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2012

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Articles 1 - 30 of 39

Full-Text Articles in Forest Sciences

An Assessment Of The Effects Of Desertification In Yobe State, Nigeria, Jibril Musa Phd Dec 2012

An Assessment Of The Effects Of Desertification In Yobe State, Nigeria, Jibril Musa Phd

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

Desertification is one of the most serious environmental and socio-economic problems of our time. Desertification describes circumstances of land degradation in arid, semi-arid and dry sub-humid regions resulting from the climatic variation and human activities. The fundamental goal of this thesis was to assess the effects of desertification in Yobe State, Nigeria. The present threat of desertification in the sahel has reached an alarming stage where crops cultivation and animal rearing/grazing are no more productive, soil has lost its nutrient/fertility, various infrastructure had given way because of windstorm from the neighbouring Niger Republic and sand dunes had taken over. The …


Buried Clay Pipe Irrigation, David A. Bainbridge Dec 2012

Buried Clay Pipe Irrigation, David A. Bainbridge

David A Bainbridge

The buried clay pipe method of irrigation is one of the most efficient systems known and is ideal for gardeners and small farmers. Buried clay pipe irrigation uses a buried, unglazed clay pipe filled with water to provide controlled irrigation to plants as the water seeps out through the clay wall at a rate that is influenced by the plant's water use. It has been used for more than one hundred years.This auto-regulation leads to very high efficiency--considerably better than drip irrigation and many times better than conventional surface irrigation. This also reduces weeds, increases yields, and can speed maturity …


Using Remote Sensing Data To Improve Rice Production In Kutigi, Niger State, Nigeria, Jibril Musa Phd, M B. Yunusa Dec 2012

Using Remote Sensing Data To Improve Rice Production In Kutigi, Niger State, Nigeria, Jibril Musa Phd, M B. Yunusa

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

This research work looked in the used of Remote Sensing to improve Agricultural production in Kutigi, Niger State. The aim of the study is to use remote sensing to improve rice farming activities in Kutigi, Niger State. It is very important to identify such methods to improve Agricultural production because experts are always interested in new researches and findings to better the standard of living in any environment. In view of this, Remotely-sensed data could be used or employed to elevate most of these agricultural problems in Kutigi through the following objectives: Using Landsat imagery to assess the present landuse …


Variations In Climatic Parameters And Food Crop Yields: Implications On Food Security In Benue State, Nigeria., Emmanuel Adamgbe, Fanan Ujoh Oct 2012

Variations In Climatic Parameters And Food Crop Yields: Implications On Food Security In Benue State, Nigeria., Emmanuel Adamgbe, Fanan Ujoh

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

Agricultural production in Nigeria like in other developing countries is highly vulnerable to variations in climatic parameters which may have inverse or direct effect on the performance of food crops. This paper examines the patterns and trends of the variations in the climatic parameters and the implications of such variations on efficient yield rates of some food crops in Benue State using data on climatic variables (rainfall, temperature, sunshine) and the yield of some crops per hectare for 25 years (1986-2010). Data on the climatic variables were collected from the Nigerian Meteorological Agency, AirForce Base, Makurdi while the data on …


Effects Of Atmospheric Nitrogen Deposition On The Herbaceous Layer Of A Central Appalachian Hardwood Forest, Frank S. Gilliam, Anne W. Hockenberry, Mary Beth Adams Sep 2012

Effects Of Atmospheric Nitrogen Deposition On The Herbaceous Layer Of A Central Appalachian Hardwood Forest, Frank S. Gilliam, Anne W. Hockenberry, Mary Beth Adams

Frank S. Gilliam

Additions of nitrogen (N) have been shown to alter species diversity of plant communities, with most experimental studies having been carried out in communities dominated by herbaceous species. We examined seasonal and inter-annual patterns of change in the herbaceous layer of two watersheds of a central Appalachian hardwood forest that differed in experimental treatment. This study was carried out at the Fernow Experimental Forest, West Virginia, using two adjacent watersheds: WS4 (mature, second-growth hardwood stand, untreated reference), and WS3. Seven circular 0.04-ha sample plots were established in eachwatershed to represent its full range of elevation and slope aspect. The herbaceous …


