scholarly journals Plant communities as drivers of soil respiration: pathways, mechanisms, and significance for global change

2011 ◽  
Vol 8 (8) ◽  
pp. 2047-2061 ◽  
Author(s):  
D. B. Metcalfe ◽  
R. A. Fisher ◽  
D. A. Wardle
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Plant Traits ◽  
Terrestrial Ecosystems ◽  
Climate Impacts ◽  
Individual Species ◽  
Global Changes ◽  
Individual Plant ◽  
Vegetation Types ◽  
Species Invasions

Abstract. Understanding the impacts of plant community characteristics on soil carbon dioxide efflux (R) is a key prerequisite for accurate prediction of the future carbon (C) balance of terrestrial ecosystems under climate change. However, developing a mechanistic understanding of the determinants of R is complicated by the presence of multiple different sources of respiratory C within soil – such as soil microbes, plant roots and their mycorrhizal symbionts – each with their distinct dynamics and drivers. In this review, we synthesize relevant information from a wide spectrum of sources to evaluate the current state of knowledge about plant community effects on R, examine how this information is incorporated into global climate models, and highlight priorities for future research. Despite often large variation amongst studies and methods, several general trends emerge. Mechanisms whereby plants affect R may be grouped into effects on belowground C allocation, aboveground litter properties and microclimate. Within vegetation types, the amount of C diverted belowground, and hence R, may be controlled mainly by the rate of photosynthetic C uptake, while amongst vegetation types this should be more dependent upon the specific C allocation strategies of the plant life form. We make the case that plant community composition, rather than diversity, is usually the dominant control on R in natural systems. Individual species impacts on R may be largest where the species accounts for most of the biomass in the ecosystem, has very distinct traits to the rest of the community and/or modulates the occurrence of major natural disturbances. We show that climate vegetation models incorporate a number of pathways whereby plants can affect R, but that simplifications regarding allocation schemes and drivers of litter decomposition may limit model accuracy. We also suggest that under a warmer future climate, many plant communities may shift towards dominance by fast growing plants which produce large quantities of nutrient rich litter. Where this community shift occurs, it could drive an increase in R beyond that expected from direct climate impacts on soil microbial activity alone. We identify key gaps in knowledge and recommend them as priorities for future work. These include the patterns of photosynthate partitioning amongst belowground components, ecosystem level effects of individual plant traits, and the importance of trophic interactions and species invasions or extinctions for ecosystem processes. A final, overarching challenge is how to link these observations and drivers across spatio-temporal scales to predict regional or global changes in R over long time periods. A more unified approach to understanding R, which integrates information about plant traits and community dynamics, will be essential for better understanding, simulating and predicting patterns of R across terrestrial ecosystems and its role within the earth-climate system.

scholarly journals Plant communities as drivers of soil respiration: pathways, mechanisms, and significance for global change

2011 ◽  
Vol 8 (2) ◽  
pp. 2145-2181
Author(s):  
D. B. Metcalfe ◽  
R. A. Fisher ◽  
D. A. Wardle
Keyword(s):  
Climate Change ◽  
Plant Community ◽  
Plant Traits ◽  
Terrestrial Ecosystems ◽  
Ecosystem Processes ◽  
Life History Strategies ◽  
Individual Species ◽  
Individual Plant ◽  
Vegetation Types ◽  
Species Invasions

