Download or read book Ecosystem Functioning in Restored Grassland as Influenced by Ecotypic Variation Precipitation and Biodiversity written by Kiersten Bergquist and published by . This book was released on 2020 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: The restoration of degraded tallgrass prairies can mitigate climate change due to the carbon accrued during the development of grasslands. The focal species, dominant grass Andropogon gerardii, can assist the recovery of grassland ecosystem functioning. Climate, local adaptation, and biodiversity have been found to impact the accrual of carbon in grasslands. This study examined the difference in ecosystem functioning between ecotypes along a dry to mesic precipitation scale. The study site for this project was at the Southern Illinois University Agriculture Research Center in Carbondale, Illinois. The field site was planted with seeds originating from dry to mesic ecotypes, and the resulting ecosystem functioning was analyzed. It was found that the Kansas non-local ecotypes had significantly higher biodiversity, while the local Illinois sites demonstrated local adaptation with A. gerardii. Aboveground plant biomass was higher in the local sites, but there was no difference in carbon accrual between any of the ecotypes. While ecotypic variation in a dominant species will usually differentially influence ecosystem functioning, in this case, high biodiversity and local adaptation result in similar carbon inputs in grassland soil. It is necessary to analyze the carbon content of the soil in the drier field sites in order to determine if major differences in rainfall leads to differences in carbon accrual. If the goal of restoring a tallgrass prairie in southern Illinois is to assist with climate change mitigation, then it does not make a significant difference if the dominant species is sourced locally or non-locally.

Download or read book Climate Change Implications for Grassland Ecosystems written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Grassland Ecosystems Functioning and Stability in Response to Climatic Variability and Climate Extremes written by Md Lokman Hossain and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Grasslands have been considered the most imperiled ecosystems in the world because, over the past three decades, grasslands have been subjected to major natural and anthropogenic disturbances (e.g., land-use change and global climate change). Despite there is increasing evidence that grassland ecosystems are under threat of global climate change, our understanding of the functioning (e.g., aboveground biomass (AGB) and below-ground biomass (BGB)) and stability (e.g., resistance and resilience) of these ecosystems in response to climatic variability and climate extremes is limited. In this thesis, grassland biomass observations in 5 ecoregions (cold steppe, humid temperate, humid savanna, savanna and temperate dry steppe) and Bayreuth Biodiversity Experiment were studied to examine the effects of climatic variability and climate extremes on ecosystem functioning and assess the role of biodiversity on ecosystem functioning and stability. Growing-season climatic variables were defined based on respective harvests (hereafter single-harvest), which include growing-season temperature (GST), precipitation (GSP), mean temperature (GSTmean), maximum temperature (GSTmax), minimum temperature (GSTmin) and cumulative precipitation (GSPcum). Annual climatic variables include mean annual temperature (MAT), maximum temperature (MATmax), minimum temperature (MATmin), annual precipitation (AP) and frequency (APfreq). Standardized Precipitation Evapotranspiration Index was used to identify growing-season and annual climatic conditions (extreme dry, moderate dry, normal, moderate wet and extreme wet) based on drought index classification. Annual harvest frequencies were classified into extensive, low-intensive, mid-intensive, and intensive. Biomass (i.e., AGB, BGB and BGB:AGB ratio) data were analyzed using multiple tests (i.e. Pearson correlation, one-way ANOVA, post-hoc test, generalized linear models and linear mixed-effects models. Results showed that irrespective of study sites, ecoregions and plant types, growing-season climatic variables were the strong determinants in controlling single-harvest biomass rather than the annual climatic variables in explaining annual biomass. For example, single-harvest AGB in cold steppe, humid temperate and humid savanna ecoregions increased with increasing GSP and GST. For total BGB in C3- and C4- dominated grasslands across ecoregions, GST, GSTmax and GSTmin had significantly positive effects on the single-harvest BGB of C3 plants in humid temperate and cold steppe, and C4 plants in temperate dry steppe and savanna ecoregions. When BGB:AGB ratio was examined, I found that the single-harvest BGB:AGB ratio of C4-dominated grasslands increased, and C3-dominated grassland decreased with GST and GSTmax. The differential effects of climate extremes on biomass were not only caused by the differences in sites, ecoregions and plant types, but also ascribed by the direction and timescale of climate extremes. Compared to normal climatic conditions, the single-harvest BGB:AGB ratio of C3-dominated grasslands in cold steppe and C4- dominated grasslands in savanna and humid savanna ecoregions was higher (lower) in growing-season dry (wet) climatic conditions. Higher single-harvest BGB:AGB ratio of C4-dominated grasslands in savanna and humid savanna in growing-season extreme dry climatic conditions caused by a decrease (increase) of AGB (BGB) in iii these grasslands. The C3-dominated grasslands in cold steppe ecoregion are at great threat of drought, as it was observed that growing-season extreme dry climates reduced both the single-harvest AGB and BGB. The relationships between species richness and AGB were (i) concave-up in June harvest and unimodal in September harvests for dry conditions, and (ii) negative linear in June harvests and positive linear in September harvests for the wet conditions. Species richness increased ecosystem resistance against climate extremes of different intensities and directions but decreased resilience towards climate extremes of all dry events. This research concludes that growing-season climatic variables rather than annual climatic variables are the strong determinant in predicting grassland biomass productivity. The observed significant effects of climate extremes on biomass in most sites and ecoregions suggest that the functioning and stability of grasslands in these ecoregions are potentially under threat of increasing intensity and frequency of climate extremes. However, in order to buffer the negative effects of climate extremes on ecosystem functioning, the presence of higher species richness and functional groups is of great importance. This research helps improve the understanding of the differences in the responses of grassland functioning to climatic variability and climate extremes across ecoregions and provides new insights into biodiversity-functioning and biodiversity-stability relationships under climate extremes, which is of importance to achieving sustainable grassland management in different geographical regions.