Effects Of Harvesting On Herbaceous Layer Diversity Of A Central Appalachian Hardwood Forest, Frank S. Gilliam Sep 2012

Effects Of Harvesting On Herbaceous Layer Diversity Of A Central Appalachian Hardwood Forest, Frank S. Gilliam

Frank S. Gilliam

Clearcutting is a common harvesting practice in many eastern hardwood forests. Among the vegetation strata of these forests, the herbaceous layer is potentially the most sensitive in its response to harvest-mediated disturbances and has the highest species diversity. Thus, it is important to understand the response of herbaceous layer diversity to forest harvesting. Previous work on clearcut and mature stands at the Fernow Experimental Forest (FEF), West Virginia, has shown that, although, harvesting did not alter appreciably herbaceous layer cover, it influenced the relationship of cover to biotic and abiotic factors, such as tree density and soil nutrients, respectively. The …


Temporal And Spatial Variation Of Nitrogen Transformations In Nitrogen-Saturated Soils Of A Central Appalachian Hardwood Forest, Frank S. Gilliam, Bradley M. Yurish, Mary Beth Adams Sep 2012

Temporal And Spatial Variation Of Nitrogen Transformations In Nitrogen-Saturated Soils Of A Central Appalachian Hardwood Forest, Frank S. Gilliam, Bradley M. Yurish, Mary Beth Adams

Frank S. Gilliam

We studied temporal and spatial patterns of soil nitrogen (N) dynamics from 1993 to 1995 in three watersheds of Fernow Experimental Forest, W.V.: WS7 (24-year-old, untreated); WS4 (mature, untreated); and WS3 (24-year-old, treated with (NH4)2SO since 1989 at the rate of 35 kg Nha–1year–1). Net nitrification was 141, 114, and115 kg Nha–1year–1, for WS3, WS4, and WS7, respectively, essentially 100% of net N mineralization for all watersheds. Temporal (seasonal) patterns of nitrification were significantly related to soil moisture and ambient temperaturein untreated watersheds only. Spatial patterns of soil water NO3–of WS4 suggest that microenvironmental variabilitylimits rates of N processing in …


The Ecological Significance Of The Herbaceous Layer In Temperate Forest Ecosystems, Frank Gilliam Sep 2012

The Ecological Significance Of The Herbaceous Layer In Temperate Forest Ecosystems, Frank Gilliam

Frank S. Gilliam

Despite a growing awareness that the herbaceous layer serves a special role in maintaining the structure and function of forests, this stratum remainsan underappreciated aspect of forest ecosystems. In this article I review and synthesize information concerning the herb layer’s structure,composition, and dynamics to emphasize its role as an integral component of forest ecosystems. Because species diversity is highest in the herb layeramong all forest strata, forest biodiversity is largely a function of the herb-layer community. Competitive interactions within the herb layer candetermine the initial success of plants occupying higher strata, including the regeneration of dominant overstory tree species. Furthermore, …


Vegetation And Acidification, David R. Dewalle, James N. Kochenderfer, Mary Beth Adams, Gary W. Miller, Frank S. Gilliam, Frederica Wood, Stephanie S. Odenwald-Clemens, William E. Sharpe Sep 2012

Vegetation And Acidification, David R. Dewalle, James N. Kochenderfer, Mary Beth Adams, Gary W. Miller, Frank S. Gilliam, Frederica Wood, Stephanie S. Odenwald-Clemens, William E. Sharpe

