Academic literature on the topic 'Grasslands ecosystems; Grazing'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Grasslands ecosystems; Grazing.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Grasslands ecosystems; Grazing"
1
Breitkreuz, Sarah, Laio Silva Sobrinho, Leah Stachniak, and Scott Chang. "Can the Adaptive Multi-Paddock Grazing System Increase Carbon Sequestration in Alberta's Grassland Soils?" Alberta Academic Review 2, no. 2 (September 11, 2019): 13–14. http://dx.doi.org/10.29173/aar52.
Full textAbstract:
Natural grasslands cover around 40% of the Earth’s surface and play an important role as a source of ecological goods and services. By sequestering around 30% of terrestrial global carbon, grasslands play a critical part in the alleviation of climate change. Despite their ecological significance, grasslands have been reduced to a fraction of their original extent. In Canada, up to 70% of grasslands have been destroyed, making it the most endangered ecosystem in North America. What remains is often intensely grazed and a diverse ecosystem of wild animals is replaced by domestic livestock. The continuous application of poor grazing management by ranchers is one of the main causes for the depletion of natural grasslands, resulting in the release of stored soil carbon back into the atmosphere. Fortunately, 60-70% of the depleted carbon can be re-sequestered through the adoption of improved grazing management, thus improving grassland ecosystems. The Adaptive Multi-Paddock (AMP) grazing system is an example of improved grazing management. AMP grazing is a system in which livestock is frequently rotated between multiple fenced paddocks. Compared to conventional grazing practices (Non-AMP), the AMP system is a favorable solution which can improve carbon sequestration in world wide grasslands soils– and in turn, contribute to the mitigation of climate change. By regenerating grassland ecosystems, AMP grazing could potentially aid in creating a more sustainable, resilient agroecosystem. Our goal is to study the effect of AMP grazing on soil organic carbon (SOC) sequestration in Canadian grasslands. First, we collected soil cores from 30 study sites located throughout the grassland ecoregions in Canada. Each site consisted of a pair of ranches: one AMP and one Non-AMP. Second, we analyzed the soil cores for total carbon using an elemental analyzer. There does not seem to be any substantial difference in total carbon between AMP and Non-AMP systems, however we have yet to differentiate between soil organic carbon and soil inorganic carbon. Once we distinguish the two variables we will be able to confirm the effectiveness of the AMP grazing system in increasing carbon sequestration in Canadian grasslands.
Literature Cited:
Derner, J. D., & Schuman, G. E. (2007). Carbon sequestration and rangelands: a synthesis of land management and precipitation effects. Journal of soil and water conservation, 62(2), 77-85.
Gauthier, D. A., & Wiken, E. B. (2003). Monitoring the conservation of grassland habitats, Prairie Ecozone, Canada. Environmental Monitoring and Assessment, 88(1-3), 343-364.
Samson, F., & Knopf, F. (1994). Roundtable: prairie conservation in North America. BioScience, 44(6), 418-421
Kraus, D. (2016). Why Canada’s Prairies are the World’s Most Endangered Ecosystem. Retrieved from: http://www.natureconservancy.ca/en/blog/archive/grasslands-the-most.html#.XUnsE-hKi70
Lal, R. (2002). Soil carbon dynamics in cropland and rangeland. Environmental pollution, 116(3), 353-362
Teague, W. R. (2018). Forages and pastures symposium: Cover crops in livestock production: Whole-system approach: Managing grazing to restore soil health and farm livelihoods. Journal of animal science, 96(4), 1519-1530.
2
Chang, J. F., N. Viovy, N. Vuichard, P. Ciais, T. Wang, A. Cozic, R. Lardy, et al. "Incorporating grassland management in ORCHIDEE: model description and evaluation at 11 eddy-covariance sites in Europe." Geoscientific Model Development 6, no. 6 (December 20, 2013): 2165–81. http://dx.doi.org/10.5194/gmd-6-2165-2013.
Full textAbstract:
Abstract. This study describes how management of grasslands is included in the Organizing Carbon and Hydrology in Dynamic Ecosystems (ORCHIDEE) process-based ecosystem model designed for large-scale applications, and how management affects modeled grassland–atmosphere CO2 fluxes. The new model, ORCHIDEE-GM (grassland management) is enabled with a management module inspired from a grassland model (PaSim, version 5.0), with two grassland management practices being considered, cutting and grazing. The evaluation of the results from ORCHIDEE compared with those of ORCHIDEE-GM at 11 European sites, equipped with eddy covariance and biometric measurements, shows that ORCHIDEE-GM can realistically capture the cut-induced seasonal variation in biometric variables (LAI: leaf area index; AGB: aboveground biomass) and in CO2 fluxes (GPP: gross primary productivity; TER: total ecosystem respiration; and NEE: net ecosystem exchange). However, improvements at grazing sites are only marginal in ORCHIDEE-GM due to the difficulty in accounting for continuous grazing disturbance and its induced complex animal–vegetation interactions. Both NEE and GPP on monthly to annual timescales can be better simulated in ORCHIDEE-GM than in ORCHIDEE without management. For annual CO2 fluxes, the NEE bias and RMSE (root mean square error) in ORCHIDEE-GM are reduced by 53% and 20%, respectively, compared to ORCHIDEE. ORCHIDEE-GM is capable of modeling the net carbon balance (NBP) of managed temperate grasslands (37 ± 30 gC m−2 yr−1 (P < 0.01) over the 11 sites) because the management module contains provisions to simulate the carbon fluxes of forage yield, herbage consumption, animal respiration and methane emissions.
3
Bi, Xu, Bo Li, Xiangchao Xu, and Lixin Zhang. "Response of Vegetation and Soil Characteristics to Grazing Disturbance in Mountain Meadows and Temperate Typical Steppe in the Arid Regions of Central Asian, Xinjiang." International Journal of Environmental Research and Public Health 17, no. 12 (June 25, 2020): 4572. http://dx.doi.org/10.3390/ijerph17124572.