Download or read book Grassland Productivity and Ecosystem Services written by Gilles Lemaire and published by CABI. This book was released on 2011 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Grassland ecosystems are deeply affected by human activities and need appropriate management to optimise trade-offs between ecosystem functions and services. Until now they have mainly been analysed as agro-ecosystems for animal production but this book looks beyond the role of grassland as a feeding ground, and evaluates other important processes such as carbon sequestration in soils, greenhouse gas regulation and biodiversity protection. This authoritative volume expertly highlights the need for an immediate balance between agriculture and ecological management for sustainability in the futu.

Download or read book Grasslands and Climate Change written by David J. Gibson and published by Cambridge University Press. This book was released on 2019-03-21 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive assessment of the effects of climate change on global grasslands and the mitigating role that ecologists can play.

Download or read book The Biology of Grasslands written by Brian Wilsey and published by Oxford University Press. This book was released on 2018-06-22 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: This accessible text provides a concise but comprehensive introduction to the biology of global grasslands. Grasslands are vast in their extent, with native and non-native grasslands now covering approximately 50% of the global terrestrial environment. They are also of vital importance to humans, providing essential ecosystem services and some of the most important areas for the production of food and fibre worldwide. It has been estimated that 60% of calories consumed by humans originate from grasses, and most grain consumed is produced in areas that were formerly grasslands or wetlands. Grasslands are also important because they are used to raise forage for livestock, represent a source of biofuels, sequester vast amounts of carbon, provide urban green-space, and hold vast amounts of biodiversity. Intact grasslands contain an incredibly fascinating set of plants, animals, and microbes that have interested several generations of biologists, generating pivotal studies to important theoretical questions in ecology. As with other titles in the Biology of Habitats Series, the emphasis is on the organisms that dominate this environment although restoration, conservation, and experimental aspects are also considered.

Download or read book Processes that Influence Biodiversity Ecosystem Functioning and Stability in Grasslands written by Forest Isaac Isbell and published by . This book was released on 2010 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guidelines for Native Seed Production and Grassland Restoration written by Kathrin Kiehl and published by Cambridge Scholars Publishing. This book was released on 2014-06-19 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: World-wide, the degradation and destruction of both natural and traditionally used semi-natural ecosystems is drastically increasing. Unfortunately, commercial seed mixtures, consisting of non-native species and genetically uniform cultivars, are widely used in grassland restoration, often with negative effects on biodiversity. Therefore, native species should be used in the ecological restoration of natural and semi-natural vegetation. This book compiles results from recent studies presented at a Special Session “Native seed production and use in restoration projects”, which was organised during the 8th European Conference on Ecological Restoration in České Budějovice, Czech Republic. The authors review the ecological and genetic aspects of seed propagation and species introduction both from a European and an American perspective, and discuss implications for the development of seed zones and for native seed production. Examples from different countries focus on native seed production in practice, and suggest different approaches for the certification of seed provenance. Best practice examples from Europe and the United States are used to indicate the advantages of using native seeds for ecological restoration of grasslands, field margins and sagebrush steppe. Finally, this volume also provides guidelines for the successful implementation of restoration projects for local authorities, landscape planners and NGOs in order to bridge gaps between research and practice.

