Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 23 of 23
Full-Text Articles in Physical Sciences and Mathematics
Grazing Effects On Soil Seed Banks: A Global Synthesis, Shi Yafei
Grazing Effects On Soil Seed Banks: A Global Synthesis, Shi Yafei
IGC Proceedings (1997-2023)
Livestock grazing is a major disturbance affecting plant diversity and abundance in terrestrial ecosystems. The intermediate disturbance hypothesis (IDH) predicts that moderate-intensity grazing should produce the highest species diversity, while the Milchunas-Sala-Lauenroth (MSL) model posits that the IDH is valid only for mesic areas. However, it remains unclear how grazing affects soil seed bank and whether or not the IDH or MSL models are valid for soil seed bank communities. Here, we presented a global meta-analysis synthesizing 483 observations: we found that grazing had a negative effect on soil seed bank abundance, but did not alter seed bank richness. Further …
Back To The Future: How Do We Get There From Here? Making Restoration Work, K. Swilling, E. Bisangwa, Pat D. Keyser
Back To The Future: How Do We Get There From Here? Making Restoration Work, K. Swilling, E. Bisangwa, Pat D. Keyser
IGC Proceedings (1997-2023)
Extreme temperatures and long periods of drought observed with increasing frequency in the southeastern United States (U.S.) have demonstrated the need to develop more robust forage systems. Native warmseason grasses (NWSGs) are well adapted to fill this role, but their expanded use comes with several challenges, most notably, reliable establishment. The high cost of site preparation, high cost of seed, and slow initial growth of NWSG seedlings must be addressed to achieve increased adoption of NWSG in the eastern U.S. If these challenges are overcome, incorporating NWSG into grazing systems would benefit producers by filling the summer forage gap, mitigating …
Grazing Effects On Soil Seed Banks: A Global Synthesis, Shi Yafei
Grazing Effects On Soil Seed Banks: A Global Synthesis, Shi Yafei
IGC Proceedings (1997-2023)
Livestock grazing is a major disturbance affecting plant diversity and abundance in terrestrial ecosystems. The intermediate disturbance hypothesis (IDH) predicts that moderate-intensity grazing should produce the highest species diversity, while the Milchunas-Sala-Lauenroth (MSL) model posits that the IDH is valid only for mesic areas. However, it remains unclear how grazing affects soil seed bank and whether or not the IDH or MSL models are valid for soil seed bank communities. Here, we presented a global meta-analysis synthesizing 483 observations: we found that grazing had a negative effect on soil seed bank abundance, but did not alter seed bank richness. Further …
Effect Of Land Management On Grassland Carbon Dioxide Fluxes, M. O’Neill, S. F. Islam, J. Rambaud, G. J. Lanigan, K. G. Richards, M. B. Lynch
Effect Of Land Management On Grassland Carbon Dioxide Fluxes, M. O’Neill, S. F. Islam, J. Rambaud, G. J. Lanigan, K. G. Richards, M. B. Lynch
IGC Proceedings (1997-2023)
Grassland soils can act as both a source and sink for atmospheric carbon dioxide (CO2). Implementing grassland management practices that increase the rates of soil CO2 sequestration are urgently sought to offset Ireland’s agricultural greenhouse gas emissions. However, land management of Irish grasslands is not yet accounted for in the national inventories simultaneously posing a limitation and opportunity for refining modelled estimates of carbon sequestration. In this study, eddy covariance flux towers were established to monitor net ecosystem CO2 exchange (NEE), gross primary productivity (GPP) and ecosystem respiration (Re) in three grassland types (intensive dairy grazing, drystock grazing and zero- …
Biodiversity And The Ecological Role Of Grasslands Environment And Territory, Elimane Lo, Makhmutov Serguei, Badim Almazov
Biodiversity And The Ecological Role Of Grasslands Environment And Territory, Elimane Lo, Makhmutov Serguei, Badim Almazov
IGC Proceedings (1997-2023)