Full textAbstract:
Grazing is one of the most common causes of grassland degradation, therefore, an assessment of soil physicochemical properties and plant nutrients under grazing is important for understanding its influences on ecosystem nutrient cycling and for formulating appropriate management strategies. However, the effects of grazing on grassland soil physicochemical properties and plant nutrients in mountain meadow and temperate typical steppe in the arid regions are still unclear. Therefore, we investigated the vegetation nutrient concentrations of nitrogen, phosphorus and potassium (N, P, and K) as well as soil physicochemical properties in the topmost 40 cm depth soil, to evaluate how these factors respond to grazing disturbance in a mountain meadow and temperate typical steppe within a mountain basin system in arid regions. Our results revealed that the soil bulk density values at depth of 0–40 cm increased after grazing in the mountain meadow and temperate typical steppe, whereas the soil water content decreased in the mountain meadow and increased in the temperate typical steppe after grazing. In the mountain meadow, soil total N and available P in addition to vegetation N and P concentrations increased in response to high-intensity grazing, while soil available N, available K and vegetation K decreased after grazing; in addition, soil pH, soil total P and K showed no significant changes. In the temperate typical steppe, the soil total P, soil available N, P, and K, and vegetation N, P, and K increased under relatively low-intensity grazing, whereas soil pH and soil total K showed no significant changes except for the deceasing soil total N. Our findings showed the different responses of different grassland ecosystems to grazing. Moreover, we propose that further related studies are necessary to better understand the effects of grazing on grassland ecosystems, and thereby provide a theoretical basis for the sustainable use of animal husbandry and ecological restoration of grasslands.
4
Gong, Y. M., A. Mohammat, X. J. Liu, K. H. Li, P. Christie, F. Fang, W. Song, et al. "Response of carbon dioxide emissions to sheep grazing and N application in an alpine grassland – Part 2: Effect of N application." Biogeosciences 11, no. 7 (April 3, 2014): 1751–57. http://dx.doi.org/10.5194/bg-11-1751-2014.
Full textAbstract:
Abstract. Widespread nitrogen (N) enrichment resulting from anthropogenic activities has led to great changes in carbon exchange between the terrestrial biosphere and the atmosphere. Grassland is one of the most sensitive ecosystems to N deposition. However, the effect of N deposition on ecosystem respiration (Re) in grasslands has been conducted mainly in temperate grasslands, which are limited largely by water availability, with few studies focused on alpine grasslands that are primarily constrained by low temperatures. Failure to assess the magnitude of the response in Re outside the growing season (NGS) in previous studies also limits our understanding of carbon exchange under N deposition conditions. To address these knowledge gaps we used a combination of static closed chambers and gas chromatography in an alpine grassland from 2010 to 2011 to test the effects of N application on ecosystem respiration (Re) both inside and outside the growing season. There was no significant change in CO2 emissions under N application. Re outside the growing season was at least equivalent to 9.4% of the CO2 fluxes during the growing season (GS). Annual Re was calculated to be 279.0–403.9 g CO2 m−2 yr−1 in Bayinbuluk alpine grasslands. In addition, our results indicate that soil temperature was the dominant abiotic factor regulating variation in Re in the cold and arid environment. Our results suggest that short-term N additions exert no significant effect on CO2 emissions in alpine grassland.
5
Huang, Xiaotao, Li Ma, Geping Luo, Chunbo Chen, Gangyong Li, Yang Yan, Huakun Zhou, Buqing Yao, and Zhen Ma. "Human appropriation of net primary production estimates in the Xinjiang grasslands." PLOS ONE 15, no. 12 (December 2, 2020): e0242478. http://dx.doi.org/10.1371/journal.pone.0242478.
Full textAbstract:
The human appropriation of net primary production (HANPP) was developed to estimate the intensity of human activities in natural ecosystems, which is still unclear in the Xinjiang grasslands. Using the Biome-Biogeochemical Cycle (Biome-BGC) grazing model in combination with field data, we assessed the HANPP and explored its spatiotemporal patterns in the Xinjiang grasslands. Our results showed that (1) the HANPP increased from 38 g C/m2/yr in 1979 to 88 g C/m2/yr in 2012, with an average annual increase of 1.47%. The HANPP was 80 g C/m2/yr, which represented 51% of the potential net primary production (NPPpot), and the HANPP efficiency was 70% in this region. (2) The areas with high HANPP values mainly occurred in northern Xinjiang and northwest of the Tianshan Mountains, while areas with low HANPP values mainly occurred in southern Xinjiang and southwest of the Tianshan Mountains. (3) Interannual variations in HANPP and NPPpot were significantly positively correlated (P<0.01). Interannual variations in HANPP efficiency and grazing intensity were negatively correlated (P<0.01). These results can help identify the complex impacts of human activities on grassland ecosystems and provide basic data for grassland management.
6
Gong, Y. M., A. Mohammat, X. J. Liu, K. H. Li, P. Christie, F. Fang, W. Song, et al. "Response of carbon dioxide emissions to sheep grazing and N application in an alpine grassland – Part 1: Effect of sheep grazing." Biogeosciences 11, no. 7 (April 3, 2014): 1743–50. http://dx.doi.org/10.5194/bg-11-1743-2014.
Full textAbstract:
Abstract. Previous work has failed to address fully the response of (autotrophic and heterotrophic) respiration to grazing in different ecosystems, particularly in alpine grasslands outside the growing season. From 2010 to 2011 a field experiment combined two methods (static closed chambers and a closed dynamic soil CO2 flux system) in alpine grasslands located in the Tianshan Mountains. We examined the effects of grazing regime on ecosystem respiration (Re) both outside (NGS) and during (GS) the growing season and determined the pattern of Re in relation to climate change. There was no significant change in CO2 emissions under grazing. Heterotrophic respiration (Rh) accounted for 78.5% of Re with short-term grazing exclusion and 93.2% of Re with long-term grazing exclusion. Re, Rh and autotrophic respiration (Ra) fluxes outside the growing season were equivalent to 12.9%, 14.1% and 11.4% of the respective CO2 fluxes during the growing season. In addition, our results indicate that soil water content played a critical role in Ra in the cold and arid environment. Both Rh and Re were sensitive to soil temperature. Moreover, our results suggest that grazing exerted no significant effect on CO2 emissions in these alpine grasslands.