Frank S. Gilliam

In this chapter, the impact of watershed acidification treatments on WS3 at the Fernow Experimental Forest (FEF) and at WS9 on vegetation is presented and summarized in a comprehensive way for the first time. WS7 is used as a vegetative reference basin for WS3, while untreated plots within WS9 are used as a vegetative reference for WS9. Bioindicators of acidification impacts that will be considered include several measures of tree and stand growth rates, foliar chemistry, bolewood chemistry, and herbaceous species composition and diversity. These studies enhance our understanding of the inter-relationships of changes in soil conditions caused by the …


Effects Of Experimental Freezing On Soil Nitrogen Dynamics In Soils From A Net Nitrification Gradient In A Nitrogen-Saturated Hardwood Forest Ecosystem, Frank S. Gilliam, Adam Cook, Salina Lyter Sep 2012

Effects Of Experimental Freezing On Soil Nitrogen Dynamics In Soils From A Net Nitrification Gradient In A Nitrogen-Saturated Hardwood Forest Ecosystem, Frank S. Gilliam, Adam Cook, Salina Lyter

Frank S. Gilliam

This study examined effects of soil freezing on N dynamics in soil along an N processing gradient within a mixed hardwood dominated watershed at Fernow Experimental Forest, West Virginia. Sites were designated as LN (low rates of N processing), ML (moderately low), MH (moderately high), and HN (high). Soils underwent three 7-day freezing treatments (0, –20, or –80 °C) in the laboratory. Responses varied between temperature treatments and along the gradient. Initial effects differed among freezing treatments for net N mineralization, but not nitrification, in soils across the gradient, generally maintained at LN < ML ≤ MH < HN for all treatments. …


Vegetation And Soil Fertility Changes With Forest Succession In Northern Lower Michigan, Mark Roberts, Frank Gilliam Sep 2012

Vegetation And Soil Fertility Changes With Forest Succession In Northern Lower Michigan, Mark Roberts, Frank Gilliam

Frank S. Gilliam

No abstract provided.


Effects Of Nitrogen On Temporal And Spatial Patterns Of Nitrate In Streams And Soil Solution Of A Central Hardwood Forest, Frank S. Gilliam, Mary Beth Adams Sep 2012

Effects Of Nitrogen On Temporal And Spatial Patterns Of Nitrate In Streams And Soil Solution Of A Central Hardwood Forest, Frank S. Gilliam, Mary Beth Adams

Frank S. Gilliam

This study examined changes in stream and soil water NO3−and their relationship to temporal and spatial patterns of NO3−in soil solution of watersheds at the Fernow Experimental Forest, West Virginia. Following tenfold increases in stream NO3−concentrations over a 13-year period (1969–1981) on untreated WS4, concentrations have declined through 2006. Followingfourfold increases in stream NO3−on treatment WS3 from pretreatment levels to a 1998 maximum, concentrations have declinedthrough 2006, despite additions of N. Concentrations of soil water NO3−were consistently lower for WS4 compared to WS3.Data for soil water NO3−on WS3 versus WS4 followed patterns of net mineralization and nitrification for these watersheds.Nitrogen …


Soil Chemical Response To Experimental Acidification Treatments, Mary Beth Adams, David R. Dewalle, William T. Peterjohn, Frank S. Gilliam, William E. Sharpe, Karl W.J. Williard Sep 2012

Soil Chemical Response To Experimental Acidification Treatments, Mary Beth Adams, David R. Dewalle, William T. Peterjohn, Frank S. Gilliam, William E. Sharpe, Karl W.J. Williard

Frank S. Gilliam

One of the conclusions reached during the Congressionally mandated National Acid Precipitation Program (NAPAP) was that, compared to ozone and other stress factors, the direct effects of acidic deposition on forest health and productivity were likely to be relatively minor. However, the report also concluded “the possibility of long-term (several decades) adverse effects on some soils appears realistic” (Barnard et al. 1990). Possible mechanisms for these long-term effects include: (1) accelerated leaching of base cations from soils and foliage, (2) increased mobilization of aluminum (Al) and other metals such as manganese (Mn), (3) inhibition of soil biological processes, including organic …