Abstract. Understanding the impacts of plant community characteristics on soil carbon dioxide efflux (R) is a key prerequisite for accurate prediction of the future carbon balance of terrestrial ecosystems under climate change. In this review, we synthesize relevant information from a wide spectrum of sources to evaluate the current state of knowledge about plant community effects on R, examine how this information is incorporated into global climate models, and highlight priorities for future research. Plant species consistently exhibit cohesive suites of traits, linked to contrasting life history strategies, which exert a variety of impacts on R. As such, we propose that plant community shifts towards dominance by fast growing plants with nutrient rich litter could provide a major, though often neglected, positive feedback to climate change. Within vegetation types, belowground carbon flux will mainly be controlled by photosynthesis, while amongst vegetation types this flux will be more dependent upon the specific characteristics of the plant life form. We also make the case that community composition, rather than diversity, is usually the dominant control on ecosystem processes in natural systems. Individual species impacts on R may be largest where the species accounts for most of the biomass in the ecosystem, has very distinct traits to the rest of the community, or modulates the occurrence of major natural disturbances. We show that climate-vegetation models incorporate a number of pathways whereby plants can affect R, but that simplifications regarding allocation schemes and drivers of litter decomposition may limit model accuracy. This situation could, however, be relatively easily improved with targeted experimental and field studies. Finally, we identify key gaps in knowledge and recommend them as priorities for future work. These include the patterns of photosynthate partitioning amongst belowground components, ecosystem level effects of individual plant traits, and the importance of trophic interactions and species invasions or extinctions for ecosystem processes. A final, overarching challenge is how to link these observations and drivers across spatio-temporal scales to predict regional or global changes in R over long time periods. A more unified approach to understanding R, which integrates information about plant traits and community dynamics, will be essential for better understanding, simulating and predicting feedbacks to R across terrestrial ecosystems and the earth-climate system.

scholarly journals Microbial community response to a decade of simulated global changes depends on the plant community

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sarai S. Finks ◽  
Claudia Weihe ◽  
Sarah Kimball ◽  
Steven D. Allison ◽  
Adam C. Martiny ◽  
...  
Keyword(s):  
Global Change ◽  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Bacterial Community Composition ◽  
Community Response ◽  
Plant Litter ◽  
Global Changes ◽  
Dependent Manner ◽  
Microbial Composition

Global changes such as increased drought and atmospheric nitrogen deposition perturb both the microbial and plant communities that mediate terrestrial ecosystem functioning. However, few studies consider how microbial responses to global changes may be influenced by interactions with plant communities. To begin to address the role of microbial–plant interactions, we tested the hypothesis that the response of microbial communities to global change depends on the plant community. We characterized bacterial and fungal communities from 395 plant litter samples taken from the Loma Ridge Global Change Experiment, a decade-long global change experiment in Southern California that manipulates rainfall and nitrogen levels across two adjacent ecosystems, a grassland and a coastal sage scrubland. The differences in bacterial and fungal composition between ecosystems paralleled distinctions in plant community composition. In addition to the direct main effects, the global change treatments altered microbial composition in an ecosystem-dependent manner, in support of our hypothesis. The interaction between the drought treatment and ecosystem explained nearly 5% of the variation in bacterial community composition, similar to the variation explained by the ecosystem-independent effects of drought. Unexpectedly, we found that the main effect of drought was approximately four times as strong on bacterial composition as that of nitrogen addition, which did not alter fungal or plant composition. Overall, the findings underscore the importance of considering plant–microbe interactions when considering the transferability of the results of global change experiments across ecosystems.

Predicting fire-based perennial bunchgrass mortality in big sagebrush plant communities

2015 ◽  
Vol 24 (4) ◽  
pp. 527 ◽  
Author(s):  
Chad S. Boyd ◽  
Kirk W. Davies ◽  
April Hulet
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Perennial Grass ◽  
Basal Area ◽  
Grass Species ◽  
Individual Plant ◽  
Ecological Sites ◽  
Big Sagebrush ◽  
Ecological Site ◽  
Fire Characteristics