7
Zhai, Xiajie, Tingting Lu, Shiming Tang, Xiaojuan Liu, Xiuzhi Ma, Guodong Han, Andreas Wilkes, and Chengjie Wang. "Methane Emission from Sheep Respiration and Sheepfolds During the Grazing Season in a Desert Grassland." Open Atmospheric Science Journal 9, no. 1 (December 22, 2015): 23–28. http://dx.doi.org/10.2174/1874282301509010023.
Full textAbstract:
Methane (CH4) emissions from ruminants should be accounted for the natural grazed rangeland ecosystems when devising greenhouse gas budget inventory, in particular, their contribution to global warming. In this study, CH4 emission from sheep respiration at different grazing intensities (light grazing, 0.75 sheep/ha, LG; moderate grazing, 1.50 sheep/ha, MG; and heavy grazing, 2.25 sheep/ha, HG) and in sheepfolds were evaluated in a desert grassland of Inner Mongolia. Results indicated that daily CH4 emission from sheep was not significantly different between treatments. When CH4 emission was expressed emission per 100g daily, there was a significant difference of LG vs HG and MG vs HG, with the values of 15.64g, 20.00g and 28.63g for LG, MG and HG, respectively, during the grazing season. There was no significant difference among CH4 fluxes in sheepfolds (mean 39.0 ug m-1 h-1). Considering CH4 emissions from the grazing ecosystem, net CH4 emissions from LG, MG and HG plots were -18.33, -1.91 and 21.19 g/ha/day, respectively. The digestibility of forage had a positive correlation with CH emission expressed on daily and metabolic body weight basis. It is concluded that MG will improve the balance between CH emission from grassland and grazing livestock in the desert grasslands of Inner Mongolia.
8
Soubry, Irini, Thuy Doan, Thuan Chu, and Xulin Guo. "A Systematic Review on the Integration of Remote Sensing and GIS to Forest and Grassland Ecosystem Health Attributes, Indicators, and Measures." Remote Sensing 13, no. 16 (August 18, 2021): 3262. http://dx.doi.org/10.3390/rs13163262.
Full textAbstract:
It is important to protect forest and grassland ecosystems because they are ecologically rich and provide numerous ecosystem services. Upscaling monitoring from local to global scale is imperative in reaching this goal. The SDG Agenda does not include indicators that directly quantify ecosystem health. Remote sensing and Geographic Information Systems (GIS) can bridge the gap for large-scale ecosystem health assessment. We systematically reviewed field-based and remote-based measures of ecosystem health for forests and grasslands, identified the most important ones and provided an overview on remote sensing and GIS-based measures. We included 163 English language studies within terrestrial non-tropical biomes and used a pre-defined classification system to extract ecological stressors and attributes, collected corresponding indicators, measures, and proxy values. We found that the main ecological attributes of each ecosystem contribute differently in the literature, and that almost half of the examined studies used remote sensing to estimate indicators. The major stressor for forests was “climate change”, followed by “insect infestation”; for grasslands it was “grazing”, followed by “climate change”. “Biotic interactions, composition, and structure” was the most important ecological attribute for both ecosystems. “Fire disturbance” was the second most important for forests, while for grasslands it was “soil chemistry and structure”. Less than a fifth of studies used vegetation indices; NDVI was the most common. There are monitoring inconsistencies from the broad range of indicators and measures. Therefore, we recommend a standardized field, GIS, and remote sensing-based approach to monitor ecosystem health and integrity and facilitate land managers and policy-makers.
9
Gong, Y. M., A. Mohammat, X. J. Liu, K. H. Li, P. Christie, F. Fang, W. Song, et al. "Response of carbon dioxide emissions to sheep grazing and nitrogen application in an alpine grassland." Biogeosciences Discussions 10, no. 7 (July 22, 2013): 12285–311. http://dx.doi.org/10.5194/bgd-10-12285-2013.
Full textAbstract:
Abstract. Previous work has failed to address fully the response of (autotrophic and heterotrophic) respiration to grazing and nitrogen (N) addition in different ecosystems, particularly in alpine grasslands outside the growing season. From 2010 to 2011, we combined two methods (static closed chambers and a closed dynamic soil CO2 flux system) in a controlled field experiment in an alpine grassland in the Tianshan Mountains. We examined the effects of grazing and N application on ecosystem respiration (Re) both outside (NGS) and during (GS) the growing season and determined the pattern of Re in relation to climate change. There was no significant change in CO2 emissions under grazing or N application. Heterotrophic respiration (Rh) accounted for 78.5% of Re. Re, Rh and autotrophic respiration (Ra) outside the growing season were equivalent to 12.9, 14.1 and 11.4% of the respective CO2 fluxes during the growing season. In addition, our results indicate that precipitation (soil water content) plays a critical role in Ra in this cold and arid environment. Both Rh and Re were sensitive to soil temperature. Moreover, our results suggest that grazing and N addition exert no significant effect on CO2 emissions in alpine grassland but may alter soil carbon stocks in alpine grassland.
10
Yan, Dongqing, Jing Ren, Jiamei Liu, Yu Ding, and Jianming Niu. "De novo assembly, annotation, marker discovery, and genetic diversity of the Stipa breviflora Griseb. (Poaceae) response to grazing." PLOS ONE 15, no. 12 (December 22, 2020): e0244222. http://dx.doi.org/10.1371/journal.pone.0244222.