Effects Of Experimental Nitrogen Additions On Plant Diversity In Tropical Forests Of Contrasting Disturbance Regimes In Southern China, Xiankai Lu, Jiangming Mo, Frank S. Gilliam, Guirui Yu, Wei Zhang, Yunting Fang, Juan Huang Sep 2012

Effects Of Experimental Nitrogen Additions On Plant Diversity In Tropical Forests Of Contrasting Disturbance Regimes In Southern China, Xiankai Lu, Jiangming Mo, Frank S. Gilliam, Guirui Yu, Wei Zhang, Yunting Fang, Juan Huang

Frank S. Gilliam

Responses of understory plant diversity to nitrogen (N) additions were investigated in reforested forests of contrasting disturbance regimes in southern China from 2003 to 2008: disturbed forest (withharvesting of understory vegetation and litter) and rehabilitated forest (without harvesting). Experimental additions of N were administered as the following treatments: Control, 50 kg N ha1yr1, and 100kg N ha1yr1. Nitrogen additions did not significantly affect understory plant richness, density,and cover in the disturbed forest. Similarly, no significant response was found for canopy closure in thisforest. In the rehabilitated forest, species richness and density showed no significant response to Nadditions; however, understory cover …


Natural Disturbances And The Physiognomy Of Pine Savannas : A Phenomenological Model, Frank S. Gilliam, William J. Platt, Robert K. Peet Sep 2012

Natural Disturbances And The Physiognomy Of Pine Savannas : A Phenomenological Model, Frank S. Gilliam, William J. Platt, Robert K. Peet

Frank S. Gilliam

Abstract. Question: The decline of the Pinus palustris ecosystems has resulted from anthropogenic influences, such as conversion to pine plantation forestry, agriculture and land development, all of which are closely related to increases in human populations. Other effects, however, have arisen from alterations in disturbance regimes that maintain the structure and function of these ecosystems. How have alterations of the disturbance regime altered the physiognomy of ‘old-growth’ stands, and what are the implications for ecosystem conservation and restoration? Methods: In contrast to models that emphasize close interactions among the vertically complex strata, we develop a conceptual phenomenological model for the …


Global Assessment Of Nitrogen Deposition Effects On Terrestrial Plant Diversity : A Synthesis, R. Bobbink, K. Hicks, J. Galloway, T. Spranger, R. Alkemade, M. Ashmore, M. Bustamante, S. Cinderby, E. Davidson, F. Dentener, B. Emmett, J. W. Erisman, M. Fenn, Frank S. Gilliam, A. Nordin, L. Pardo, W. Devries Sep 2012

Global Assessment Of Nitrogen Deposition Effects On Terrestrial Plant Diversity : A Synthesis, R. Bobbink, K. Hicks, J. Galloway, T. Spranger, R. Alkemade, M. Ashmore, M. Bustamante, S. Cinderby, E. Davidson, F. Dentener, B. Emmett, J. W. Erisman, M. Fenn, Frank S. Gilliam, A. Nordin, L. Pardo, W. Devries

Frank S. Gilliam

Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to tropical forests. Current thinking on the mechanisms of N deposition effects on plant diversity, the global distribution of G200 ecoregions, and current and future (2030) estimates of atmospheric N-deposition rates are then used to identify the risks to plant diversity in all major ecosystem types now …


Effects Of Silvicultural Practices On Soil Carbon And Nitrogen In A Nitrogen Saturated Central Appalachian (Usa) Hardwood Forest Ecosystem, Frank S. Gilliam, David A. Dick, Michelle L. Kerr, Mary Beth Adams Sep 2012

Effects Of Silvicultural Practices On Soil Carbon And Nitrogen In A Nitrogen Saturated Central Appalachian (Usa) Hardwood Forest Ecosystem, Frank S. Gilliam, David A. Dick, Michelle L. Kerr, Mary Beth Adams

