scholarly journals Environmental filtering of body size and darker coloration in pollinator communities indicate thermal restrictions on bees, but not flies, at high elevations

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7867 ◽  
Author(s):  
Lindsie M. McCabe ◽  
Neil S. Cobb ◽  
Bradley J. Butterfield
Keyword(s):  
Body Size ◽  
Elevation Gradient ◽  
Species Abundance ◽  
Environmental Filtering ◽  
Mean Annual Temperature ◽  
Body Volume ◽  
Weighted Mean ◽  
Elevation Gradients ◽  
Community Weighted Mean ◽  
High Elevations

Background Bees and flies are the two most dominant pollinator taxa in mountain environments of the Southwest USA. Communities of both taxa change dramatically along elevation gradients. We examined whether bee and fly traits would also change along elevation gradients and if so, do they change in a predictable way related to a decrease in temperature as elevation increases. Methods We used insect body size and darkness traits as proxies for energetic requirements and indicators of cold tolerance in order to assess patterns of bee and fly community trait differences along an elevation gradient. We examined 1,922 individuals of bees and flies sampled along an elevation gradient ranging from 2,400 meters to 3,200 meters and from 9.6 °C to 5.2 °C mean annual temperature. We examined bees and flies separately using community weighted means (site-level trait values weighted by species abundance) and estimates of environmental filtering (quantified as the inverse of the standardized range of trait values). Results Bees and flies exhibited two somewhat distinct patterns; (1) Community weighted mean body volume and darkness of bees increased sharply at the highest elevation, and the intensity of environmental filtering also increased with elevation. This was due to both a change among bee populations within a species as well as species replacement at the highest elevation. (2) Community weighted mean body volume and darkness of flies also increased moderately with increasing elevation, but did not exhibit patterns of significant environmental filtering. In fact, the intensity of environmental filtering as indicated by the range of fly body volume weakened with elevation. Conclusion The increase in filter intensity at high elevations exhibited by bees suggests a significant limitation on the breadth of viable functional strategies for coping with extreme cold, at least within this regional species pool. Flies, on the other hand, do not appear to be limited by high elevations, indicating that the shift from bee to fly dominance at high elevations may be due, at least in part, to greater environmental constraints on bee adaptation to colder environments.

scholarly journals Indication of a reduction in the cover of thin-leaved plants in Danish grasslands over an eight-year period

2019 ◽  
Author(s):  
Christian Damgaard
Keyword(s):  
Plant Traits ◽  
Species Abundance ◽  
Leaf Traits ◽  
Statistical Modelling ◽  
Weighted Mean ◽  
Habitat Types ◽  
Plant Trait ◽  
Dependent Variables ◽  
Continuous Plant ◽  
Community Weighted Mean

AbstractAcross four grassland habitat types, the cover of thin-leaved plants was found to decrease significantly, but generally only limited trait selection was observed on leaf traits (SLA and LDMC) in a study of an extensive Danish grassland vegetation dataset from an eight-year period. The mostly negative result of this study may partly be due to the relatively conservative analysis, where the continuous plant trait variables are used for grouping plant species into functional types, which are then treated as dependent variables. This procedure is in contrast to most other analyses of trait selection, where it is the community weighted mean of the traits that is used as the dependent variable. However, it is not the traits, but rather individual plants that are sampled and, consequently, it is important to consider the sampling of species abundance in the statistical modelling of plant traits. This misapprehension has not received sufficient proper attention in the plant trait literature.

Community assembly processes along a sub-Mediterranean elevation gradient: analyzing the interdependence of trait community weighted mean and functional diversity

Plant Ecology ◽  
2019 ◽  
Vol 220 (12) ◽  
pp. 1139-1151 ◽  
Author(s):  
Alessandro Bricca ◽  
Luisa Conti ◽  
Maria Federico Tardella ◽  
Andrea Catorci ◽  
Marco Iocchi ◽  
...  
Keyword(s):  
Functional Diversity ◽  
Community Assembly ◽  
Elevation Gradient ◽  
Weighted Mean ◽  
Community Weighted Mean

Variation of body size, age structure and growth of a temperate frog, Rana chensinensis, over an elevational gradient in Northern China

2009 ◽  
Vol 30 (1) ◽  
pp. 111-117 ◽  
Author(s):  
Xin Lu ◽  
Lina Tong ◽  
Xiaoyan Ma
Keyword(s):  
Life History ◽  
Body Size ◽  
Northern China ◽  
Elevational Gradient ◽  
Age And Growth ◽  
Mean Annual Temperature ◽  
Adult Males ◽  
Elevation Gradients ◽  
Rana Chensinensis ◽  
Growing Seasons