Full textAbstract:
Grassland is one of the most widely-distributed ecosystems on Earth and provides a variety of ecosystem services. Grasslands, however, currently suffer from severe degradation induced by human activities, overgrazing pressure and climate change. In the present study, we explored the transcriptome response of Stipa breviflora, a dominant species in the desert steppe, to grazing through transcriptome sequencing, the development of simple sequence repeat (SSR) markers, and analysis of genetic diversity. De novo assembly produced 111,018 unigenes, of which 88,164 (79.41%) unigenes were annotated. A total of 686 unigenes showed significantly different expression under grazing, including 304 and 382 that were upregulated and downregulated, respectively. These differentially expressed genes (DEGs) were significantly enriched in the “alpha-linolenic acid metabolism” and “plant-pathogen interaction” pathways. Based on transcriptome sequencing data, we developed eight SSR molecular markers and investigated the genetic diversity of S. breviflora in grazed and ungrazed sites. We found that a relatively high level of S. breviflora genetic diversity occurred under grazing. The findings of genes that improve resistance to grazing are helpful for the restoration, conservation, and management of desert steppe.
Dissertations / Theses on the topic "Grasslands ecosystems; Grazing"
1
Edwards, Grant R. "The creation and maintenance of spatial heterogeneity in plant communities : the role of plant-animal interactions." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239335.
Full text
2
Oliveira, Tamara Esteves de. "Dinâmica da produção de alimentos no bioma pampa." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/163288.
Full textAbstract:
Esse estudo analisou a dinâmica da produção de alimentos no estado do Rio Grande do Sul e suas consequências para as alterações nas áreas de pastagens naturais no Bioma Pampa. Para tanto, foram analisadas as mudanças no uso da terra nos municípios conforme os Censos Agropecuários de 1975, 1985, 1995/1996 e 2006 e da produção de alimentos de acordo com os relatórios de produção agrícola e pecuária municipais do Instituto Brasileiro de Geografia e Estatística (IBGE). Para analisar as variações na área das culturas e quantidade produzida foi calculado um índice de crescimento relativo. Os municípios foram ordenados conforme a área das categorias em seu território e sua localização por Escalonamento Multidimensional Não Métrico (NMDS). A influência do bioma sobre o uso da terra foi analisada por ENVIFIT e a diferença entre as categorias por PERMANOVA, no software R. No Bioma Pampa ocorreu um decréscimo de 26% nas pastagens naturais desde 1975, apresentando decréscimo de até 12.5%, entre 1975 e 1985. Destacam-se as taxas das lavouras e matas artificiais, em que para lavouras temporárias, apresentaram um crescimento considerável de 1985 para 2005. A influência do Bioma Pampa na composição das categorias de uso da terra manteve-se entre 14 e 15%, havendo diferença entre municípios localizados no Bioma Pampa em todos os anos analisados. Ao longo do tempo foi possível observar uma movimentação significativa das lavouras temporárias e das matas artificiais que principalmente entre 1995 e 2005 começam a integrar a paisagem do bioma. Para enfrentar o desafio de manter atividades agroecológicas em biomas ameaçados o Brasil deve investir em fiscalização, desenvolvendo sistemas de monitoramento capazes de detectar sutis alterações no uso da terra. Por outro lado, a produção de alimentos nesse estado apresentou crescimento na quantidade produzida. Foi observado um crescimento elevado na quantidade produzida de soja, sendo distribuição homogênea em todo o estado. O arroz apresentou redução na quantidade produzida no norte do estado e uma concentração expressiva nas regiões sul e fronteira oeste do estado. Os bovinos mantiveram seu rebanho estável com grande concentração na fronteira oeste. A silvicultura apresentou crescimento em praticamente todo estado, estando sua produção centrada na região sudeste do estado. As lavouras analisadas contribuíram para o PIB do estado e são capazes, hoje e no futuro, de suprir as demandas calóricas do Rio Grande do Sul em caso de necessidades, caso sejam mantidas as características atuais do agronegócio gaúcho. Dessas culturas, a soja foi a que mais disponibilizou calorias e retorno financeiro ao estado, sendo capaz de suprir a demanda local e oferecer excedentes para a exportação. Em todas as culturas, com exceção do milho, o aumento da quantidade de calorias disponibilizadas esteve relacionado ao aumento da área plantada, demandando maiores investimentos e incentivos ao incremento do rendimento das culturas.This study analyzed the food production dynamics in the state of Rio Grande do Sul and its consequences for the changes in the natural grassland areas in the Pampa Biome. To this end, data for land use in the municipalities of Pampa Biome were collected from the Agricultural Censuses of 1975, 1985, 1995/1996 and 2006 as well as the food production data presented at the municipal agricultural and livestock reports published by the Brazilian Institute of Geography and Statistics (IBGE). To analyze the dynamics of the natural grasslands area of natural pastures, the micro-regions were compared every 10 years, the relative growth rate. The comparison between the municipalities was made by the adjusted mean the area allocated for the categories of land use. All municipalities were ranked as the area of the categories in its territory and its location by Multidimensional Scaling Not Metric (NMDS). The influence of the biome on land use was analyzed by ENVIFIT and the difference between the categories by PERMANOVA in Pampa Biome R. In software, there was a 26% decrease in natural pastures since 1975, presenting decrease of up to 12.5% between 1975 and 1985. Noteworthy are the rates of crops and artificial forest in which to temporary crops showed considerable growth from 1985 to 2005. The influence of the Pampa biome in the composition of land use categories remained between 14 and 15%, with significant differences between municipalities in the Pampa biome in all the years analyzed. Over time, it observed a significant movement of temporary crops and artificial forests that mainly between 1995 and 2005 begin to integrate the biome landscape. To face the challenge of maintaining agro-ecological activities threatened biomes in Brazil should invest in surveillance, developing monitoring systems capable of detecting subtle changes in land use. Moreover, the production of food in this state showed an increase in the amount produced. High growth for soy produced, being homogeneously distributed across the state was observed. Rice declined on the amount produced in the northern state and a significant concentration in the south and west of the state border. Cattle kept its stable herd with great concentration on the western border. Forestry grew in almost every state, with its production centered in the southeastern region of the state. The crops analyzed contributed to the state's GDP and are able, today and in the future, to meet the caloric demands of Rio Grande do Sul in the event purposes, if the current features of the gaucho agribusiness are maintained. These crops, soybean was the one that provided calories and financial return to the state, being able to meet local demand and provide surplus for exports. In all crops, except corn, increasing the amount of calories available was related to the increased planted area, requiring greater investments and incentives to increase crop yields.