Biodiversity is all the living species that inhabit the planet: plants, animals, microorganisms, but also their genetic diversity and all the ecosystems in which they live. The preservation of biodiversity is vital, because the organisms that constitute it participate in the major ecological cycles of air, soil and water It is today recognized for its intrinsic value and for the functions it provides in ecosystems. The grassland and the hedges that surround them play a key role in carbon storage, water purification, biodiversity and the typicity of landscapes. They partly provide the plants necessary for feeding herds of herbivores (cattle, …
Back To The Future: Achieving Resilient, Sustainable Grasslands Through Restoration Of Ecological Norms / Overview – The Problem, The Opportunity, Pat D. Keyser, C. Bitler
Back To The Future: Achieving Resilient, Sustainable Grasslands Through Restoration Of Ecological Norms / Overview – The Problem, The Opportunity, Pat D. Keyser, C. Bitler
IGC Proceedings (1997-2023)
Grasslands are one of the largest biomes on earth, are the largest agricultural enterprise in the U.S., serve as a major carbon pool, produce high quality dietary proteins, and host a rich biodiversity. However, grasslands, including those of the eastern U.S., have been heavily altered and degraded reducing their resiliency and negatively impacting native fauna. Recent scientific advances in grassland establishment and management, along with the opportunity to monetize the carbon benefits of native grasslands, could provide the needed social and economic support to make such restoration possible on a large scale. Where restored grassland communities align with historical, ecological …
L-Grassf: A New Model For Simulating The Genetic Environment Interactions On The Reproductive Phenology Of Grasses, S. Rouet, Jean Louis Durand, D. Combes, A. Escobar Gutiérrez, D. Leclercq, R. Barillot
L-Grassf: A New Model For Simulating The Genetic Environment Interactions On The Reproductive Phenology Of Grasses, S. Rouet, Jean Louis Durand, D. Combes, A. Escobar Gutiérrez, D. Leclercq, R. Barillot
IGC Proceedings (1997-2023)
Predicting the reproductive phenology in perennial grasses is a major concern because it determines the quantity and quality of forage. It varies a lot depending on site, year and cultivar. Projections of future climates suggest significant changes in seasonal temperature pattern, with new combinations of temperature and photoperiod, whose consequences on the floral induction of perennial grasses are unknown. L-GrassF is a new Functional Structural Plant Model simulating genetic variability of the phenology of perennial ryegrass in order to better understand the perenniality of grasslands and better anticipate the effects of climate change. L-GrassF stems from a previous model (L-Grass) …
The Soil Health Properties Of Native Grasslands, C. Bitler, Pat Keyser
The Soil Health Properties Of Native Grasslands, C. Bitler, Pat Keyser
IGC Proceedings (1997-2023)
Due to an increased interest in soil health and the role soils can have in carbon sequestration, native grasslands are getting heightened attention. Native grasslands are known for their deep top-soils that develop over time through the accumulation of soil organic matter. The deep and fibrous root systems that make up two-thirds of the biomass of native grasslands are the primary contributors to the soil organic carbon (SOC) content of grassland soils. Increased SOC content has a cascading effect on soil health metrics through increasing water infiltration and water holding capacity, supporting diverse and abundant soil microbial life, and improving …
Modelling Basal Area Of Perennial Grasses In Australian Semi-Arid Wooded Grasslands, S. G. Marsden, K. C. Hodgkinson
Modelling Basal Area Of Perennial Grasses In Australian Semi-Arid Wooded Grasslands, S. G. Marsden, K. C. Hodgkinson
IGC Proceedings (1997-2023)
In many semi-arid pastoral systems, landscape processes easily become dysfunctional. Shifts to less functional states may be irreversible, and have long-term consequences for pastoral profitability and social viability of rural communities. Typically, shifts to lower functional states involve a decline in perennial grasses (Hodgkinson, 1994). Here we develop a conceptual basis for modelling the basal area of perennial grasses in a semi-arid grassland and validate the model using data from a 10-year grazing study.