Frank S. Gilliam

Silvicultural treatments represent disturbances to forest ecosystems often resulting in transient increases in net nitrification and leaching of nitrate and base cations from the soil. Response of soil carbon (C) is more complex, decreasing from enhanced soil respiration and increasing from enhanced postharvest inputs of detritus. Because nitrogen (N) saturation can have similar effects on cation mobility, timber harvesting in N-saturated forests may contribute to a decline in both soil C and base cation fertility, decreasing tree growth. Although studies have addressed effects of either forest harvesting or N saturation separately, few data exist on their combined effects. Our study …


Eastern Temperate Forests, Frank S. Gilliam, Christine L. Goodale, Linda H. Pardo, Linda H. Geiser, Erik A. Lilleskov Sep 2012

Eastern Temperate Forests, Frank S. Gilliam, Christine L. Goodale, Linda H. Pardo, Linda H. Geiser, Erik A. Lilleskov

Frank S. Gilliam

Human activity in the last century has led to a substantial increase in nitrogen (N) emissions and deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the level of pollution that would be harmful to ecosystems is the critical loads approach. The critical load is dei ned as the level of a pollutant below which no detrimental ecological effect occurs over the long term according to present knowledge. The objective of this project was to synthesize …


Response Of The Herbaceous Layer Of Forest Ecosystems To Excess Nitrogen Deposition, Frank Gilliam Sep 2012

Response Of The Herbaceous Layer Of Forest Ecosystems To Excess Nitrogen Deposition, Frank Gilliam

Frank S. Gilliam

  • 1 This review brings into focus what is known about the response of the herbaceous layer of forest ecosystems to increasing nitrogen deposition. The emphasis on forests in general is important for two reasons. First, forests often occupy areas receiving high rates of atmospheric deposition of N. Second, compared with herb-dominated communities, about which much is known regarding response to excess N, forests generally display greater biological and structural complexity. The more specific focus on the herbaceous layer – here defined as all vascular (herbaceous and woody) plants ≤ 1 m in height – is warranted because most of the …


Factors Influencing Spatial Variability In Nitrogen Processing In Nitrogen-Saturated Soils, Frank S. Gilliam, Charles C. Somerville, Nikki L. Lyttle, Mary Beth Adams Sep 2012

Factors Influencing Spatial Variability In Nitrogen Processing In Nitrogen-Saturated Soils, Frank S. Gilliam, Charles C. Somerville, Nikki L. Lyttle, Mary Beth Adams

Frank S. Gilliam

Nitrogen (N) saturation is an environmental concern for forests in the eastern U.S. Although several watersheds of the Fernow Experimental Forest (FEF), West Virginia exhibit symptoms of Nsaturation, many watersheds display a high degree of spatial variability in soil N processing. This study examined the effects of temperature on net N mineralization and nitrification in N-saturatedsoils from FEF, and how these effects varied between high N-processing vs. low N-processingsoils collected from two watersheds, WS3 (fertilized with [NH4]2SO4) and WS4 (untreated control). Samples of forest floor material (O2 horizon) and mineral soil (to a 5-cm depth) were taken from three subplots …


Acidification And Nutrient Cycling, Mary Beth Adams, William T. Peterjohn, Frank S. Gilliam Sep 2012

Acidification And Nutrient Cycling, Mary Beth Adams, William T. Peterjohn, Frank S. Gilliam

Frank S. Gilliam

Additions of acid anions can alter the cycling of other nutrients and elements within an ecosystem. As strong acid ions move through a forest, they may increase the concentrations of nitrogen (N) and sulfur (S) in the soil solution and stream water. Such treatments also may increase or decrease the availability of other anions, cations and metal ions in the soil. A number of studies in Europe and North America have documented increases in base cation concentrations such as calcium (Ca) and magnesium (Mg) with increased N and S deposition (Foster and Nicolson 1988, Feger 1992, Norton et al. 1994, …


