Vascular plant community dynamics following hexazinone site preparation in the lower Coastal Plain

1993 ◽  
Vol 23 (10) ◽  
pp. 2216-2229 ◽  
Author(s):  
R. Neal Wilkins ◽  
Wayne R. Marion ◽  
Daniel G. Neary ◽  
George W. Tanner
Keyword(s):  
Plant Community ◽  
Community Dynamics ◽  
Vascular Plant ◽  
Species Abundance ◽  
Woody Species ◽  
Application Rate ◽  
Site Preparation ◽  
Herbaceous Vegetation ◽  
Growing Seasons ◽  
Species Abundance Distributions

Differential responses of vascular plant community compositions, diversities, and species-abundance distributions to hexazinone site preparation were evaluated on three 1-year-old clearcuts, each representing a point along a generalized edaphic gradient (xeric sandhill, mesic flatwoods, and hydric hammock). Foliar cover by species was sampled along four 20-m permanent line transects within each of three blocked replications of hexazinone treatments (0.0, 1.7, 3.4, and 6.8 kg/ha) at pretreatment and after the first and second growing seasons post-treatment. Cover by woody species decreased with increasing hexazinone rates on all sites (P < 0.05). Herbaceous vegetation recovered from first-season reductions to levels that did not vary with treatment (xeric sandhill and mesic flatwoods) or increased with increasing hexazinone rates (hydric hammock). Hexazinone tolerance by Gelsemiumsempervirens (L.) Ait.f. and Vaccinium spp. on the xeric sandhill and Ilexglabra (L.) Gray and G. sempervirens on the mesic flatwoods influenced diversity responses by woody and herbaceous vegetation. With increasing rates, herbaceous diversity decreased on the xeric sandhill, did not vary on the mesic flatwoods, and increased on the hydric hammock. Plant community responses to hexazinone were found to be functions of application rate, edaphic factors, adaptive strategies of resident species, and the presence or absence of hexazinone-tolerant species.

Site Preparation Drives Long-Term Plant Community Dynamics in Restored Tallgrass Prairie: A Case Study in Southeastern South Dakota

2016 ◽  
Vol 58 (4) ◽  
pp. 597-605 ◽  
Author(s):  
Alice R. Millikin ◽  
Meghann E. Jarchow ◽  
Karen L. Olmstead ◽  
Rustan E. Krentz ◽  
Mark D. Dixon
Keyword(s):  
South Dakota ◽  
Plant Community ◽  
Tallgrass Prairie ◽  
Community Dynamics ◽  
Site Preparation ◽  
Plant Community Dynamics

scholarly journals Short-Term Plant Community Responses to Warming and Defoliation in a Northern Temperate Grassland

ISRN Ecology ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Eliza S. Deutsch ◽  
Edward W. Bork ◽  
James F. Cahill ◽  
Scott X. Chang
Keyword(s):  
Plant Community ◽  
Community Dynamics ◽  
Plant Biomass ◽  
Temperate Grassland ◽  
Community Diversity ◽  
Native Plant ◽  
Short Term ◽  
Canadian Prairies ◽  
Growing Seasons ◽  
Second Year

Little is known about the short-term impacts of warming on native plant community dynamics in the northern Canadian prairies. This study examined the immediate effects of elevated temperature and defoliation on plant community diversity, composition, and biomass within a native rough fescue (Festuca hallii (Vasey) Piper) grassland over two growing seasons. We used open-top chambers to simulate climate change and defoliated vegetation in midsummer of the first year to simulate biomass loss associated with periodic ungulate grazing. Warming marginally increased plant species diversity and changed community composition shortly after treatment, but effects were not apparent the second year, and there were no apparent impacts on plant biomass. Nonetheless, warming may have impacted community diversity indirectly through reduced soil moisture content, a pattern that persisted into the second year. Overall, this northern temperate grassland demonstrated limited community-level changes to warming even in the presence of defoliation.

scholarly journals Towards a unification of niche and neutral models of community ecology

