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Articles 1 - 16 of 16
Full-Text Articles in Physical Sciences and Mathematics
Plant Diversity Patterns Along Altitudinal Gradient In Understory Communities Of Darkesh Region, Bojnord, Iran, A. Arjmandi, H. Ejtehadi, F. Memariani, Mansour Mesdaghi
Plant Diversity Patterns Along Altitudinal Gradient In Understory Communities Of Darkesh Region, Bojnord, Iran, A. Arjmandi, H. Ejtehadi, F. Memariani, Mansour Mesdaghi
IGC Proceedings (1997-2023)
The ecotone region of Darkesh with an area of 22,500 hectares is located in the Irano-Turanian xeric-continental bioclimatic zone of Khorassan-Kopet Dagh. To investigate the plant diversity patterns of understory communities along three elevation classes of 1100-1600, 1600-2100, and 2100-2600 m, 187 plots were sampled randomly and abundance and cover of species were recorded using 4-m2 plots. Beta diversity and Hill indices were calculated by using R and PAST software. A total of 252 species were recorded including 31 perennial grasses. The most abundant grasses were Poa nemoralis, Poa bulbosa, Bromus sterilis, Brachypodium sylvaticum, and Dactylis glomerata subsp. glomerata …
Effects Of Plant Species Diversity In Multifunctional Grasslands On Avian Communities, K. K. Bakker, K. F. Higgins
Effects Of Plant Species Diversity In Multifunctional Grasslands On Avian Communities, K. K. Bakker, K. F. Higgins
IGC Proceedings (1997-2023)
Grasslands, planted or native sod, can provide multiple simultaneous functions (e.g., hay-forage production, biomass fuel products, bird nesting cover, soil and water conservation). Bird use of and abundance in grasslands is dependent on vegetation structure, size, and surrounding landscape (Bakker et al., 2002) but little is known about avian relationships to plant species diversity. We evaluated the relationship between plant species diversity and avian community structure in 5 grassland types. The results have application to grazing, haying, burning, and conservation practices applied to native and sown grassland stands and to conservation strategies for declining grassland bird populations.
Forage And Livestock Productivity On Pastures Of Differing Plant Diversity, B. F. Tracy
Forage And Livestock Productivity On Pastures Of Differing Plant Diversity, B. F. Tracy
IGC Proceedings (1997-2023)
Plant diversity and its function in grassland ecosystems has been the focus of many recent studies, and debate, in the ecological literature (Wardle 1999, Loreau and Hector 2001). We know less about the role of plant diversity in pastures used solely for agricultural production (Sanderson et al. 2004). The objective of this study was to learn how pastures planted with increasing levels of plant diversity would affect forage yields and beef cattle performance.
Maintaining Grassland Plant Diversity While Controlling Woody Plant Encroachment, James Stubbendieck, Kay L. Kottas, S. J. Tunnell, S. J. Palazzolo
Maintaining Grassland Plant Diversity While Controlling Woody Plant Encroachment, James Stubbendieck, Kay L. Kottas, S. J. Tunnell, S. J. Palazzolo
IGC Proceedings (1997-2023)
The tallgrass prairie region of the United States is a fragmented grassland ecosystem. Much of the 1 to 2% of the remaining prairie is being degraded by invading woody plants, which frequently results in a shift from grassland to woodland. Smooth sumac (Rhus glabra L.), a shrub native to the region, can rapidly increase in density and become dominant in the plant community. Prescribed fire alone is not a constraint to this resprouting species (Stubbendieck et al., 2003). Herbicides are useful tools for managing woody plants in grasslands, but the negative response of desirable plants to herbicides is …
The Diversity Of Poisonous Plant Patches In The Arid Rangelands Of Namaqualand, South Africa, T. Jamalie, M. I. Samuels, C. F. Cupido, F. L. Müller, W. L. Engelbrecht, T. Dube, R. S. Knight
The Diversity Of Poisonous Plant Patches In The Arid Rangelands Of Namaqualand, South Africa, T. Jamalie, M. I. Samuels, C. F. Cupido, F. L. Müller, W. L. Engelbrecht, T. Dube, R. S. Knight
IGC Proceedings (1997-2023)
The Namaqualand region in South Africa is part of the richest arid biodiversity hotspot in the world. Plant distribution and diversity here are impacted by various biophysical and anthropogenic factors. In these landscapes, poisonous plant patches, which pose serious threats to livestock, are widespread but their contribution to the regions biodiversity are not fully understood. This study assessed their plant diversity and compared its matrix. This study was conducted in the semi-arid to arid Steinkopf pastoral area located in Namaqualand where livestock is still herded daily. Twenty-five paired sites were selected based on the dominance of poisonous plants within the …
Long Term Observation Of The Grassland Vegetation Used Intensively Or Extensively And Ecologically, H.-D. Matthes, J. Matthes, W. Jentsch, V. Pastushenko
Long Term Observation Of The Grassland Vegetation Used Intensively Or Extensively And Ecologically, H.-D. Matthes, J. Matthes, W. Jentsch, V. Pastushenko
IGC Proceedings (1997-2023)
The aim of the present paper was to study alterations of the grassland flora from 55 plots following a more extensive management under long term observation within 6 years. Extensification of grassland use leads to an increase of the numbers of plant species by 32%, “Red-list-species” included. The moisture number of the soils slightly increased and the reaction and nitrogen numbers decreased. Results are presented for different vegetation units.