Conservation And Restoration Of The Pinus Palustris Ecosystem, Frank S. Gilliam, William J. Platt Sep 2012

Conservation And Restoration Of The Pinus Palustris Ecosystem, Frank S. Gilliam, William J. Platt

Frank S. Gilliam

The well-documented decline of the Pinus palustris ecosystem has resulted from several anthropogenic influences, such as forest clearing (e.g. pine plantation forestry, agriculture) and urban development, both of which are closely related to increases in human populations. Other impacts have arisen from alterations in disturbance regimes responsible for maintaining the structure and function of these ecosystems. Restoration and management of degraded pine savanna ecosystems is critical. Identification of ecological processes that determine the structure and function of the intact system are important because successful restoration efforts should be based on sound scientific understanding. In this paper, we introduce this special …


Interspecific Divergence In Foliar Nutrient Dynamics And Stem Growth In A Temperate Forest In Response To Chronic Nitrogen Inputs, Jeffrey May, Sarah Burdette, Frank Gilliam, Mary Adams Sep 2012

Interspecific Divergence In Foliar Nutrient Dynamics And Stem Growth In A Temperate Forest In Response To Chronic Nitrogen Inputs, Jeffrey May, Sarah Burdette, Frank Gilliam, Mary Adams

Frank S. Gilliam

We studied the effects of excessive nitrogen (N) fertilization on foliar nutrient dynamics and stem growth in three important tree species in a mixed-deciduous forest. Stem diameter growth, foliar N concentrations, nitrogen–phosphorus (N/P) ratios, and nutrient resorption were determined for Acer rubrum L. (ACRU), Liriodendron tulipifera L. (LITU), and Prunus serotina Ehrh. (PRSE) on two 30-year-old watersheds at the Fernow Experimental Forest, West Virginia, USA: WS3, fertilized annually with 35 kg ammonium sulfate ha–1 since 1989, and WS7, an untreated control watershed. In an earlier (1992) study, foliar N concentrations of all three species averaged 11% higher in WS3 than …


Effects Of Experimental Nitrogen Additions On Plant Diversity In An Old-Growth Tropical Forest, Xiankai Lu, Jiangming Mo, Frank S. Gilliam, Guoyi Zhou, Yunting Fang Sep 2012

Effects Of Experimental Nitrogen Additions On Plant Diversity In An Old-Growth Tropical Forest, Xiankai Lu, Jiangming Mo, Frank S. Gilliam, Guoyi Zhou, Yunting Fang

Frank S. Gilliam

Response of plant biodiversity to increased availability of nitrogen (N) has been investigated in temperate and boreal forests, which are typically N-limited, but little is known in tropical forests. We examined the effects of artificial N additions on plant diversity (species richness, density and cover) of the understory layer in an N saturated old-growth tropical forest in southern China to test the following hypothesis: N additions decrease plant diversity in N saturated tropical forests primarily from N-mediated changes in soil properties. Experimental additions of N were administered at the following levels from July 2003 to July 2008: no addition (Control); …


Forest Vegetation Of The Routt National Forest In Northwestern Colorado: A Habitat Type Classification, George R. Hoffman, Robert R. Alexander Sep 2012

Forest Vegetation Of The Routt National Forest In Northwestern Colorado: A Habitat Type Classification, George R. Hoffman, Robert R. Alexander

Robert P Alexander

No abstract provided.


Range Liverstock Nutrition And Its Importance In The Intermountain Region, C. Wayne Cook Aug 2012

Range Liverstock Nutrition And Its Importance In The Intermountain Region, C. Wayne Cook

Christopher Cook

It has been estimated that about 728 million acres or about 76 percent of the entire land area in the West is used for grazing (Stoddard and Smith 1956). In Utah about 93 percent of the land area or 48,900,000 acres is considered range land (Reuss and Blanch 1951). Although some of this range land is forested, a large area of it can be used only for grazing. Therefore, range livestock production is an important segment of western agriculture.