2018 ◽  
Author(s):  
Andres Laan ◽  
Gonzalo G. de Polavieja
Keyword(s):  
Population Dynamics ◽  
Large Scale ◽  
Community Dynamics ◽  
Neutral Theory ◽  
Species Abundance ◽  
Theory Model ◽  
Niche Theory ◽  
Species Abundance Distributions ◽  
Restoring Forces ◽  
Neutral Models

AbstractEcological models of community dynamics fall into two main categories. The neutral theory of biodiversity correctly predicts various large-scale ecosystem characteristics such as the species abundance distributions. On a smaller scale, the niche theory of species competition explains population dynamics and interactions between two to a dozen species. Despite the successes of the two theories, they rely on two contradictory assumptions. In the neutral theory each species is competitively equivalent while in the niche theory every species is specialized to exploit a specific part of its environment. Here we propose a resolution to this contradiction using a game theory model of competition with an attractor hyperplane as its equilibrium solution. When the population dynamics shifts within the hyperplane, it is selectively neutral. However, any movement perpendicular to the hyperplane is subject to restoring forces similar to what is predicted by the niche theory. We show that this model correctly reproduces empirical species abundance distributions and is also compatible with species removal experiments.

scholarly journals The Dynamic Hypercube as a Niche Community Model

2021 ◽  
Vol 9 ◽  
Author(s):  
John M. Halley ◽  
Stuart L. Pimm
Keyword(s):  
Community Dynamics ◽  
Neutral Theory ◽  
Species Abundance ◽  
Ecological Communities ◽  
Evolutionary Time ◽  
Community Model ◽  
Theory Of Island Biogeography ◽  
Species Abundance Distributions ◽  
Hypercube Model ◽  
Zero Sum

Different models of community dynamics, such as the MacArthur–Wilson theory of island biogeography and Hubbell’s neutral theory, have given us useful insights into the workings of ecological communities. Here, we develop the niche-hypervolume concept of the community into a powerful model of community dynamics. We describe the community’s size through the volume of the hypercube and the dynamics of the populations in it through the fluctuations of the axes of the niche hypercube on different timescales. While the community’s size remains constant, the relative volumes of the niches within it change continuously, thus allowing the populations of different species to rise and fall in a zero-sum fashion. This dynamic hypercube model reproduces several key patterns in communities: lognormal species abundance distributions, 1/f-noise population abundance, multiscale patterns of extinction debt and logarithmic species-time curves. It also provides a powerful framework to explore significant ideas in ecology, such as the drift of ecological communities into evolutionary time.

scholarly journals Plant Community Structure within a Reclamation Field Trial and Forested Reference Sites in a Post-Mine Environment

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 776
Author(s):  
Sean B. Rapai ◽  
Brianna Collis ◽  
Thomas Henry ◽  
Kimberly Lyle ◽  
Steven G. Newmaster ◽  
...  
Keyword(s):  
Plant Community ◽  
Field Trial ◽  
Native Species ◽  
Vascular Plant ◽  
Alpha Diversity ◽  
Woody Species ◽  
Plant Functional Groups ◽  
Reference Sites ◽  
Significant Difference ◽  
Additional Reference