Maintenance and post-fire rehabilitation of perennial bunchgrasses is important for reducing the spread of exotic annual grass species in big sagebrush plant communities. Post-fire rehabilitation decisions are hampered by a lack of tools for determining extent of fire-induced perennial grass mortality. Our objective was to correlate post-fire characteristics with perennial bunchgrass mortality at the plant and plant community scales. We recorded basal area, percent char, depth of burn and soil colour for 174 bunchgrasses across four ecological sites after a 65 000 ha wildfire in south-east Oregon and assessed plant mortality. Mortality was correlated with post-fire soil colour and ecological site; soil colours (black and grey) associated with pre-fire shrub presence had up to five-fold higher mortality than brown soils typical of interspace locations. Models incorporating depth of burn and soil colour correctly predicted mortality for 90% of individual plants; cover of brown soil explained 88% of the variation in bunchgrass mortality at the plant community scale. Our results indicate that soil colour and depth of burn are accurate predictors of bunchgrass mortality at individual plant and plant community scales and could be used to spatially allocate post-fire bunchgrass rehabilitation resources.

scholarly journals Practice Must Be Backed up by Theory! A Special Issue on Plant Community Ecology

Diversity ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 438
Author(s):  
Giovanni Bacaro ◽  
Simona Maccherini ◽  
Michela Marignani
Keyword(s):  
Community Ecology ◽  
Plant Community ◽  
Plant Communities ◽  
Terrestrial Ecosystems ◽  
Special Issue ◽  
Plant Community Ecology ◽  
Functional Basis

Plant communities form the structural and functional basis for nearly all terrestrial ecosystems [...]

scholarly journals Spatial Patterns in Plant Diversity

2021 ◽  
Author(s):  
◽  
Danilo Coelho de Almeida
Keyword(s):  
New Zealand ◽  
Plant Community ◽  
Plant Communities ◽  
Environmental Conditions ◽  
Species Abundance ◽  
Principal Component ◽  
Null Models ◽  
Individual Species ◽  
Leaf Mass Per Area ◽  
Mature Trees

<p>The present study is divided into two parts: Firstly, null models where used to test whether plant communities in a New Zealand forest were assembled deterministically or stochastically. Secondly, a relationship between a plant trait; Leaf Mass per Area (LMA) and environmental conditions was investigated in a New Zealand forest. For the first study abundance of adult species was recorded in thirty 30m x 30m plots at Otari Wilton's Bush. In a subsample of six plots, the abundance of seedling species was also recorded. Null models for species co-occurrence, species richness, species abundance and niche overlap were used in order to establish how plant communities assemble at Otari Wilton's Bush. There was evidence of both determinist and stochasticity in some aspects of the plant community, it appears that seedlings are mainly randomly assembled whereas, determinism appears to be the main driver of community composition for mature trees. Results therefore suggest a pluralistic approach should be used in order to explain plant community patterns at Otari Wilton's Bush. For the second study, of all species observed in the first study only those species found in five or more of the plots were examined. For those species, the height of the two highest individuals was measured. From each individual, six fully exposed leaves were collected and measured. Measurements of environmental conditions were also collected for all plots. Principal component analysis and multiple regression was used to analyse the data. Height related (vertical) trends were observed for three surveyed species such that LMA significantly increased with plant height. Horizontal patterns were observed for two species, and for three species it was not possible to distinguish the association of tree height (vertical) and position along the forest (horizontal) with LMA. Potentially, by including more species in future studies a clearer pattern will be observed. It could also be that different species display different strategies regarding LMA and if so, a study more focused on individual species in isolation may be able to provide more informative explanations.</p>

Patterns of flammability of the California oaks: the role of leaf traits

2012 ◽  
Vol 42 (11) ◽  
pp. 1965-1975 ◽  
Author(s):  
Eamon A. Engber ◽  
J. Morgan Varner
Keyword(s):  
Plant Traits ◽  
Fire Regime ◽  
Fire Behavior ◽  
Volume Ratio ◽  
Leaf Size ◽  
Fire Regimes ◽  
Individual Species ◽  
Individual Plant ◽  
Leaf Margin ◽  
Data Set