Grassland Use And Plant Diversity In Grazed Ecosystems, V. A. Deregibus, E. J. Jacobo, O. E. Ansin
Grassland Use And Plant Diversity In Grazed Ecosystems, V. A. Deregibus, E. J. Jacobo, O. E. Ansin
IGC Proceedings (1997-2023)
Earth biomes are being deconstructed, through unprecedented rates of species disappearance or invasion (McCann 2000). This, added to the threat of global environmental change and changes in values of a developed society, caused that biodiversity became a topic that has captured the attention of the public as well as the scientific community. Such concern on the importance of biodiversity is based in four basic reasons clearly described by West (1993): (i) morality, that aims for the protection of species; (ii) aesthetics, as people desire to see and appreciate the living parts of nature; (iii) economics and, (iv) the array …
Choosy Grazers And Plant Communities – Interactions Between Cattle Breeds And Vegetation In Semi-Natural Pastures, C. M. Pauler, Johannes Isselstein, J. Berard, T. Braunbeck, M. K. Schneider
Choosy Grazers And Plant Communities – Interactions Between Cattle Breeds And Vegetation In Semi-Natural Pastures, C. M. Pauler, Johannes Isselstein, J. Berard, T. Braunbeck, M. K. Schneider
IGC Proceedings (1997-2023)
It is well recognized that domesticated and wild ruminant grazers have an important impact on the composition of grassland vegetation, mainly by forage selection, trampling and defaecation. However, little is known on the effects of genetic diversity, for example differences among breeds of cattle. Cattle breeds differ in terms of robustness, growth rate, weight and probably also in movement and forage selection behaviour, which all could impact vegetation composition. Our study therefore aimed at identifying breed-specific differences in forage selection and behaviour and its consequences for vegetation. In a controlled experiment on semi-natural pastures in the Swiss Alps, suckler cows …
Variation Of Plant Diversity And Feeding Value In Gurbantunggut Desert Grassland, Y. B. Qian, Z. N. Wu, L. Y. Zhang, H. Y. Zhang
Variation Of Plant Diversity And Feeding Value In Gurbantunggut Desert Grassland, Y. B. Qian, Z. N. Wu, L. Y. Zhang, H. Y. Zhang
IGC Proceedings (1997-2023)
No abstract provided.
Plant And Animal Responses To Different Grazing Regimes On A Meadow Steppe In Northeast China, Deli Wang, Zhiming Yang, Ling Wang
Plant And Animal Responses To Different Grazing Regimes On A Meadow Steppe In Northeast China, Deli Wang, Zhiming Yang, Ling Wang
IGC Proceedings (1997-2023)
Grazing by domestic herbivores is often considered to be an essential factor governing grassland vegetation and animal production (Hodgson and Illius 1996). During recent decades, there is increasing interest as a fundamental interaction between plant-animal interface, especially for the simultaneous or interactive responses of plants and animals to grassland grazing regimes (Liu et al., 2015), which benefits on improving the efficiency of grazing or grassland resource management. To achieve sustainable animal productivity and maintain the stability of grasslands, farmers or stakeholders need to employ optimal grazing strategies or regimes based on practical grassland vegetation and environments. Unfortunately, up to date …
29 Years Of Vegetation Community Change Across Environmental Gradients In A Mojave Desert Mountain Range, Christopher L. Roberts, James S. Holland, Scott R. Abella
29 Years Of Vegetation Community Change Across Environmental Gradients In A Mojave Desert Mountain Range, Christopher L. Roberts, James S. Holland, Scott R. Abella
Graduate Research Symposium (GCUA) (2010 - 2017)
There is a great deal of uncertainty as to how biological communities respond to changes in land use and climate change, a situation particularly relevant in protected areas such as national parks that were designated to conserve specific biological features. Utilizing extant vegetation data sets with repeatable methodology can provide opportunities for insight into previous vegetation change and provide base line data for long-term monitoring projects useful for modeling vegetation community trajectories. We have relocated and resurveyed 106 sites from a vegetation community study initiated in 1979 in the Newberry Mountains, southern Nevada, within Lake Mead National Recreation Area managed …
Species Richness And Soil Properties In Pinus Ponderosa Forests: A Structural Equation Modeling Analysis, Daniel C. Laughlin, Scott R. Abella, W. Wallace Covington, James B. Grace