AbstractIdentifying the patterns of body size, age and growth in relation to environments may help us to understand the evolution of life history of organisms. This study compared the variability in these demographic traits of a temperate frog, Rana chensinensis, among populations from Northern China located at three elevations (567, 1470 and 1700 m) with distinct mean annual temperature (12.1, 5.8 and 3.9°C). Overall, frogs from higher elevations tended to be larger in body size, partially because despite shorter growing seasons, they lived longer as a result of delayed maturity. However, discordance with the expected cline was detected between neighboring populations and the variation was sex specific. Adult females became significantly older and larger as elevation varied from 567 m to 1470 m, but the two traits no longer increased with an elevational shift from 1470 m to 1700 m. Adult males at 1470 m were similar in age and size to animals at 567 m but significantly younger and smaller than those at 1700 m. This suggested that sexes could be exposed to different pressures along elevation gradients with females being stronger than males in life history responses to the elevation-induced environmental change. We also showed that factors other than age also contributed to size differences both among populations and between the sexes.

scholarly journals Empirical Evaluation of the Elevational Rapoport’s Rule: The Species Richness Patterns for Vascular Plants on Seorak Mountain, Korea

2021 ◽  
Author(s):  
Ji-Dong Kim ◽  
Mi-Hyun Lee ◽  
Juhyeon Song ◽  
Seong Yeob Byeon ◽  
Jeong Eun Lee ◽  
...  
Keyword(s):  
Plant Species ◽  
Life Form ◽  
Elevation Gradient ◽  
Empirical Evaluation ◽  
Northeast Asia ◽  
Species Abundance ◽  
Life Forms ◽  
Elevation Gradients ◽  
Mountainous Regions ◽  
Abundance Patterns

Research on species abundance patterns and the advanced elevational Rapoport rule (ERR) has been widespread in recent years; however, for the temperate mountainous regions in northeast Asia, such research is lacking. Here, we collected plant species from the Seorak Mountain in northeast Asia through field surveys. The species were divided into 11 groups according to the life-form types and phytogeography affinities of each species. The ERR was tested using Steven’s method and by examining the species abundance patterns of each group. The species abundance patterns revealed a positive multimodal pattern along the elevation gradient, but phytogeography affinities (increasing trend) and life-form (unimodal) exhibited different patterns. The elevation gradients (1350 m for the mean elevation-range relationships), which are affected by the boundary effect and different life-forms, did not consistently support the ERR. However, herbs as well as rare, endemic, and red list species showed consistent support for the ERR, which can be influenced by phytogeography affinities. Thus, the results from Seorak Mountain showed that the ERR was not consistent for different plant life-forms in the same area. The result of our field survey revealed that life-forms in the plant species did not support ERR, whereas phytogeography affinities could support and explain ERR.

FLEXIBLE SOIL MICROBIAL CARBON METABOLISM ACROSS AN ASIAN ELEVATION GRADIENT

Radiocarbon ◽  
2021 ◽  
pp. 1-17
Author(s):  
Yishan Jiang ◽  
Dayi Zhang ◽  
Nicholas J Ostle ◽  
Chunling Luo ◽  
Yan Wang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Carbon ◽  
Elevation Gradient ◽  
Mean Annual Temperature ◽  
The Tibetan Plateau ◽  
Microbial Composition ◽  
Elevation Gradients ◽  
Soil Microbial ◽  
Microbial C ◽  
C Metabolism

ABSTRACT The function and change of global soil carbon (C) reserves in natural ecosystems are key regulators of future carbon-climate coupling. Microbes play a critical role in soil carbon cycling and yet there is poor understanding of their roles and C metabolism flexibility in many ecosystems. We wanted to determine whether vegetation type and climate zone influence soil microbial community composition (fungi and bacteria) and carbon resource preference. We used a biomarker (phospholipid fatty acids, PLFAs), natural abundance 13C and 14C probing approach to measure soil microbial composition and C resource use, along a 1900–4167-m elevation gradient on Mount Gongga (7556 m asl), China. Mount Gongga has a vertical mean annual temperature gradient of 1.2–10.1°C and a diversity of typical vegetation zones in the Tibetan Plateau. Soils were sampled at 10 locations along the gradient capturing distinct vegetation types and climate zones from lowland subtropical-forest to alpine-meadow. PLFA results showed that microbial communities were composed of 2.1–51.7% bacteria and 2.0–23.2% fungi across the elevation gradient. Microbial biomass was higher and the ratio of soil fungi to bacteria (F/B) was lower in forest soils compared to meadow soils. δ13C varied between −33‰ to −17‰ with C3 plant carbon sources dominant across the gradient. Soil organic carbon (SOC) turnover did not vary among three soils we measured from three forest types (i.e., evergreen broadleaved subtropical, mixed temperate, coniferous alpine) and dissolved organic carbon (DOC) turnover decreased with soil elevation. Forest soil microbial PLFA 14C and δ13C measurements showed that forest type and climate were related to different microbial C use. The 14C values of microbial PLFAs i15, a15, 16:1, br17 decreased with elevation while those of C16:0, cyC17, and cyC19 did not show much difference among three forest ecosystems. Bacteria and bacillus represented by C16:1 and brC17 showed considerable microbial C metabolism flexibility and tended to use ancient carbon at higher altitudes. Anaerobes represented by cyC17 and cyC19 showed stronger C metabolism selectivity. Our findings reveal specific C source differences between and within soil microbial groups along elevation gradients.