Fire is one of the most important processes driving plant community composition and structure. Fire regimes are largely governed by climate, vegetation structure, and individual plant traits that influence flammability. We assessed the mechanistic drivers of flammability for a diverse group of 18 California Quercus and allied Chrysolepis and Notholithocarpus species, addressing variation in leaf physical traits, growth form (tree or shrub), phylogeny (Quercus subgenera), and fire regime (low, mixed, or high severity). Differences in flammability were not strongly driven by leaf habit, leaf margin type, or surface area to volume ratio; simple measures of leaf size accounted for most of the observed variation. Further, leaf size was tightly linked to fuelbed depth, a known driver of fire behavior. Litter from trees was generally more flammable than litter from shrubs, primarily a function of differences in leaf size. A hierarchical clustering analysis on the flammability data set divided the oaks into three clusters of low, intermediate, and high flammability, corresponding closely to high-, mixed-, and low-severity fire regimes, respectively. The link between plant flammability traits and fire regime provides further evidence that individual species affect ecosystem processes.

scholarly journals Plant community composition, not diversity, regulates soil respiration in grasslands

2008 ◽  
Vol 4 (4) ◽  
pp. 345-348 ◽  
Author(s):  
David Johnson ◽  
Gareth K Phoenix ◽  
J. Philip Grime
Keyword(s):  
Soil Respiration ◽  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Functional Group ◽  
Plant Biomass ◽  
Terrestrial Ecosystems ◽  
Plant Species Richness ◽  
Plant Community Composition ◽  
Respiration Rates

Soil respiration is responsible for recycling considerable quantities of carbon from terrestrial ecosystems to the atmosphere. There is a growing body of evidence that suggests that the richness of plants in a community can have significant impacts on ecosystem functioning, but the specific influences of plant species richness (SR), plant functional-type richness and plant community composition on soil respiration rates are unknown. Here we use 10-year-old model plant communities, comprising mature plants transplanted into natural non-sterile soil, to determine how the diversity and composition of plant communities influence soil respiration rates. Our analysis revealed that soil respiration was driven by plant community composition and that there was no significant effect of biodiversity at the three levels tested (SR, functional group and species per functional group). Above-ground plant biomass and root density were included in the analysis as covariates and found to have no effect on soil respiration. This finding is important, because it suggests that loss of particular species will have the greatest impact on soil respiration, rather than changes in biodiversity per se .

scholarly journals Spatial Patterns in Plant Diversity

2021 ◽  
Author(s):  
◽  
Danilo Coelho de Almeida
Keyword(s):  
New Zealand ◽  
Plant Community ◽  
Plant Communities ◽  
Environmental Conditions ◽  
Species Abundance ◽  
Principal Component ◽  
Null Models ◽  
Individual Species ◽  
Leaf Mass Per Area ◽  
Mature Trees

<p>The present study is divided into two parts: Firstly, null models where used to test whether plant communities in a New Zealand forest were assembled deterministically or stochastically. Secondly, a relationship between a plant trait; Leaf Mass per Area (LMA) and environmental conditions was investigated in a New Zealand forest. For the first study abundance of adult species was recorded in thirty 30m x 30m plots at Otari Wilton's Bush. In a subsample of six plots, the abundance of seedling species was also recorded. Null models for species co-occurrence, species richness, species abundance and niche overlap were used in order to establish how plant communities assemble at Otari Wilton's Bush. There was evidence of both determinist and stochasticity in some aspects of the plant community, it appears that seedlings are mainly randomly assembled whereas, determinism appears to be the main driver of community composition for mature trees. Results therefore suggest a pluralistic approach should be used in order to explain plant community patterns at Otari Wilton's Bush. For the second study, of all species observed in the first study only those species found in five or more of the plots were examined. For those species, the height of the two highest individuals was measured. From each individual, six fully exposed leaves were collected and measured. Measurements of environmental conditions were also collected for all plots. Principal component analysis and multiple regression was used to analyse the data. Height related (vertical) trends were observed for three surveyed species such that LMA significantly increased with plant height. Horizontal patterns were observed for two species, and for three species it was not possible to distinguish the association of tree height (vertical) and position along the forest (horizontal) with LMA. Potentially, by including more species in future studies a clearer pattern will be observed. It could also be that different species display different strategies regarding LMA and if so, a study more focused on individual species in isolation may be able to provide more informative explanations.</p>

scholarly journals Global change effects on plant communities are magnified by time and the number of global change factors imposed