3
Silva, Vasco Manuel Almeida da. "Assessing the relationship between habitats conservation status and ecosystem services in Natura 2000." Doctoral thesis, ISA, 2020. http://hdl.handle.net/10400.5/21197.
Full textAbstract:
Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia. Universidade de LisboaNatura 2000 is the pan-European network of protected areas and classifies different habitat types, including shrub-grasslands as of conservation interest. The use and management to which these habitat types are subject potentially affect their conservation status and the ecosystem services they generated, including regulating services as carbon storage or wildfire prevention. Wildfire prevention is an important ecosystem service in the Mediterranean region and management practices such as grazing or prescribed burning have been applied in several shrub-grassland areas in Natura 2000. These practices are known to reduce fuel vegetation, but little is known about their effects on the conservation status of these habitats. The main goal of this thesis was to investigate if there are potential trade-offs between fire hazard reduction and conservation in different shrub-grassland habitat types. For this, we assessed changes on plant species composition, vegetation structure, aboveground biomass and potential fire behaviour in plots treated with grazing or prescribed burning in two Natura 2000 sites located in central-west Portugal. Moderate grazing has effectively contributed to the conservation of some shrub-grassland habitat types through reduction of wildfire hazard and maintenance of favourable conservation status. In contrast, higher grazing and browsing pressure negatively affected the conservation status by altering plant species composition and structure of the analysed habitat. Likewise prescribed burning reduced fuel loads and minimized short-term fire hazard, but negatively affected the conservation status of the habitat types considered. Results showed that there are potential management conflicts between fire prevention and conservation in Natura 2000 and that these trade-offs must be considered during fuel management decisions
N/A
4
Laliberté, Etienne. "Land-Use Intensification in Grazing Systems: Plant Trait Responses and Feedbacks to Ecosystem Functioning and Resilience." Thesis, University of Canterbury. School of Forestry, 2011. http://hdl.handle.net/10092/5109.
Full textAbstract:
Land-use change is the single most important global driver of changes in biodiversity. Such changes in biodiversity, in turn, are expected to influence the functioning of ecosystems and their resilience to environmental perturbations and disturbances. It is widely recognised that the use of functional traits and functional diversity is best for understanding the causes and functional consequences of changes in biodiversity, but conceptual development has outpaced empirical applications. This thesis explores these ideas in grazing systems, which are expected to undergo rapid intensification of fertiliser use and grazing pressure to meet the growing global demand for livestock products.
First, a flexible framework for measuring different facets of functional diversity is described, and a new multidimensional functional diversity index, called functional dispersion (FDis), is presented. Second, two vegetation sampling methods are compared with regard to their ability to detect changes in vegetation composition. Third, shifts in plant trait distributions following land-use changes are quantified and compared to null models, and a maximum entropy approach is used to quantify the direction and strength of selection on each trait. Fourth, it is shown that these shifts in trait distributions have cascading effects on primary production, litter decomposition, soil respiration, and ultimately soil carbon sequestration. Finally, data from 18 land-use intensity gradients are used to show that land-use intensification reduces functional redundancy and response diversity, two components of biodiversity that are thought to influence ecosystem resilience to future disturbances.
This study illustrates (i) the importance of considering species functional differences to understand how plant communities react to changes in soil resource availability and grazing pressure, and (ii) how such changes directly, indirectly, and interactively control ecosystem functioning, as well as (iii) increasing the vulnerability of ecosystems to future disturbances.
5
Joner, Fernando. "Redundância funcional em comunidades campestres." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/15810.
Full textAbstract:
Os campos do Rio Grande do Sul apresentam grande biodiversidade, beleza cênica e um importante recurso para a economia do estado, cuja principal atividade é a pecuária. O manejo inadequado do campo traz conseqüências graves para a diversidade e sustentabilidade desse ecossistema através da perda de espécies promovida pelo pastejo excessivo. Entretanto, algumas espécies desempenham as mesmas funções nos ecossistemas, logo a perda de algumas espécies pode não afetar o seu funcionamento, pela compensação de outras espécies do mesmo grupo funcional. Esta redundância funcional aumentaria a confiabilidade do funcionamento do ecossistema quando perturbado, funcionando como um tipo de "seguro" contra a perda de espécies. A hipótese da redundância funcional foi avaliada em ecossistemas campestres através de um experimento de remoção no qual os tratamentos avaliados consistiram em: 1) remoção de duas espécies graminóides, 2) remoção de duas espécies herbáceas não-graminóides, 3) remoção de uma espécie de graminóide e uma herbácea não-graminóide e 4) sem remoção. As evidências indicam que existe redundância funcional para as espécies de plantas em ecossistemas campestres, pois a remoção de uma espécie de cada grupo funcional causou menos modificações na composição de espécies das comunidades que a remoção de duas espécies do mesmo grupo funcional. Observou-se também que a porcentagem da cobertura das espécies remanescentes tende a compensar a remoção de espécies do mesmo grupo funcional. Entretanto, os tratamentos não tiveram efeito para a biomassa aérea. A avaliação de um banco de dados de um experimento de pastejo realizado anteriormente revelou que a redundância funcional está positivamente relacionada com a resistência da comunidade ao pastejo, enquanto a riqueza de espécies não apresentou relação. Áreas de campo com maiores níveis de redundância funcional são mais resistentes ao pastejo, sofrendo menos modificações na composição de espécies de suas comunidades. Além disso, um manejo adequado não reduz os níveis de redundância funcional dos campos. Áreas de campo dentro de unidades de conservação deveriam ser manejas adequadamente mantendo os níveis de redundância funcional e a estabilidade deste ecossistema. Entretanto, novos estudos são necessários para avaliar a importância da redundância funcional em experimentos de longa duração.Grasslands from Rio Grande do Sul present great biodiversity, scenic beauty and an important resource to the province economy, which main activity is cattle grazing. Inadequate pasture management brings serious consequences to ecosystem diversity and sustainability by the loss of species promoted by excessive grazing. Although, some species may role the same functions in ecosystems, therefore loss of some species may not affect functioning, due to species compensation within functional groups. This functional redundancy would increase ecosystem reliability when perturbations occur, working as an "insurance" to species loss. Functional redundancy hypothesis was evidenced in grassland plant communities through a removal experiment in which evaluated treatments were: 1) removal of two graminoid species, 2) removal of two forb species, 3) removal of one species of each functional group and 4) no removal (control). Evidences point to functional redundancy for grassland plant species; removal of one species of each functional group caused less harm to community species composition than removal of two species of the same functional group. Furthermore, remaining species percent covers tend to compensate removed species of the same functional group. However, treatments did not effected aboveground biomass. Data set evaluation of a previously conducted cattle-grazing experiment reveled that functional redundancy is positively related to community resistance to cattle grazing, otherwise species richness presented no relation. Grassland areas with higher levels of functional redundancy are more resistant to cattle grazing, suffering less modification in community species composition. Also, adequate management do not reduce functional redundancy on pastures. Grassland areas inside conservation units should be managed adequately maintaining redundancy levels and ecosystem reliability. Although, new studies are required to better evaluate functional redundancy implications in long term experiments.
