Coupling spectral and resource-use complementarity in experimental grassland and forest communities

Reflectance spectra provide integrative measures of plant phenotypes by capturing chemical, morphological, anatomical and architectural trait information. Here, we investigate the linkages between plant spectral variation, and spectral and resource-use complementarity that contribute to ecosystem productivity. In both a forest and prairie grassland diversity experiment, we delineated n -dimensional hypervolumes using wavelength bands of reflectance spectra to test the association between the spectral space occupied by individual plants and their growth, as well as between the spectral space occupied by plant communities and ecosystem productivity. We show that the spectral space occupied by individuals increased with their growth, and the spectral space occupied by plant communities increased with ecosystem productivity. Furthermore, ecosystem productivity was better explained by inter-individual spectral complementarity than by the large spectral space occupied by productive individuals. Our results indicate that spectral hypervolumes of plants can reflect ecological strategies that shape community composition and ecosystem function, and that spectral complementarity can reveal resource-use complementarity.

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Temporal dynamics of mycorrhizal fungal communities and co-associations with grassland plant communities following experimental manipulation of rainfall

10.32942/osf.io/t82ug ◽

2019 ◽

Cited By ~ 1

Author(s):

Coline Deveautour ◽

Sally Power ◽

Kirk Barnett ◽

Raul Ochoa-Hueso ◽

Suzanne Donn ◽

...

Keyword(s):

Community Composition ◽

Plant Community ◽

Plant Communities ◽

Fungal Community ◽

Mycorrhizal Fungi ◽

Temporal Dynamics ◽

Arbuscular Mycorrhizal ◽

Fungal Communities ◽

Plant Responses ◽

Rainfall Regimes

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.

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Towards a function-first framework to make soil microbial ecology predictive

10.5194/egusphere-egu21-14139 ◽

2021 ◽

Author(s):

Johannes Rousk ◽

Lettice Hicks

Keyword(s):

Microbial Community ◽

Environmental Factors ◽

Microbial Communities ◽

Functional Response ◽

Community Composition ◽

Ecosystem Function ◽

Bacterial Growth ◽

Response Curve ◽

Ecosystem Functions ◽

Soil Microbial

Soil microbial communities perform vital ecosystem functions, such as the decomposition of organic matter to provide plant nutrition. However, despite the functional importance of soil microorganisms, attribution of ecosystem function to particular constituents of the microbial community has been impeded by a lack of information linking microbial function to community composition and structure. Here, we propose a function-first framework to predict how microbial communities influence ecosystem functions.We first view the microbial community associated with a specific function as a whole, and describe the dependence of microbial functions on environmental factors (e.g. the intrinsic temperature dependence of bacterial growth rates). This step defines the aggregate functional response curve of the community. Second, the contribution of the whole community to ecosystem function can be predicted, by combining the functional response curve with current environmental conditions. Functional response curves can then be linked with taxonomic data in order to identify sets of &#8220;biomarker&#8221; taxa that signal how microbial communities regulate ecosystem functions. Ultimately, such indicator taxa may be used as a diagnostic tool, enabling predictions of ecosystem function from community composition.In this presentation, we provide three examples to illustrate the proposed framework, whereby the dependence of bacterial growth on environmental factors, including temperature, pH and salinity, is defined as the functional response curve used to interlink soil bacterial community structure and function. Applying this framework will make it possible to predict ecosystem functions directly from microbial community composition.

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Effects of nitrogen enrichment on zooplankton biomass and N:P recycling ratios across a DOC gradient in northern-latitude lakes

Hydrobiologia ◽

10.1007/s10750-021-04689-5 ◽

2021 ◽

Author(s):

A.-K. Bergström ◽

A. Deininger ◽

A. Jonsson ◽

J. Karlsson ◽

T. Vrede

Keyword(s):

Community Composition ◽

Resource Use ◽

Phytoplankton Biomass ◽

Phytoplankton Community ◽

N Fertilization ◽

Zooplankton Biomass ◽

Nitrogen Enrichment ◽

C:N:P Stoichiometry ◽

Food Quantity ◽

N Enrichment

AbstractWe used data from whole-lake studies to assess how changes in food quantity (phytoplankton biomass) and quality (phytoplankton community composition, seston C:P and N:P) with N fertilization affect zooplankton biomass, community composition and C:N:P stoichiometry, and their N:P recycling ratio along a gradient in lake DOC concentrations. We found that despite major differences in phytoplankton biomass with DOC (unimodal distributions, especially with N fertilization), no major differences in zooplankton biomass were detectable. Instead, phytoplankton to zooplankton biomass ratios were high, especially at intermediate DOC and after N fertilization, implying low trophic transfer efficiencies. An explanation for the observed low phytoplankton resource use, and biomass responses in zooplankton, was dominance of colony forming chlorophytes of reduced edibility at intermediate lake DOC, combined with reduced phytoplankton mineral quality (enhanced seston N:P) with N fertilization. N fertilization, however, increased zooplankton N:P recycling ratios, with largest impact at low DOC where phytoplankton benefitted from light sufficiently to cause enhanced seston N:P. Our results suggest that although N enrichment and increased phytoplankton biomass do not necessarily increase zooplankton biomass, bottom-up effects may still impact zooplankton and their N:P recycling ratio through promotion of phytoplankton species of low edibility and altered mineral quality.