Does Niche Complementarity Explain The Relationship Between Biodiversity And Ecosystem Functioning In Managed Grasslands?, Nina Buchmann, A. Kahmen
Does Niche Complementarity Explain The Relationship Between Biodiversity And Ecosystem Functioning In Managed Grasslands?, Nina Buchmann, A. Kahmen
IGC Proceedings (1997-2023)
Niche complementarity was suggested to largely explain the positive relationship noted between plant diversity and productivity in some recent studies. This suggests that an increasing number of species exploits resources more efficiently and thus enhance ecosystem functions. This hypothesis, however, implies that niches occupied by different plant species are rather distinct so that niches from extinct or missing species stay unoccupied by the remaining species of an ecosystem. This experiment tested if plant species occupy different and distinct niches with respect to soil N uptake, being a possible functional explanation for the biodiversity ecosystem functioning relationship.
The Use Of Ecological Indicators In Studies Of Ecological Recovery For Sustainable Management Of Grazed Grassland Ecosystems, G. A. Heshmati
The Use Of Ecological Indicators In Studies Of Ecological Recovery For Sustainable Management Of Grazed Grassland Ecosystems, G. A. Heshmati
IGC Proceedings (1997-2023)
Early warning systems that depend on the selection of suitable indicators of thresholds are useful (Friedel, 1991). An ideal indicator should be unbiased, sensitive to changes, predictive, referenced to threshold values, data transformable, integrative and easy to collect and communicate (Liverman et al., 1988). Methods for selection of indicators for assessing ecosystem health are being developed (Pyke et al., 2002). This paper examines the situation in grassland vegetation grazed by sheep in a semi arid region of northeastern Iran.
Undp-Gef Grasslands Project: Conserving Mountain Biodiversity In Southern Lesotho, W. A. Rodgers
Undp-Gef Grasslands Project: Conserving Mountain Biodiversity In Southern Lesotho, W. A. Rodgers
IGC Proceedings (1997-2023)
The Kingdom of Lesotho contains some 70% of the Drakensberg-Maloti Mountains, recognised as the Eastern Mountains "Centre of Biodiversity and Endemism" of southern Africa. The Mountains have globally significant plant diversity, with unique habitats and high endemism. These resources have been increasingly degraded by a grazing regime based on communal access, with reduced regulatory capability. Lack of ownership has restricted investment in conservation. Lesotho has the lowest Protected Area coverage of any nation in Africa (<0.4%). Biodiversity is thus at risk.
Undp-Gef Grasslands Project: Mainstreaming Biodiversity Into Productive Landscapes: The Southern African Grasslands Programme, C. Maze, W. A. Rodgers
Undp-Gef Grasslands Project: Mainstreaming Biodiversity Into Productive Landscapes: The Southern African Grasslands Programme, C. Maze, W. A. Rodgers
IGC Proceedings (1997-2023)
This is an exciting new initiative under the second strategic priority for the Global Environment Programme (GEF)'s Biodiversity Focal Area: Mainstreaming biodiversity into productive landscapes and sector. The rationale is that whilst grassland biomes cover some 30% of South Africa, (within montane, coastal and high-veld systems) less than 3% is formally protected at national, provincial or private land-owner levels. Over 40% of the grasslands have been totally converted to other land usages and 30% is degraded. Forces of degradation and conversion (cultivation, forests, urban spread) continue. The issues of conservation are of land use and putting in place incentives to …
Undp-Gef Grasslands Project: The Tanzania Montane Grasslands Project, T. Davenport, W. A. Rodgers
Undp-Gef Grasslands Project: The Tanzania Montane Grasslands Project, T. Davenport, W. A. Rodgers
IGC Proceedings (1997-2023)
The Tanzania Southern Highlands and adjacent Nyika montane grasslands in Malawi form a distinct centre of plant diversity and endemism. The area is characterised by complex geology with old basement mountains and much more recent volcanoes (Mount Rungwe) adjacent to the rift valet faulting with Lakes Malawi (Nyasa) and Rukwa. Lake proximity generates rainfall up to 3,000 mm per annum. The maximum altitude is 3,000 m asl.