6
Wlasichuk, Cynthia. "The impacts of cattle grazing on stream ecosystems in Grasslands National Park of Canada, Saskatchewan." 2014. http://hdl.handle.net/1993/23873.
Full textAbstract:
Cattle are responsible for the deterioration of aquatic and riparian ecosystems throughout the North American prairies. Marked preference for riparian areas has resulted in vegetation loss, stream bank destabilization, changes in sediment particle size, and increased nutrient loads in the streams. A grazing experiment in Grasslands National Park of Canada manipulated the density of cattle to represent a range of grazing intensities (from no grazing to very heavy grazing, 70% forage utilization). This experiment provided the opportunity to study how streams in the semi-arid mixed-grass prairie environment respond to a range of grazing pressure. Nine experimental pastures located on previously ungrazed land within the park boundary and four located within the adjacent community pastures were created, each subjected to a specified grazing treatment. Sampling occurred in the autumn from 2007 to 2009 and included the measurement of 33 physical, chemical, and biological habitat metrics and the characterization of the aquatic invertebrate community. Linear regressions were performed to determine if the habitat variables had a significant relationship to grazing intensity (P < 0.05). Of the habitat variables, two sediment particle size categories were significantly related to grazing intensity: per cent of fine gravel (4-8 mm diameter) (P =0.003) and per cent of medium gravel (8-16 mm diameter) (P = 0.007). The only other habitat variable with a significant linear relationship to grazing intensity was the concentration of suspended carbon in the stream water (P = 0.050). Three invertebrate community metrics were focused on for their expected response to changes associated with cattle impacts:
iii
per cent Chironomidae (%Chiron), per cent Ephemeroptera, Odonata, and Trichoptera (%EOT), and taxa richness. There was a significant non-linear relationship between %Chiron (P = 0.005) and grazing intensity, no linear or non-linear relationship between %EOT and grazing intensity, and a non-linear trend between richness and grazing intensity (P = 0.083). A Reference Condition Approach was used to test for the effects of grazing on the invertebrate community. Multiple regression was used to create a model predicting the invertebrate community from habitat metrics. Of the three community metrics, only richness resulted in a model with acceptable predictive ability. The predicted richness values for each test site were calculated and their residuals were determined and compared to the distribution of residuals observed in the reference sites. Using this technique, I determined that 73.3% of the sites subjected to grazing deviated significantly for the reference condition and were therefore deemed to be impacted. There was no significant relationship between the test site residuals and grazing intensity. The macroinvertebrate community in this semi-arid environment is already under a lot of stress, the addition of cattle to the environment, even at low intensities, pushed the community beyond the reference condition.
Books on the topic "Grasslands ecosystems; Grazing"
1
Manske, Llewellyn L. Restoration of degraded prairie ecosystems. Dickinson, N.D: North Dakota State University, Dickinson Research Extension Center, 2007.
Find full text
2
Manske, Llewellyn L. Restoration of degraded prairie ecosystems. Dickinson, N.D: North Dakota State University, Dickinson Research Extension Center, 2007.
Find full text
3
Manske, Llewellyn L. Restoration of degraded prairie ecosystems. Dickinson, N.D: North Dakota State University, Dickinson Research Extension Center, 2007.
Find full textBook chapters on the topic "Grasslands ecosystems; Grazing"
1
Hirobe, Muneto, and Junji Kondo. "Effects of Climate and Grazing on Surface Soil in Grassland." In The Mongolian Ecosystem Network, 105–14. Tokyo: Springer Japan, 2012. http://dx.doi.org/10.1007/978-4-431-54052-6_9.
Full text
2
Fleurance, G., N. Edouard, C. Collas, P. Duncan, A. Farruggia, R. Baumont, T. Lecomte, and B. Dumont. "How do horses graze pastures and affect the diversity of grassland ecosystems?" In Forages and grazing in horse nutrition, 147–61. Wageningen: Wageningen Academic Publishers, 2012. http://dx.doi.org/10.3920/978-90-8686-755-4_16.
Full text
3
Tuvshintogtokh, Indree, and Dorjgotov Ariungerel. "Degradation of Mongolian Grassland Vegetation Under Overgrazing by Livestock and Its Recovery by Protection from Livestock Grazing." In The Mongolian Ecosystem Network, 115–30. Tokyo: Springer Japan, 2012. http://dx.doi.org/10.1007/978-4-431-54052-6_10.