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.

scholarly journals Multi-Year NDVI Values as Indicator of the Relationship between Spatiotemporal Vegetation Dynamics and Environmental Factors in the Qaidam Basin, China

2021 ◽  
Vol 13 (7) ◽  
pp. 1240
Author(s):  
Junpeng Lou ◽  
Guoyin Xu ◽  
Zhongjing Wang ◽  
Zhigang Yang ◽  
Sanchuan Ni
Keyword(s):  
Environmental Factors ◽  
Vegetation Dynamics ◽  
Vegetation Index ◽  
Qaidam Basin ◽  
Elevation Gradient ◽  
Practical Significance ◽  
Elevation Gradients ◽  
Relative Contribution ◽  
Significant Difference ◽  
Different Altitudes

The Qaidam Basin is a unique and complex ecosystem, wherein elevation gradients lead to high spatial heterogeneity in vegetation dynamics and responses to environmental factors. Based on the remote sensing data of Moderate Resolution Imaging Spectroradiometer (MODIS), Tropical Rainfall Measuring Mission (TRMM) and Global Land Data Assimilation System (GLDAS), we analyzed the spatiotemporal variations of vegetation dynamics and responses to precipitation, accumulative temperature (AT) and soil moisture (SM) in the Qaidam Basin from 2001 to 2016. Moreover, the contribution of those factors to vegetation dynamics at different altitudes was analyzed via an artificial neural network (ANN) model. The results indicated that the Normalized Difference Vegetation Index (NDVI) values in the growing season showed an overall upward trend, with an increased rate of 0.001/year. The values of NDVI in low-altitude areas were higher than that in high-altitude areas, and the peak values of NDVI appeared along the elevation gradient at 4400–4600 m. Thanks to the use of ANN, we were able to detect the relative contribution of various environmental factors; the relative contribution rate of AT to the NDVI dynamic was the most significant (35.17%) in the low-elevation region (< 2900 m). In the mid-elevation area (2900–3900 m), precipitation contributed 44.76% of the NDVI dynamics. When the altitude was higher than 3900 m, the relative contribution rates of AT (39.50%) and SM (38.53%) had no significant difference but were significantly higher than that of precipitation (21.97%). The results highlight that the different environmental factors have various contributions to vegetation dynamics at different altitudes, which has important theoretical and practical significance for regulating ecological processes.

scholarly journals New glacier evidence for ice-free summits during the life of the Tyrolean Iceman

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pascal Bohleber ◽  
Margit Schwikowski ◽  
Martin Stocker-Waldhuber ◽  
Ling Fang ◽  
Andrea Fischer
Keyword(s):  
Elevation Gradient ◽  
Ice Age ◽  
Detailed Knowledge ◽  
New Approach ◽  
Radiocarbon Age ◽  
Alpine Glaciers ◽  
The Alps ◽  
Tyrolean Iceman ◽  
High Elevations ◽  
Age Constraints

AbstractDetailed knowledge of Holocene climate and glaciers dynamics is essential for sustainable development in warming mountain regions. Yet information about Holocene glacier coverage in the Alps before the Little Ice Age stems mostly from studying advances of glacier tongues at lower elevations. Here we present a new approach to reconstructing past glacier low stands and ice-free conditions by assessing and dating the oldest ice preserved at high elevations. A previously unexplored ice dome at Weißseespitze summit (3500 m), near where the “Tyrolean Iceman” was found, offers almost ideal conditions for preserving the original ice formed at the site. The glaciological settings and state-of-the-art micro-radiocarbon age constraints indicate that the summit has been glaciated for about 5900 years. In combination with known maximum ages of other high Alpine glaciers, we present evidence for an elevation gradient of neoglaciation onset. It reveals that in the Alps only the highest elevation sites remained ice-covered throughout the Holocene. Just before the life of the Iceman, high Alpine summits were emerging from nearly ice-free conditions, during the start of a Mid-Holocene neoglaciation. We demonstrate that, under specific circumstances, the old ice at the base of high Alpine glaciers is a sensitive archive of glacier change. However, under current melt rates the archive at Weißseespitze and at similar locations will be lost within the next two decades.

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