Sustaining Grass-Legume Pastures For Cow-Calf Herds: A Case Study, John L. Caddel, D. D. Redfearn, R. L. Woods
Sustaining Grass-Legume Pastures For Cow-Calf Herds: A Case Study, John L. Caddel, D. D. Redfearn, R. L. Woods
IGC Proceedings (1997-2023)
An on-going pasture demonstration study has been used since 1988 to demonstrate methods to improve pasture production for small beef cow-calf herds. Many cattle enterprises are not economically viable because poor management decisions lead to excessive stocking rate, ineffective fertilisation programmes etc., leading to a dependence on hay purchases. The initial objective, continued until 2001, was to maintain one cow- calf pair per ha without purchasing forage or grain produced off farm. More recently, reducing the dependence on harvested forage has been added as an objective.
Use Of Forage Legumes To Restore Overgrazed Natural Grasslands In Uganda, Elly N. Sabiiti, S. Mugasi, F. B. Bareeba
Use Of Forage Legumes To Restore Overgrazed Natural Grasslands In Uganda, Elly N. Sabiiti, S. Mugasi, F. B. Bareeba
IGC Proceedings (1997-2023)
The natural grasslands of Uganda support over 95 % of the country's livestock. They are also used by wildlife and protect soil resources from heat and erosion. Unfortunately, the pastoral/agro-pastoral communities which derive their livelihoods from these grasslands have in turn degraded them through overgrazing and uncontrolled burning, thus lowering their productivity (pasture and animal production) and biodiversity. The natural grasses (e.g. Panicum maximum, Brachiaria brizantha, Setaria anceps, Themeda triandra) mature rapidly and lose quality. Furthermore, the indigenous legumes (e.g. Neonotonia wightii, Desmodium adcsendens, Indigofera errecta) are less persistent and productive to maintain feed quality and hence animal …
Potentialities Of Near Infrared Spectroscopy To Assess Nitrogen, Phosphorus And Potassium Nutrient Status Of Grasslands In The Reunion Island, Philippe Lecomte, Vincent Blanfort, Michael Duru, P. Thomas, P. Grimaud
Potentialities Of Near Infrared Spectroscopy To Assess Nitrogen, Phosphorus And Potassium Nutrient Status Of Grasslands In The Reunion Island, Philippe Lecomte, Vincent Blanfort, Michael Duru, P. Thomas, P. Grimaud
IGC Proceedings (1997-2023)
Controlled mineral fertilisation practices are an important component for sustainable management of grasslands. The assessment of available nutrients for plants and the general recommendations on the level of phosphorus and potassium to apply to grasslands are classically based on classical soil analysis and average regional levels. For nitrogen, mid or long term recommendations cannot easily be derived solely from soil composition, because it may be rapidly leached from the soil. Recent approaches tended to show that herbage plant N (Lemaire & Gastal, 1997), P, K (Duru & Huché, 1997) mineral analyses associated with actual biomass measurement could be useful for …
Sheep Grazing During Drought Collapses The Perennial Grass Resource In Australian Semiarid Wooded Grasslands, K. C. Hodgkinson, S. G. Marsden, W. J. Muller
Sheep Grazing During Drought Collapses The Perennial Grass Resource In Australian Semiarid Wooded Grasslands, K. C. Hodgkinson, S. G. Marsden, W. J. Muller
IGC Proceedings (1997-2023)
Grazing of sheep in arid grasslands is risky; sudden shifts to lower functional states may occur when the ecosystem is stressed (Scheffer et al., 2001). To avoid the stresses that shift states, easy-to-recognise critical thresholds need to be identified (Westoby et al., 1989). Preliminary analysis of perennial grass survival in a drought indicated a critical threshold based on co-occurrence of drought and grazing. Crossing this threshold collapses grass populations (Hodgkinson, 1994). Here we examine the relationships between basal area change and rainfall and grazing levels based on a 10-year period and propose a management guideline.
