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 Resource availability is much more important than resource heterogeneity in determining the species diversity and abundance of karst plant communities

2021 ◽  
Author(s):  
Yuan LIU ◽  
Wenchao Qi ◽  
Danni He ◽  
Yunrong Xiang ◽  
Jin Chun Liu ◽  
...  
Keyword(s):  
Species Diversity ◽  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Resource Availability ◽  
Structural Equation ◽  
Variation Partitioning ◽  
Equation Model ◽  
Plant Community Composition ◽  
Resource Heterogeneity

Resource availability and heterogeneity are recognized as two essential environmental aspects to determine species diversity and community abundance. However, how resource availability and heterogeneity determine species diversity and community abundance in highly heterogeneous and most fragile karst landscapes is largely unknown. We examined the effects of resource availability and heterogeneity on plant community composition and quantified their relative contribution by variation partitioning. Then, a structural equation model (SEM) was used to further disentangle the multiple direct and indirect effects of resource availability on plant community composition. Species diversity was significantly influenced by the resource availability in shrubland and woodland but not by the heterogeneity in woodland. Abundance was significantly affected by both resource availability and heterogeneity, whereas variation partitioning results showed that resource availability explained the majority of the variance in abundance, and the contribution of resource heterogeneity was marginal. These results indicated that resource availability plays a more important role in determining karst plant community composition than resource heterogeneity. Our SEMs further found that the multiple direct and indirect processes of resource availability in determining karst species diversity and abundance were different in different vegetation types. Resource availability and heterogeneity both played a certain role in determining karst plant community composition, while the importance of resource availability far exceeded resource heterogeneity. We propose that steering community restoration and reconstruction should be highly dependent on resource availability, and multiple direct and indirect pathways of resource availability for structuring karst plant communities need to be taken into account.

scholarly journals The invasive herb Lupinus polyphyllus can reduce plant species richness independently of local invasion age

2021 ◽  
Author(s):  
Marju Prass ◽  
Satu Ramula ◽  
Miia Jauni ◽  
Heikki Setälä ◽  
D. Johan Kotze
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Plant Community ◽  
Plant Communities ◽  
Vascular Plant ◽  
Plant Species Richness ◽  
Ecological Impacts ◽  
Plant Community Composition ◽  
Lupinus Polyphyllus ◽  
Local Invasion

AbstractThe ecological impacts of invasive species may change or accumulate with time since local invasion, potentially inducing further changes in communities and the abiotic environment. Yet, time since invasion is rarely considered when investigating the ecological impacts of invasive non-native species. To examine the effect of time since invasion on the ecological impacts of Lupinus polyphyllus, a perennial nitrogen-fixing herb, we surveyed vascular plant communities in the presence and absence of L. polyphyllus in young, intermediate, and old semi-natural grassland sites (ca. 5, 10, 15 years representing both time since lupine invasion and plant community age). We analyzed vascular plant community composition, vascular plant species richness, and the cover of various ecological plant groups and L. polyphyllus. In contrast to our hypotheses, we found no change in the mean cover of L. polyphyllus (about 35%) with time since local invasion, and an ordination did not suggest marked changes in plant community composition. L. polyphyllus was associated with lower species richness in invaded plant communities but this effect did not change with time since invasion. Invaded plant communities were also associated with lower occurrence of generalist, oligotrophic (low-nutrient-adapted) and copiotrophic (nutrient-demanding) species but no temporal dynamics were detected. We conclude that even the intermediate cover of L. polyphyllus can reduce plant species richness, but the ecological impact caused by this invader might not dramatically change or accumulate with time since invasion.

scholarly journals Short-term climate-induced change in French plant communities

2019 ◽  
Vol 15 (7) ◽  
pp. 20190280 ◽  
Author(s):  
Gabrielle Martin ◽  
Vincent Devictor ◽  
Eric Motard ◽  
Nathalie Machon ◽  
Emmanuelle Porcher
Keyword(s):  
Climate Change ◽  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Thermal Preference ◽  
Plant Community Composition ◽  
Large Area ◽  
High Dispersal ◽  
Short Period ◽  
The Impact