2019 ◽  
Vol 116 (36) ◽  
pp. 17867-17873 ◽  
Author(s):  
Kimberly J. Komatsu ◽  
Meghan L. Avolio ◽  
Nathan P. Lemoine ◽  
Forest Isbell ◽  
Emily Grman ◽  
...  
Keyword(s):  
Community Structure ◽  
Global Change ◽  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Human Activities ◽  
Global Changes ◽  
Herbaceous Plant ◽  
Community Responses ◽  
Similar Frequency

Global change drivers (GCDs) are expected to alter community structure and consequently, the services that ecosystems provide. Yet, few experimental investigations have examined effects of GCDs on plant community structure across multiple ecosystem types, and those that do exist present conflicting patterns. In an unprecedented global synthesis of over 100 experiments that manipulated factors linked to GCDs, we show that herbaceous plant community responses depend on experimental manipulation length and number of factors manipulated. We found that plant communities are fairly resistant to experimentally manipulated GCDs in the short term (<10 y). In contrast, long-term (≥10 y) experiments show increasing community divergence of treatments from control conditions. Surprisingly, these community responses occurred with similar frequency across the GCD types manipulated in our database. However, community responses were more common when 3 or more GCDs were simultaneously manipulated, suggesting the emergence of additive or synergistic effects of multiple drivers, particularly over long time periods. In half of the cases, GCD manipulations caused a difference in community composition without a corresponding species richness difference, indicating that species reordering or replacement is an important mechanism of community responses to GCDs and should be given greater consideration when examining consequences of GCDs for the biodiversity–ecosystem function relationship. Human activities are currently driving unparalleled global changes worldwide. Our analyses provide the most comprehensive evidence to date that these human activities may have widespread impacts on plant community composition globally, which will increase in frequency over time and be greater in areas where communities face multiple GCDs simultaneously.

scholarly journals Cost-benefit Quantification of Leaf Carbon Economics to Disentangle Responses of Plant Assemblages to Deer Herbivory

2021 ◽  
Author(s):  
Yuki Wakatsuki ◽  
Keita Nishizawa ◽  
Akira S Mori
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Dominance Rank ◽  
Cost Benefit ◽  
Forest Understory ◽  
Individual Plant ◽  
Plant Community Composition ◽  
Carbon Cost ◽  
Deer Herbivory

Abstract Although the plant carbon cost-benefit balance is known to be related to individual plant growth, reproduction, and population expansion, the association with plant community differences is not well understood. In this study, we examined how the leaf carbon cost-benefit metrics were associated with the assembly process of forest understory plant communities in areas highly affected by deer browsing. We calculated these metrics from plant physiologically parameters for 14 forest floor plant species growing in deer presence/absence site to detect the relationship between species dominance and leaf carbon cost-benefit metrics. As a result, the patterns of interspecific variation in benefit along the plant dominance rank differed in deer presence/absence sites, contributing to the marked differences in species composition and diversity observed at the two sites. In the absence of deer, where competition was the dominant determinant of plant community composition, carbon benefits among species were positively related to the plant dominance rank, indicating that species able to acquire more carbon were at an advantage. On the other hand, under deer herbivory, differences in carbon benefit between species were not strongly apparent and were not related to the plant dominance rank, indicating few differences in reproductive and expansion ability (plant fitness) between species. This process contributes to the high species diversity of plant communities observed in the presence of deer. Our results emphasize the possibility of connecting different fields of studies, physiological ecology, community ecology, and the plant carbon cost-benefit balance of single leaves to explain plant community composition differences.

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