The Effect Of Topographic Factors On The Productivity Of Mountain Grasslands In Northwestern Benin, T. H. Avohou, Brice Sinsin
The Effect Of Topographic Factors On The Productivity Of Mountain Grasslands In Northwestern Benin, T. H. Avohou, Brice Sinsin
IGC Proceedings (1997-2023)
The Atacora mountains range in northern Benin (660 m altitude) is a special ecosystem in the sudanian zone because of the overriding importance of topographic factors and shallow soils. The vegetation over this mountain range consists of shrub and tree savannas, woodlands and fallows. More and more cattle herds graze on this range. But the functioning of this ecosystem is still unknown like many others in the tropical zone (Sene & Zingari, 2001). This study aims to determine the impact of topography and mountain side exposure on the productivity of the Atacora mountains grasslands in the Atacora mountains.
Productivity Of Sahiwal And Friesian-Sahiwal Crossbreds In Marginal Grasslands Of Kenya, W. B. Muhuyi, F. B. Lukibisi, S. N. Ole Sinkeet
Productivity Of Sahiwal And Friesian-Sahiwal Crossbreds In Marginal Grasslands Of Kenya, W. B. Muhuyi, F. B. Lukibisi, S. N. Ole Sinkeet
IGC Proceedings (1997-2023)
Dual-purpose cattle can be used to exploit the production potential of semi-arid grasslands of Kenya for milk and meat production. Although the Sahiwal is adapted to these grasslands, its productivity is low. In order to increase milk and meat productivity, the Sahiwal has been crossed with the Friesian to produce Friesian-Sahiwal crossbreds (McDowell et al., 1996) adapted to the tropical environment. The objective of this study was to evaluate the productivity of Sahiwal and Friesian-Sahiwal crossbreds.
Mortality Model For A Perennial Grass In Australian Semi-Arid Wooded Grasslands Grazed By Sheep, K. C. Hodgkinson, W. J. Muller
Mortality Model For A Perennial Grass In Australian Semi-Arid Wooded Grasslands Grazed By Sheep, K. C. Hodgkinson, W. J. Muller
IGC Proceedings (1997-2023)
Grazing of sheep in marginal semi-arid environments is risky because grazing appears to predispose grass plants, especially palatable species, to sudden death (Hodgkinson, 1994; 1995). These early observations were based on a preliminary analysis of perennial grass survival in a single drought and supported the concept of tactical grazing proposed by Westoby et al. (1989) as a preferred management. Later this idea was developed by suggesting the existence of critical thresholds for perennial grass survival, which when crossed, collapses grass populations (Hodgkinson, 1994). Here we examine the relationship between mortality of a palatable perennial grass, Thyridolepis mitchelliana, and a …
Productivity Of Sahiwal And Friesian–Sahiwal Crossbreds In Marginal Grasslands Of Kenya, W. B. Muhuyi, F. B. Lukibisi, S. N. Ole Sinkeet
Productivity Of Sahiwal And Friesian–Sahiwal Crossbreds In Marginal Grasslands Of Kenya, W. B. Muhuyi, F. B. Lukibisi, S. N. Ole Sinkeet
IGC Proceedings (1997-2023)
Dual-purpose cattle can be used to exploit the production potential of semi-arid grasslands of Kenya for milk and meat production. Although the Sahiwal is adapted to these grasslands, its productivity is low. In order to increase milk and meat productivity, the Sahiwal has been crossed with the Friesian to produce Friesian-Sahiwal crossbreds (McDowell et al., 1996) adapted to the tropical environment. The objective of this study was to evaluate the productivity of Sahiwal and Friesian-Sahiwal crossbreds.
Mortality Model For A Perennial Grass In Australian Semi-Arid Wooded Grasslands Grazed By Sheep, K. C. Hodgkinson, W. J. Muller
Mortality Model For A Perennial Grass In Australian Semi-Arid Wooded Grasslands Grazed By Sheep, K. C. Hodgkinson, W. J. Muller
IGC Proceedings (1997-2023)
No abstract provided.