Latitudinal and altitudinal range shifts in response to climate change have been reported for numerous animal species, especially those with high dispersal capacities. In plants, the impact of climate change on species distribution or community composition has been documented mainly over long periods (decades) and in specific habitats, often forests. Here, we broaden the results of such long-term, focused studies by examining climate-driven changes in plant community composition over a large area (France) encompassing multiple habitat types and over a short period (2009–2017). To this end, we measured mean community thermal preference, calculated as the community-weighted mean of the Ellenberg temperature indicator value, using data from a standardized participatory monitoring scheme. We report a rapid increase in the mean thermal preference of plant communities at national and regional scales, which we relate to climate change. This reshuffling of plant community composition corresponds to a relative increase in the abundance of warm- versus cold-adapted species. However, support for this trend was weaker when considering only the common species, including common annuals. Our results thus suggest for the first time that the response of plant communities to climate change involves subtle changes affecting all species rare and common, which can nonetheless be detected over short time periods. Whether such changes are sufficient to cope with the current climate warming remains to be ascertained.

Zonation of vegetation along a burial gradient on the leeward slopes of Lake Huron sand dunes

2005 ◽  
Vol 83 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Jeffery P Dech ◽  
M Anwar Maun
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Sand Dunes ◽  
Salt Spray ◽  
Coastal Dunes ◽  
Causative Factor ◽  
Lake Huron ◽  
Plant Community Composition ◽  
Species Importance

The zonation of coastal dune plant communities from the beach to their inland margin is recognized worldwide; however, the cause of this pattern remains controversial because of the covariance of several environmental factors, such as sand burial, salt spray, and microclimate, along a gradient perpendicular to the shoreline. To minimize the confounding influence of this complex shore–inland gradient and determine the direct effects of burial on plant community composition, we examined stands along a burial gradient that extended parallel to the Lake Huron coastline, produced by variable blowout activity amongst a series of parabolic dunes comprising the second ridge inland from the coast. We used the point-quarter method and 1 m × 1 m plots to quantify overstorey and understorey plant communities in each parabolic dune stand and determined species importance, here defined as the sum of density, frequency, and dominance for the overstorey and the sum of frequency and dominance only for the understorey. Correspondence analyses of the species importance – dune stand matrices elucidated a pattern of plant community composition on the primary ordination axis that was strongly related to an index of burial activity (r2 = 0.40 and 0.87 for the overstorey and understorey, respectively). Burial was associated with changes in species richness and diversity, shifts in dominant species, and species replacement based on burial tolerance across the gradient. These data support the hypothesis that burial in sand dunes is a major causative factor of zonation, which can extend beyond the foredunes and include communities of woody species.Key words: coastal dunes, vegetation, zonation, woody plants, burial.

scholarly journals Livestock grazing-induced large-scale biotic homogenization in arid Mediterranean steppe rangelands

2021 ◽  
Author(s):  
Merdas Saifi ◽  
Yacine Kouba ◽  
Tewfik Mostephaoui ◽  
Yassine Farhi ◽  
Haroun Chenchouni
Keyword(s):  
Species Composition ◽  
Spatial Scale ◽  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Beta Diversity ◽  
Large Scale ◽  
Livestock Grazing ◽  
Plant Community Composition ◽  
Arid Steppe

Despite many studies explored the effect of livestock grazing on plant communities the response of species composition and diversity to livestock grazing in arid rangelands remain ambiguous. This study examined the effects of livestock grazing vs grazing exclusion on plant communities in arid steppe rangelands of North Africa. Plant diversity of annual species perennial species and all species combined was measured and compared between grazed and grazing-excluded areas. We also verified whether the difference in plant community composition between the two management types was due to species spatial turnover or community nestedness. Besides the effects of livestock grazing on beta diversity at local among transects and landscape among sites scales were examined using the multiplicative diversity partitioning. Results revealed that livestock grazing significantly decreased the alpha diversity of all species combined and the diversity of annual plants. Livestock grazing induced a shift in plant community composition where the most of species composition variation ~74% was due to infrequent species replacement between the two management types rather than community sub setting ~26%. The analysis of beta diversity at different spatial scales revealed that livestock grazing significantly increased beta diversity at the local scale but decreased it at the landscape scale. Our findings suggest that livestock grazing in arid steppe rangelands increases the variation of plant composition at local spatial scale and engenders vegetation homogeneity at coarse spatial scale. Therefore, the implementation of appropriate management practices such as short-term grazing exclusion is mandatory to prevent these ecosystems from large scale biotic homogenization.