Before 19'00 most of the animals in the West grazed on the range all year. However, irrigation crop production has expanded …


Rust And Beetle Interactions In Pinus Albicaulis Ecosystems, Nancy Bockino, Daniel B. Tinker Jun 2012

Rust And Beetle Interactions In Pinus Albicaulis Ecosystems, Nancy Bockino, Daniel B. Tinker

Daniel B Tinker

Current mountain pine beetle activity in whitebark pine ecosystems in the Greater Yellowstone Ecosystem is unprecedented in extent and severity. Dynamics among beetles, white pine blister rust, and climate change are placing this foundation species in a precarious state. Stand- and tree-level data was recorded to quantify how the severity of rust and the presence of an alternate host influence the susceptibility of whitebark to selection by the beetle. Data reveal that 52% of whitebark sampled were dead, 70% attacked by the beetle, 85% infected with rust, and 61% were afflicted with both. Beetle activity was lower than expected in …


Genetic Diversity And Structure Of The Fisher (Martes Pennanti) In A Peninsular And Peripheral Metapopulation, Samantha M. Wisely, Steven W. Buskirk, Gregory A. Russell, Keith B. Aubry, William J. Zielinsky Jun 2012

Genetic Diversity And Structure Of The Fisher (Martes Pennanti) In A Peninsular And Peripheral Metapopulation, Samantha M. Wisely, Steven W. Buskirk, Gregory A. Russell, Keith B. Aubry, William J. Zielinsky

Steven Buskirk

Evolutionary processes can be strongly affected by landscape features. In vagile carnivores that disperse widely, however, genetic structure has been found to be minimal. Using microsatellite DNA primers developed for other mustelids, we found that populations of a vagile forest carnivore, the fisher (Martes pennanti), exhibit high genetic structure (FST = 0.45, SE = 0.07) and limited gene flow (Nm < 1) within a .1,600-km narrow strip of forested habitat; that genetic diversity decreases from core to periphery; and that populations do not show an equilibrium pattern of isolation-by-distance. Genetic structure was greater at the periphery than at the core of …


Dynamics Of Land Use/Land Cover Changes And Its Implication On Food Security In Anyigba, North Central, Nigeria, Tokula E. Arome, Sunday P. Ejaro (Phd) May 2012

Dynamics Of Land Use/Land Cover Changes And Its Implication On Food Security In Anyigba, North Central, Nigeria, Tokula E. Arome, Sunday P. Ejaro (Phd)

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

This study assessed land use/land cover changes and its effect on Agricultural land in Anyigba. The objectives were to identify and delineate different land use / land cover categories, assess the rate of change that occurred and examine the impact of land use/land cover change on food security using satellite remote sensing data collected at three different years (1987 Land sat TM, 2001 Land Sat TM and 2011 Land Sat ETM). The study utilized GIS software such as Idrisi Andes academic and ArcGIS 9.3. The study area covers approximately 31.8km2, and four major land use/cover classes were utilized (built up, …


Phylogenetics Of Morus (Moraceae) Inferred From Its And Trnl-Trnf Sequence Data., Madhav Nepal Mar 2012

Phylogenetics Of Morus (Moraceae) Inferred From Its And Trnl-Trnf Sequence Data., Madhav Nepal

Madhav Nepal

Morus (Tribe Moreae, Moraceae) consists of ca. 13 species of trees distributed in Asia, Africa, Europe, and North, Central, and South America. The broad geographical distribution of the genus, overlapping ranges of many taxa, and documented hybridization between some species present interesting questions of taxonomy, phylogeny, and biogeography. Phylogenetic data for Morus also contribute to higher level taxonomic work in the family. We used sequence data from ITS of the nrDNA and the chloroplast trnL-trnF intergenic spacer to study phylogenetic relationships of Morus. Phylogenies based on separate data sets were not statistically incongruent, and the combined tree …