Download or read book Biogeographic Influences on Grassland Community Structure and Function written by Elisabeth J. Forrestel and published by . This book was released on 2015 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Incorporating evolutionary and biogeographic perspectives into studies of community and ecosystem ecology is of increasing importance, especially in the face of global change. There is a rich history in studying the influence of historical and evolutionary processes on community patterns of diversity (i.e., the connection between regional and local patterns of richness), yet studies that incorporate biogeographic perspectives on the functional properties of communities are limited. Much of this is related to the lack of appropriate datasets to address these questions. But as phylogenetic, biodiversity and functional trait datasets are growing in scale and magnitude, we are beginning to be able to assess the historical and regional influences on the functional properties of communities. These perspectives on community and ecosystem function are necessary to assess whether disparate biogeographic regions will exhibit differential responses to environmental change. Over the course of four chapters, my dissertation explores how regional differences in biogeographic and evolutionary history influence grass community phylogenetic and functional responses to gradients of disturbance and climate. Chapter 1 presents an analysis of the biogeography of grasses and their global distribution based on phylogenetic similarity or shared evolutionary history. We first inferred a Bayesian distribution of completely sampled Poaceae phylogenies, and then utilized expert-determined geographic distributions to generate a set of phylogenetically defined biogeographic regions for grasses. We present patterns of richness, phylogenetic diversity and species-level diversification across these regions, and discuss potential drivers of diversification and resulting richness patterns in grasses. The subsequent chapters compare community level patterns of phylogenetic and functional composition in response to gradients of disturbance and climate in grasslands of North America (NA) and South Africa (SA). These systems are an ideal comparison as they have disparate evolutionary and biogeographic histories, yet span similar climatic space and harbor C4 dominated grasslands. Chapter 2 compares the grass community response to experimentally altered fire regimes in mesic savanna grasslands of NA and SA. Despite differences in their taxonomic response, we found that the grass communities were similar in their phylogenetic and functional responses to high fire frequency, which was driven by the presence of fire-adapted Andropogoneae species at both sites. Chapter 3 compares the response of the experimental removal of grazing by large mammals in mesic savanna grasslands of NA and SA. Despite divergent responses to grazer removal in NA versus SA, functional syndromes associated with grazing resistance were generally conserved across sites, and it was the functional strategies of the dominant species at each site that drove the divergent. responses. Further, our results support the hypothesis that grazing and aridity may be selective forces that act in parallel, as those species that were grazing resistant also occupied drier niches. Our studies demonstrate that savanna grassland communities with different biogeographic and grazing histories respond differently to the removal of large herbivores, and that climate, fire, and grazing are interactive forces in maintaining savanna grassland diversity and function. Chapter 4 compares the total net primary production (ANPP) response of grassland communities to broad precipitation gradients in NA and SA, and the potential functional and phylogenetic drivers that underlie this well-known precipitation-ANPP relationship. We found that annual precipitation explained the vast majority of the variance in production across the gradient and that the relationship was highly similar in both NA and SA. Yet, the traits that underlie these responses were different in each region, which could largely be explained by the turnover of lineages within each region. These results call into question the ability to predict global patterns of ecosystem function utilizing a trait-based approach alone. Overall, my dissertation demonstrates the need to further incorporate phylogenetic and biogeographic perspectives into ecological studies to better explain patterns of both community and ecosystem function.