scholarly journals Warming increases soil respiration in a carbon-rich soil without changing microbial respiratory potential

2020 ◽  
Author(s):  
Marion Nyberg ◽  
Mark J. Hovenden
Keyword(s):  
Soil Respiration ◽  
Community Composition ◽  
Plant Community ◽  
Climate Feedback ◽  
Co2 Efflux ◽  
Plant Community Composition ◽  
Soil C ◽  
Incubation Experiments ◽  
C Stocks ◽  
Respiratory Potential

Abstract. Increases in global temperatures due to climate change threaten to tip the balance between carbon (C) fluxes, liberating large amounts of C from soils. Evidence of warming-induced increases in CO2 efflux from soils has led to suggestions that this response of soil respiration (Rs) will trigger a positive land C–climate feedback cycle, ultimately warming the earth further. Currently, there is little consensus about the mechanisms driving the warming-induced Rs response, and there are relatively few studies from ecosystems with large soil C stores. Here, we investigate the impacts of experimental warming on Rs in the C-rich soils of a Tasmanian grassy sedgeland, and whether alterations of plant community composition or differences in microbial respiratory potential could contribute to any effects. In situ, warming increased Rs on average by 28 % and this effect was consistent over time and across plant community composition treatments. In contrast, warming had no impact on microbial respiration in incubation experiments. Plant community composition manipulations did not influence Rs or the Rs response to warming. Processes driving the Rs response in this experiment were, therefore, not due plant community effects and are more likely due to increases in belowground autotrophic respiration and the supply of labile substrate through rhizodeposition and root exudates. CO2 efflux from this high-C soil increased by more than a quarter in response to warming, suggesting inputs need to increase by at least this amount if soil C stocks are to be maintained. These results indicate the need for comprehensive investigations of both C inputs and losses from C-rich soils if efforts to model net ecosystem C exchange of these crucial, C-dense systems are to be successful.

scholarly journals Warming increases soil respiration in a carbon-rich soil without changing microbial respiratory potential

2020 ◽  
Vol 17 (17) ◽  
pp. 4405-4420
Author(s):  
Marion Nyberg ◽  
Mark J. Hovenden
Keyword(s):  
Soil Respiration ◽  
Community Composition ◽  
Plant Community ◽  
Climate Feedback ◽  
Co2 Efflux ◽  
Plant Community Composition ◽  
Soil C ◽  
C Stocks ◽  
Below Ground ◽  
Respiratory Potential

Abstract. Increases in global temperatures due to climate change threaten to tip the balance between carbon (C) fluxes, liberating large amounts of C from soils. Evidence of warming-induced increases in CO2 efflux from soils has led to suggestions that this response of soil respiration (RS) will trigger a positive land C–climate feedback cycle, ultimately warming the Earth further. Currently, there is little consensus about the mechanisms driving the warming-induced RS response, and there are relatively few studies from ecosystems with large soil C stores. Here, we investigate the impacts of experimental warming on RS in the C-rich soils of a Tasmanian grassy sedgeland and whether alterations of plant community composition or differences in microbial respiratory potential could contribute to any effects. In situ, warming increased RS on average by 28 %, and this effect was consistent over time and across plant community composition treatments. In contrast, warming had no impact on microbial respiration in incubation experiments. Plant community composition manipulations did not influence RS or the RS response to warming. Processes driving the RS response in this experiment were, therefore, not due to plant community effects and are more likely due to increases in below-ground autotrophic respiration and the supply of labile substrate through rhizodeposition and root exudates. CO2 efflux from this high-C soil increased by more than a quarter in response to warming, suggesting inputs need to increase by at least this amount if soil C stocks are to be maintained. These results indicate the need for comprehensive investigations of both C inputs and losses from C-rich soils if efforts to model net ecosystem C exchange of these crucial, C-dense systems are to be successful.

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