Full text
4
Davidson, Eric A., Donald J. Herman, Ayelet Schuster, and Mary K. Firestone. "Cattle Grazing and Oak Trees as Factors Affecting Soil Emissions of Nitric Oxide from an Annual Grassland." In Agricultural Ecosystem Effects on Trace Gases and Global Climate Change, 109–19. Madison, WI, USA: American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, 2015. http://dx.doi.org/10.2134/asaspecpub55.c7.
Full text
5
Hamilton, Richard. "A Rancher’s Eye View of Grazing Native Grasslands in California." In Managing for Healthy Ecosystems. CRC Press, 2002. http://dx.doi.org/10.1201/9781420032130.ch102.
Full text
6
Ward, David. "The Effects of Grazing on Plant Biodiversity in Arid Ecosystems." In Biodiversity in Drylands. Oxford University Press, 2005. http://dx.doi.org/10.1093/oso/9780195139853.003.0021.
Full textAbstract:
Conventional wisdom views heavy grazing as the major cause of desertification in semiarid and arid areas of Africa, Asia, and Australia (see, e.g., Acocks 1953, Jarman and Bosch 1973, Sinclair and Fryxell 1985, Middleton and Thomas 1997). Nowhere is the effect of heavy grazing more apparent than in the Sahel of Africa (Sinclair and Fryxell 1985). This land denudation has resulted in a negative feedback loop via decreased soil nutrient status and increased soil albedo (due to lower vegetation cover), causing increased evaporation and decreased precipitation, which in turn reduces the stocking capacity of the land, further exacerbating the negative effects of grazing (Schlesinger et al. 1990). A less dramatic result of overgrazing is a long-term decline in agricultural productivity. For example, the arid Karoo region of South Africa has experienced no climatic change over the last two centuries, yet there has been a 50% decline in stocking rates in seven of eight magisterial districts from 1911 to 1981 (Dean and McDonald 1994). These authors ascribe this decline to heavy grazing that reduced palatable plant populations and hence the carrying capacity of the vegetation in the long term. These examples of the negative effects of grazing in arid ecosystems lie in stark contrast with a large number of African studies that compared the effects of commercial (privately owned) and communal (subsistence, no private ownership) ranching on vegetation and soils (e.g., Archer et al. 1989, Tapson 1993, Scoones 1995, Ward et al. 1999a,b, reviewed by Behnke and Abel 1996). In spite of 5–10-fold higher stocking rates on communal ranches, few studies have shown differences in effects on biodiversity, plant species composition and soil quality between these ranching types (Archer et al. 1989, Tapson 1993, Scoones 1995, Ward et al. 1999a,b—fig. 14.1). Similarly, studies of grazing in Mediterranean semiarid grasslands (reviewed by Seligman 1996) and Middle Eastern arid rangelands (Ward et al. 1999b) show that the effects of grazing on biodiversity are relatively small. A consensus has developed in recent years that arid grazing ecosystems are nonequilibrial, event-driven systems (see, e.g., O’Connor 1985, Venter et al. 1989, Milchunas et al. 1989, Parsons et al. 1997).
7
Milchunas, Daniel G., and William K. Lauenroth. "Effects of Grazing on Vegetation." In Ecology of the Shortgrass Steppe. Oxford University Press, 2008. http://dx.doi.org/10.1093/oso/9780195135824.003.0020.
Full textAbstract:
Grazing by large native ungulates and semiaridity are the two main forces that have had a large infuence in shaping the current-day structure of the shortgrass steppe ecosystem (Milchunas et al., 1988). With the uplift of the Rocky Mountain chain during the Miocene (approximately one million years ago), forests of the Great Plains were gradually replaced by grasslands (Axelrod, 1985). Large grazing and browsing animals inhabited the Great Plains during the middle to late Pleistocene, as did grasses of the genera Stipa, Agropyron, Oryzopsis, and Elymus (Axelrod, 1985; Stebbins, 1981). Bison occurred both east and west of the Rockies during the Wisconsin glacial period in the latter part of the Pleistocene (Wilson, 1978). During the early Holocene, approximately 10,000 years ago, bison and grasses of the genera Bouteloua, Buchloë, Andropogon or Schizachyrium, and Sorghastrum concomitantly increased throughout the Great Plains (Stebbins, 1981), but bison did not proliferate west of the continental divide (Mack and Thompson, 1982; Van Vuren, 1987). The natural shift in fauna from horses, pronghorn, and camels to bison and wild sheep from Eurasia is thought to have favored the spread of shortgrasses such as Bouteloua and Buchloë (Stebbins, 1981). Furthermore, grassland flora east and west of the Rocky Mountains probably had separate origins (Leopold and Denton, 1987). The shortgrass steppe is unique from other North American semiarid ecosystems in having bison play an important role. Bison did not proliferate west of the Rocky Mountains as they did on the Great Plains to the east. This is due in part to a lack of coincidence in timing of bison lactation and the phenological development of C3 grasses in the more Mediterranean–like climate west of the Rockies, in contrast to the mix of C3 and C4 grasses and pattern of spring–summer precipitation on the Great Plains (Mack and Thompson, 1982). Other explanations for the low numbers of bison west of the Rocky Mountains include physiographic barriers restricting immigration (Kingston, 1932), low p rotein content of forage (Daubenmire, 1985; Johnson, 1951), heavy snowfall as a cause of mortality (Daubenmire, 1985), and low aboveground primary production coupled with disjunct suitable habitat (Van Vuren, 1987). Bison a lso did not prosper in the southwestern United States, nor did a large herbivore fauna develop in South America (Stebbins, 1981).
8
Monger, H. Curtis. "Millennial-Scale Climate Variability and Ecosystem Response at the Jornada LTER Site." In Climate Variability and Ecosystem Response in Long-Term Ecological Research Sites. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195150599.003.0032.