Species Richness And Soil Properties In Pinus Ponderosa Forests: A Structural Equation Modeling Analysis, Daniel C. Laughlin, Scott R. Abella, W. Wallace Covington, James B. Grace
Public Policy and Leadership Faculty Publications
Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest ecosystem. We evaluated multivariate models of plant species richness using structural equation modeling. Results: Richness was highest at intermediate levels of understory plant cover, suggesting that both colonization success and competitive exclusion can limit richness in this system. We did not detect a reciprocal positive …
Forest-Floor Treatments In Arizona Ponderosa Pine Restoration Ecosystems: No Short-Term Effects On Plant Communities, Scott R. Abella, W. Wallace Covington
Forest-Floor Treatments In Arizona Ponderosa Pine Restoration Ecosystems: No Short-Term Effects On Plant Communities, Scott R. Abella, W. Wallace Covington
Public Policy and Leadership Faculty Publications
Leaf litter accumulation during fire exclusion and increases in tree density in postsettlement southwestern Pinus ponderosa forests may limit the establishment of understory vegetation. We performed an experiment in P. ponderosa forests of northern Arizona to ascertain plant community responses to forest-floor scarification and Oi removal on thirty-six 100-m2 plots overlaid on an existing ecological restoration experiment that involved tree thinning and prescribed burning. Constrasting with findings from many other forest types, forest-floor treatments had no effect on community diversity or composition during the 2-year experiment. Sørensen similarities were as high as 97% between posttreatment years within treatments; and successional …
Understory Species Patterns And Diversity In Old-Growth And Managed Northern Hardwood Forests, Robert M. Scheller, David J. Mladenoff
Understory Species Patterns And Diversity In Old-Growth And Managed Northern Hardwood Forests, Robert M. Scheller, David J. Mladenoff
Environmental Science and Management Faculty Publications and Presentations
Forest management can significantly affect both the diversity and spatial patterning of understory vegetation. However, few studies have considered both diversity and spatial patterning at a stand scale. Our objective was to evaluate the effects of forest management on understory plant communities in northern hardwood forests and assess the processes governing differences in species composition, diversity, and spatial patterns. We sampled understory vegetation (all speciestall) and percentage of light transmission levels in three forest types in 12 mesic northern hardwood stands in northern Wisconsin and the Upper Peninsula of Michigan, USA: old-growth, undisturbed forests; even-aged forests resulting from clearcut logging …
Spatial And Temporal Patterns Of Eastern White Pine Regeneration In The Northwestern Ohio Oak Stand, Scott R. Abella, Neil W. Macdonald
Spatial And Temporal Patterns Of Eastern White Pine Regeneration In The Northwestern Ohio Oak Stand, Scott R. Abella, Neil W. Macdonald
Public Policy and Leadership Faculty Publications
Eastern white pine (Pinus strobus L.) was often associated with oaks (Quercus spp.) on upland sites in presettlement forests of the upper Great Lakes region, but widespread logging and subsequent fires in the late 1800s converted these upland sites to fire-tolerant oak forests. Although white pine regeneration is occurring in these second-growth oak forests, white pine regeneration patterns in oak forests of the Great Lakes region are not well documented. We examined white pine regeneration in the southern Great Lakes region in an oak stand within the Oak Openings region of northwestern Ohio, where white pine plantations established in the …
Multiple Source Pools And Dispersal Barriers For Galápagos Plant Species Distribution, J. Alan Yeakley, John F. Weishampel
Multiple Source Pools And Dispersal Barriers For Galápagos Plant Species Distribution, J. Alan Yeakley, John F. Weishampel
Environmental Science and Management Faculty Publications and Presentations
We reexamined geographic factors explaining the number of plant species on islands in the Galápagos Archipelago. We hypothesized that plant species richness (S) was related to the number of source pools and that plant species dispersal preferentially followed direct, oceanic pathways. To test different dispersal pathways from multiple source pools, the total number of islands within a given dispersal radius (i) was posed as the sum of the number of line-of-sight islands (Ci) and of the number of islands without line-of sight connection (Bi). In partial regression analyses, controlling for nearest island area (A2) …