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Plant and insect herbivore community variation across the Paleocene–Eocene boundary in the Hanna Basin, southeastern Wyoming

PeerJ ◽

10.7717/peerj.7798 ◽

2019 ◽

Vol 7 ◽

pp. e7798

Author(s):

Lauren E. Azevedo Schmidt ◽

Regan E. Dunn ◽

Jason Mercer ◽

Marieke Dechesne ◽

Ellen D. Currano

Keyword(s):

Community Composition ◽

Plant Communities ◽

Plant Diversity ◽

High Water ◽

Insect Herbivore ◽

Herbivore Damage ◽

Late Paleocene ◽

Hanna Basin ◽

Laramide Basins ◽

Herbivore Communities

Ecosystem function and stability are highly affected by internal and external stressors. Utilizing paleobotanical data gives insight into the evolutionary processes an ecosystem undergoes across long periods of time, allowing for a more complete understanding of how plant and insect herbivore communities are affected by ecosystem imbalance. To study how plant and insect herbivore communities change during times of disturbance, we quantified community turnover across the Paleocene–Eocene boundary in the Hanna Basin, southeastern Wyoming. This particular location is unlike other nearby Laramide basins because it has an abundance of late Paleocene and Eocene coal and carbonaceous shales and paucity of well-developed paleosols, suggesting perpetually high water availability. We sampled approximately 800 semi-intact dicot leaves from five stratigraphic levels, one of which occurs late in the Paleocene–Eocene thermal maximum (PETM). Field collections were supplemented with specimens at the Denver Museum of Nature & Science. Fossil leaves were classified into morphospecies and herbivore damage was documented for each leaf. We tested for changes in plant and insect herbivore damage diversity using rarefaction and community composition using non-metric multidimensional scaling ordinations. We also documented changes in depositional environment at each stratigraphic level to better contextualize the environment of the basin. Plant diversity was highest during the mid-late Paleocene and decreased into the Eocene, whereas damage diversity was highest at the sites with low plant diversity. Plant communities significantly changed during the late PETM and do not return to pre-PETM composition. Insect herbivore communities also changed during the PETM, but, unlike plant communities, rebound to their pre-PETM structure. These results suggest that insect herbivore communities responded more strongly to plant community composition than to the diversity of species present.

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When Competition Does Not Matter: Grassland Diversity and Community Composition

The American Naturalist ◽

10.1086/587528 ◽

2008 ◽

Vol 171 (6) ◽

pp. 777-787 ◽

Cited By ~ 74

Author(s):

Eric G. Lamb ◽

James F. Cahill Jr.

Keyword(s):

Community Composition ◽

Grassland Diversity

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Disturbing to restore? Effects of mounding on understory communities on seismic lines in treed peatlands

Canadian Journal of Forest Research ◽

10.1139/cjfr-2020-0092 ◽

2020 ◽

Vol 50 (12) ◽

pp. 1340-1351

Author(s):

Laureen F.I. Echiverri ◽

S. Ellen Macdonald ◽

Scott E. Nielsen

Keyword(s):

Community Composition ◽

Plant Communities ◽

Oil And Gas ◽

Reference Sites ◽

Oil And Gas Exploration ◽

Understory Plant ◽

Understory Plant Communities ◽

Understory Communities ◽

Associated Species ◽

Seismic Lines

In peatlands, microtopography strongly affects understory plant communities. Disturbance can result in a loss of microtopographic variation, primarily through the loss of hummocks. To address this, mounding treatments can be used to restore microtopography. We examined the effects of mounding on the understory vegetation on seismic lines in wooded fens. Seismic lines are deforested linear corridors (∼3 to 8 m wide) created for oil and gas exploration. Our objectives were to compare the recovery of understory communities on unmounded and mounded seismic lines and determine how recovery varies with microtopographic position. Recovery was evident in the unmounded seismic lines, with higher shrub and total understory cover at the “tops” of the small, natural hummocks than at lower microtopographic positions — much like the trends in adjacent treed fens. In contrast, mounding treatments that artificially created hummocks on seismic lines significantly changed understory communities. Mounded seismic lines had higher forb cover, much lower bryophyte cover, less variation along the microtopographic gradient, and community composition less similar to that of the reference sites than unmounded seismic lines due to higher abundance of marsh-associated species. Our results suggest that mounding narrow seismic lines can be detrimental to the recovery of the understory communities in treed peatlands.

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On tropical mistletoes: tractable models for evolutionary ecology, ecosystem function, and phytochemistry

Botany ◽

10.1139/cjb-2016-0232 ◽

2017 ◽

Vol 95 (3) ◽

pp. 211-217 ◽

Cited By ~ 4

Author(s):

David M. Watson

Keyword(s):

Seed Dispersal ◽

Host Range ◽

Plant Communities ◽

Ecosystem Function ◽

Evolutionary Ecology ◽

Life Sciences ◽

Evolutionary Trajectory ◽

Tropical Regions ◽

Wide Range

In 2001, I synthesised published information on mistletoe–animal interactions, demonstrating the pervasive influence these hemiparasites have on community composition and proposing that mistletoes represent keystone resources. Although the review was global in scope, I noted “Tropical regions, in particular, are underrepresented in the mistletoe literature, and it is unclear if mistletoe is as important in structuring these highly diverse ecosystems as in less diverse temperate areas”. Since then, research on tropical mistletoes has burgeoned, as a growing number of researchers use these forest and woodland hemiparasites to address a wide range of ecological and evolutionary questions. In this commentary, I highlight some recent findings, revisit and refine some emergent inferences, and suggest that tropical mistletoes offer many opportunities for further research, representing tractable models to address many unanswered questions in the life sciences. As well as reinforcing the role of mistletoes as facilitators for plant communities and keystone resources for animal assemblages, research on mistletoe pollination, seed dispersal, and host-range, challenge the established views about the ecological maintenance and evolutionary trajectory of specialization.

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