Full textAbstract:
The Jornada Long-Term Ecological Research (JRN LTER) program consists of studies superimposed on three research entities, the Jornada Experimental Range, the Chihuahuan Desert Rangeland Research Center, and the Desert Soil-Geomorphology project (figure 17.1). The JRN site is in the northern part of the Chihuahuan Desert and represents, for the LTER network, the desert shrubland and desert grassland ecosystems of the southwestern United States. Climate data at the Jornada site and surrounding area span the last 110 years. Ecological data span the last 144 years. Despite having over 100 years of data, researchers at the Jornada LTER have struggled to answer the focal question of this book: How have ecosystems responded to climatic variability? This is because, simultaneous with climate, another important factor has had a major impact on ecosystems—human land use. Cattle grazing, brush control, and habitat fractionation have merged with climate to produce external pressures on Jornada ecosystems (Schlesinger et al. 1990; Havstad et al. 2000). Even more uncertain is the cause-and-effect relationship between climate and ecosystems in prehistoric times. Here evidence is limited to indicators, such as former lake shorelines, plant fossils in packrat middens, fossil pollen, 13C/12C ratios in paleosols, and erosion rates. When some indicators are used by themselves, circularity arises if a conclusion about ecosystem response to climate change is based on an inference about climate change, which is based, in turn, on ecosystem change. For example, grasslands increased at the end of the middle Holocene as the result of increased rainfall, where the interpretation of increased rainfall is based on increased grass pollen in the middle Holocene sediments (Freeman 1972). Although focusing on millennial-scale climate and ecosystem variability, this chapter briefly discusses historic variability for comparison and as a means for describing the setting. The historic-prehistoric boundary for the Jornada area has been set at A.D. 1850 (table 17.1). Located at 32.5º N and 106.8º W, in New Mexico, USA, the Jornada LTER site is in the Basin and Range province (Peterson 1981), which is characterized by parallel mountain ranges separated by structural basins filled with Cenozoic sediments (Hawley 1986). Elevations at the Jornada range from 1,180 m (3,870 ft) in the Rio Grande floodplain to 2,749 m (9,012 ft) in the Organ Mountains.
9
Burke, Ingrid C., and William K. Lauenroth. "The Future of the Shortgrass Steppe." In Ecology of the Shortgrass Steppe. Oxford University Press, 2008. http://dx.doi.org/10.1093/oso/9780195135824.003.0023.
Full textAbstract:
Where lies the future of the shortgrass steppe? In prior chapters we have described the remarkable resilience of the shortgrass steppe ecosystem and its organisms to past drought and grazing, and their sensitivity to other types of change. Emerging from this analysis is the idea of vulnerability to two main forces: future changes in precipitation or water availability, and direct human impacts. What are the likely changes in the shortgrass steppe during the next several decades? Which of the changes are most likely to affect major responses in the plants, animals, and ecosystem services of the shortgrass steppe? In this chapter we evaluate the current status of the shortgrass steppe and its potential responses to three sets of factors that will be driving forces for the future of the steppe: land-use change, atmospheric change, and changes in diseases. Referring to the early 1900s, James Michener in his novel Centennial (1974) wrote the following:… The old two-part system that had prevailed at the end of the nineteenth century— rancher and irrigator—was now a tripartite cooperation: the rancher used the rougher upland prairie; the irrigation farmer kept to the bottom lands; and the drylands gambler plowed the sweeping 0 eld in between, losing his seed money one year, reaping a fortune the next, depending on the rain. It was an imaginative system, requiring three different types of man, three different attitudes toward life. . . . (p. 1081)… Even today, because of the strong water limitation for cropping, the shortgrass steppe remains relatively intact, or at least unplowed, in contrast to other grassland ecosystems (Samson and Knopf, 1994). More than half of the shortgrass steppe remains in untilled, landscape-scale tracts, compared with only 9% of tallgrass prairie and 39% of mixed-grass prairie (The Nature Conservancy, 2003). These large tracts, including those in the national grasslands (Pawnee, Cimarron, Comanche, and Kiowa/Rita Blanca), provide the greatest opportunity for preserving key ecological processes and biological diversity.
10
Allen, Harriet. "Vegetation and Ecosystem Dynamics." In The Physical Geography of the Mediterranean. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780199268030.003.0019.
Full textAbstract:
Within the Mediterranean region a number of distinctive vegetation communities can be recognized, comprising some 25,000 species, of which about 50 per cent are endemic. Broadly defined, these originated with the establishment of a mediterranean-type climate about 3.2 million years ago, since when they have been subject to the vicissitudes of glacial–interglacial climate changes, plus the intensification of human impact during the last 10,000 years (Chapters 4 and 9). These communities are dynamic, responding to environmental changes at a variety of scales, both spatial and temporal. This chapter explores the characteristics of these communities and examines the relationships between ecosystem dynamics and biodiversity, and ecosystem response to disturbance. For example, each year fires burn out of control and are the subject of regular news stories during summer months. While fires may be economically devastating and lead to loss of life (Chapter 19), ecologically their incidence is an important dynamic component of Mediterranean ecosystems and may, indeed, be crucial to the successful propagation and spread of plants and communities regarded as typically Mediterranean. Associated animal populations generally recover quickly despite inevitable loss of life in some populations. Thus understanding the role of fire and other disturbance factors such as grazing is key to understanding Mediterranean vegetation communities and ecosystem dynamics. The chapter concludes with an evaluation of the likely response of vegetation communities to potential atmospheric and land use changes. While a number of distinct vegetation communities have been identified, a common characteristic is an ability to survive hot, dry summers and cool, wet winters, together with frequent disturbances. Many of the communities are dominated by shrubs, and Mediterranean evergreen sclerophyllous shrublands are recognized as one of the defined ecosystems of the world (di Castri 1981). Such shrublands are at the centre of a continuum of communities which vary along gradients of moisture availability, temperature, and nutrient availability, usually determined by substrate, and human activity. At the extreme ends of these gradients, but still Mediterranean, are sclerophyllous woodlands, coniferous and deciduous forests, savannas and grasslands grading into steppe and semi-desert shrublands, and heathlands.