedDNA will improve our understanding under which conditions sedDNA is well-preserved helping to a.) evaluate suitable localities for sedDNA approaches, b.) provide analogues for preservation conditions and c.) conduct reconstruction of plant diversity and climate change. This study investigates modern plant diversity applying a plant-specific metabarcoding approach on sedimentary DNA of surface sediment samples from 262 lake localities covering a large geographical, climatic and ecological gradient. Latitude ranges between 25°N and 73°N and longitude between 81°E and 161°E, including lowland lakes and elevated lakes up to 5168 m a.s.l. Further, our sampling localities cover a climatic gradient ranging in mean annual temperature between -15°C and +18°C and in mean annual precipitation between 36­ and 935 mm. The localities in Siberia span over a large vegetational gradient including tundra, open woodland and boreal forest. Lake localities in China include alpine meadow, shrub, forest and steppe and also cultivated areas. The assessment of plant diversity in the underlying dataset was conducted by a specific plant metabarcoding approach. We provide a large dataset of genetic plant diversity retrieved from surface sedimentary DNA from lakes in Siberia and China spanning over a large environmental gradient. Our dataset encompasses sedDNA sequence data of 259 surface lake sediments and three soil samples originating from Siberian and Chinese lakes. We used the established chloroplastidal P6 loop trnL marker for plant diversity assessment. The merged, filtered and assigned dataset includes 15,692,944 read counts resulting in 623 unique plant DNA sequence types which have a 100% match to either the EMBL or to the specific Arctic plant reference database. The underlying dataset includes a taxonomic list of identified plants and results from PCR replicates, as well as extraction blanks (BLANKs) and PCR negative controls (NTCs), which were run along with the investigated lake samples. This collection of plant metabarcoding data from modern lake sediments is still ongoing and additional data will be released in the future.

scholarly journals Genome size mediates the effect of environmental filtering in determining plant β-diversity across temperate grasslands

2021 ◽  
Author(s):  
Hai-Yang Zhang ◽  
Xiaotao Lü ◽  
cunzheng wei ◽  
Jeff Powell ◽  
Xiaobo Wang ◽  
...  
Keyword(s):  
Genome Size ◽  
Community Assembly ◽  
Nuclear Dna ◽  
Environmental Filtering ◽  
Nuclear Dna Content ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Nitrogen And Phosphorus ◽  
Temperate Grasslands ◽  
Β Diversity

Elucidating mechanisms underlying community assembly and biodiversity patterns is central to ecology and evolution. Genome size (GS, i.e. nuclear DNA content) determines species’ capacity to tolerate environmental stress or to exploit new environments and therefore potentially drive community assembly. However, its role in driving β-diversity (i.e., the site-to-site variability in species composition) remains unclear. We measured GS for 169 plant species and investigated their occurrences within plant communities across 52 sites spanning a 3200-km transect in the temperate grasslands of China. We found environmental factors showed larger effects on β-diversity of large-GS than that of small-GS species. Community weighted mean GS increased with mean annual precipitation, soil total nitrogen and phosphorus concentrations, but decreased with mean annual temperature, suggesting a negative selection against species with large GS in resources-limited or warmer climates. These findings highlight the roles for GS in driving community assembly and predicting species responses to climate change.

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