Download or read book The Effect of Plant Patch Size and Spatial Pattern on Biodiversity Ecosystem Functions and Grassland Community Structure written by Shannon Seahra and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Environmental and Biotic Processes Influencing Floristic Composition Quality Integrity and Function in Tallgrass Prairie Assemblages written by George Charles Manning (IV) and published by . This book was released on 2018 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tallgrass prairie is one of the most threatened grasslands in North America. Conservation of tallgrass prairie focuses on both effective management of remaining native prairie, and restoration of formerly cultivated fields to tallgrass prairie. This research focused on processes and properties relevant to restoration and conservation of tallgrass prairie. Community assembly theory attempts to explain the formation of communities, which can be governed by deterministic or stochastic processes, or some combination of both. Fire and grazing are widely used to manage grasslands for conservation purposes, but few studies have evaluated the effects of these drivers on the conservation value of plant communities measured by the floristic quality index. Pollination services play a vital role in the reproductive stability of the plant community in prairies, though this has not been well studied in restored prairie. The first chapter of this dissertation reports on a sequential restoration approach used to gain insights into the extent to which community assembly is deterministic and stochastic events change the trajectory of community development. The sequential restorations consisted of former agriculture fields restored to prairie, varying only in time since abandonment. Species composition and aboveground net primary production were quantified over time in sequentially restored communities to reveal the predictability of ecological restoration in producing desired communities and ecosystem functions. The sequential restoration plots were established in a block design. The same suite of species was seeded using the same seeding rates in each restoration sequence. Species composition was recorded each September in the year of seeding and each June and September in the two subsequent years for each block. Annual aboveground net primary productivity was collected from 2 randomly placed 0.1 m2 plots per subplot during peak biomass. There was a significant sequence by age interaction for sown, volunteer, and total species composition. Sown, volunteer, and total cover, diversity, and richness also were affected by a sequence by age interaction. Annual net primary production (ANPP) also was affected by a sequence by age interaction for sown and volunteer species. However, total ANPP was only affected by the variable age. Results show that interannual climate variability (specifically growing season precipitation) inhibits a priori determinations of community assembly, which suggests that stochastic processes play a significant role in the community assembly process in tallgrass prairie restoration. Variations in annual precipitation during the installation years likely drove the initial differences in species composition and ANPP. In general this study revealed that drought conditions at the time of restoration may be more deleterious than drought conditions occurring at other times post-establishment. The influence of fire and grazing on soil properties and functions is difficult for land managers and restoration practitioners to assess. Therefore, the objectives for the second study were to (i) to quantify the independent and interactive effects of grazing and fire frequency on floristic quality in native tallgrass prairie, and provide potential benchmarks for community assessment, and (ii) to explore whether floristic quality can serve as an indicator of soil structure and function for more holistic ecosystem assessments. A factorial combination of fire frequencies (1-2, 4, and 20 y return intervals) and grazing (by bison or ungrazed) treatments was sampled for plant species composition and several indicators of soil quality in lowland tallgrass prairie. Floristic quality, diversity, and richness were higher in grazed than ungrazed prairie over all fire frequencies. Available inorganic N, microbial biomass N, total soil N, and soil bulk density were also higher in grazed prairie soil over all fire frequencies. Microbial biomass C, total soil organic C, and total soil N were positively correlated with FQI. This study demonstrated that floristic quality and soil N pools are more strongly influenced by grazing than fire and that floristic quality can be an indicator of total soil C and N stocks in never cultivated lowland prairie. In tallgrass prairie, 85-90 % of angiosperms require an insect or other animal for pollen transfer. Restorations can play a vital role in the reestablishment of pollination services and simultaneously help maintain high levels of diversity in the tallgrass prairie ecosystem. Missed pollination, via temporal asynchronies, could have a number of biological disadvantages for a plant population. In the third study we addressed the effects of missed pollination on floral period, photosynthetic activity, leaf N content, and seed set in a common native tallgrass prairie forb, Penstemon digitalis . In each of 12 plots, 6 individual plants were either bagged to prevent pollination, or left unbagged, to allow for pollination. There was no difference in mean flower duration between netted and open plots. There was a treatment by time interaction for relative chlorophyll concentrations (P = 0.0005). (Abstract shortened by ProQuest.)

Download or read book Response of Regional Sources of Tallgrass Prairie Species to Variation in Climate and Soil Microbial Communities written by Rachel Kathleen Goad and published by . This book was released on 2012 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Restoration of resilient plant communities in response to environmental degradation is a critical task, and a changing climate necessitates the introduction of plant communities adapted to anticipated future conditions. Ecotypes of dominant species can affect associated organisms as well as ecosystem function. The extent of ecotypic variation in dominant tallgrass prairie species and the consequences of this variation for ecosystem functioning were studied by manipulating two potential drivers of plant community dynamics: climate and the soil microbial community. Longer term studies will clarify whether ecotypes of dominant prairie grasses affect ecosystem function or community trajectories differently during restoration. Ecotypes of dominant species may support different soil microflora, potentially resulting in plant-soil feedback. A second experiment tested for local adaptation of prairie plant assemblages to their soil microbial community.