Early successional plant community assemblage within a reclamation field trial at the Detour Lake Mine in northeastern Ontario is assessed, and compared with reference forested and historically reclaimed sites. The reclamation field trial examines eight amendment treatment combinations that include treatments with a winter kill cover crop of oats, fertilizer, biosolids, peat, and combinations thereof. The objectives of this study are to: (1) Investigate how soil amendments influence plant functional group establishment and growth in mine overburden; and (2) Explore the amendment properties that best support the establishment and growth of a plant community that resembles the baseline reference sites. Currently, the presence of non-native species and a dominant woody plant community explains the largest proportion of variance between the forested upland and lowland reference sites and all reclaimed sites. Similar to non-native species, graminoids were absent from the upland forested reference sites. The difference in the graminoid community explains much of the variance between the forested reference sites and all reclaimed sites. The cumulative additions of fertilizer and peat increased alpha diversity of non-native and graminoid plants within the amendment treatments, which had greater alpha diversity of these plant functional groups than the forested reference sites. Within the amendment treatments, non-native and graminoid alpha diversity was initially greater in the nutrient treatments, but by 2019 there was no significant difference in non-native or graminoid alpha diversity between amendment treatments. The results indicate that applications of nutrients through fertilizer or biosolids may increase graminoid alpha diversity and abundance within reclamation units in year 1. The results also confirm that the vascular plant community composition present within the historically reclaimed sites and amendment treatments does not resemble the forested reference sites. The plant community present within the amendment treatment sites is best described as early successional, with the presence of non-native herbaceous legumes dominating the historically reclaimed sites. Despite this, the results indicate that fertilizer and biosolids-based treatments have developed a vascular plant community, excluding woody species that is more similar to the forested reference sites than the peat-based treatments. Further research and long-term monitoring are needed to determine which amendment treatment will best support a plant community that resembles the forested reference sites. In addition, future studies of this nature might consider including wildfire affected and post-harvested forest stands as additional reference sites, to better capture possible plant community trajectories of a severely disturbed environment.

scholarly journals Emergent neutrality in consumer-resource dynamics

2019 ◽  
Author(s):  
Rafael D’Andrea ◽  
Theo Gibbs ◽  
James P. O’Dwyer
Keyword(s):  
Community Dynamics ◽  
Neutral Theory ◽  
Species Abundance ◽  
Natural World ◽  
Biodiversity Patterns ◽  
Interspecific Differences ◽  
Community Turnover ◽  
Species Abundance Distributions ◽  
Resource Dynamics ◽  
Taxonomic Groups

AbstractNeutral theory assumes all species and individuals in a community are ecologically equivalent. This controversial hypothesis has been tested across many taxonomic groups and environmental contexts, and successfully predicts species abundance distributions across multiple high-diversity communities. However, it has been critiqued for its failure to predict a broader range of community properties, particularly regarding community dynamics from generational to geological timescales. Moreover, it is unclear whether neutrality can ever be a true description of a community given the ubiquity of interspecific differences, which presumably lead to ecological inequivalences. Here we derive analytical predictions for when and why non-neutral communities of consumers and resources may present neutral-like outcomes, which we verify using numerical simulations. Our results, which span both static and dynamical community properties, demonstrate the limitations of summarizing distributions to detect non-neutrality, and provide a potential explanation for the successes of neutral theory as a description of macroecological pattern.Author SummaryThe neutral theory of biodiversity assumes that species are ecologically equivalent. Given the natural history observation of ubiquitous phenotypic differences between species, it is surprising that neutral theory has successfully predicted a broad range of biodiversity patterns, and simultaneously unsurprising that these results have not convinced ecologists that the natural world is neutral. However, we have lacked a description of how neutrality can emerge in a natural way from ecological mechanisms and species differences. Our study sheds light on this question, providing a theoretical backdrop for the success of neutral theory as a description of macroecological pattern. We derive a prediction for the degree to which consumers must differ in preferences for different resources before the resulting biodiversity patterns become distinguishable from neutrality. These predictions, which we confirm using simulations, show that neutral-like outcomes are possible even when resource requirements across consumers are very far from neutral. Our results can be tested in experimental microbial communities, where, equipped with an inferred consumption network, our analysis can yield predictions for biodiversity patterns and community turnover at different taxonomic levels.

Plant Community Dynamics, Nutrient Cycling, and Alternative Stable Equilibria in Peatlands

2002 ◽  
Vol 160 (5) ◽  
pp. 553
Author(s):  
Pastor ◽  
Peckham ◽  
Bridgham ◽  
Weltzin ◽  
Chen
Keyword(s):  
Nutrient Cycling ◽  
Plant Community ◽  
Community Dynamics ◽  
Plant Community Dynamics ◽  
Stable Equilibria
Sign in / Sign up

Export Citation Format

Share Document