Download or read book The Effects of Interannual Precipitation Variability on the Functioning of Grasslands written by Laureano Gherardi Arbizu and published by . This book was released on 2014 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change will result not only in changes in the mean state of climate but also on changes in variability. However, most studies of the impact of climate change on ecosystems have focused on the effect of changes in the central tendency. The broadest objective of this thesis was to assess the effects of increased interannual precipitation variation on ecosystem functioning in grasslands. In order to address this objective, I used a combination of field experimentation and data synthesis. Precipitation manipulations on the field experiments were carried out using an automated rainfall manipulation system developed as part of this dissertation. Aboveground net primary production responses were monitored during five years. Increased precipitation coefficient of variation decreased primary production regardless of the effect of precipitation amount. Perennial-grass productivity significantly decreased while shrub productivity increased as a result of enhanced precipitation variance. Most interesting is that the effect of precipitation variability increased through time highlighting the existence of temporal lags in ecosystem response. Further, I investigated the effect of precipitation variation on functional diversity on the same experiment and found a positive response of diversity to increased interannual precipitation variance. Functional evenness showed a similar response resulting from large changes in plant-functional type relative abundance including decreased grass and increased shrub cover while functional richness showed non-significant response. Increased functional diversity ameliorated the direct negative effects of precipitation variation on ecosystem ANPP but did not control ecosystem stability where indirect effects through the dominant plant-functional type determined ecosystem stability. Analyses of 80 long-term data sets, where I aggregated annual productivity and precipitation data into five-year temporal windows, showed that precipitation variance had a significant effect on aboveground net primary production that is modulated by mean precipitation. Productivity increased with precipitation variation at sites where mean annual precipitation is less than 339 mm but decreased at sites where precipitation is higher than 339 mm. Mechanisms proposed to explain patterns include: differential ANPP response to precipitation among sites, contrasting legacy effects and soil water distribution. Finally, increased precipitation variance may impact global grasslands affecting plant-functional types in different ways that may lead to state changes, increased erosion and decreased stability that can in turn limit the services provided by these valuable ecosystems.

Download or read book Productivity and sustainability influenced by biodiversity in grassland ecosystems written by David Tilman and published by . This book was released on 1996 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biodiversity Ecosystem Functioning and Human Wellbeing written by Shahid Naeem and published by Oxford University Press. This book was released on 2009-07-30 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book starts by summarizing the development of the basic science and provides a meta-analysis that quantitatively tests several biodiversity and ecosystem functioning hypotheses.

Download or read book Foundations of Restoration Ecology written by Society for Ecological Restoration International and published by Island Press. This book was released on 2016-11 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Society for Ecological Restoration"--Cover.

Download or read book California Grasslands written by Mark R. Stromberg and published by Univ of California Press. This book was released on 2007-12-03 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This highly synthetic and scholarly work brings together new and important scientific contributions by leading experts on a rich diversity of topics concerning the history, ecology, and conservation of California's endangered grasslands. The editors and authors have succeeded admirably in drawing from a great wealth of recent research to produce a widely accessible and compelling, state-of-the-art treatment of this fascinating subject. Anyone interested in Californian biodiversity or grassland ecosystems in general will find this book to be an invaluable resource and a major inspiration for further research, management, and restoration efforts."—Bruce G. Baldwin, W. L. Jepson Professor and Curator, UC Berkeley "Grasses and grasslands are among the most important elements of the California landscape. This is their book, embodying the kind of integrated view needed for all ecological communities in California. Approaches ranging across an incredibly broad spectrum -- paleontology and human history; basic science and practical management techniques; systematics, community ecology, physiology, and genetics; physical factors such as water, soil nutrients, atmospherics, and fire; biological factors such as competition, symbiosis, and grazing -- are nicely tied together due to careful editorial work. This is an indispensable reference for everyone interested in the California environment."—Brent Mishler, Director of the University & Jepson Herbaria and Professor of Integrative Biology, UC Berkeley "The structure and function of California grasslands have intrigued ecologists for decades. The editors of this volume have assembled a comprehensive set of reviews by a group of outstanding authors on the natural history, structure, management, and restoration of this economically and ecologically important ecosystem."—Scott L. Collins, Professor of Biology, University of New Mexico