scholarly journals Impact of land use on juvenile densities of woody plants in a West African savanna

2016 ◽  
Vol 19 ◽  
pp. 18-34
Author(s):  
Katrin Jurisch ◽  
Markus Bernhardt-Römermann ◽  
Rüdiger Wittig ◽  
Karen Hahn
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Soil Properties ◽  
Vegetation Structure ◽  
Environmental Parameters ◽  
Woody Species ◽  
West African ◽  
Initial Growth ◽  
Land Cover Types ◽  
Human Land Use

In West African savannas, human land use affects the density of woody species seedlings and saplings (juveniles) by altering the state of the physical, chemical, and biological characteristics of the land resulting in different land-cover types. We determined juvenile densities of 25 characteristic woody savanna species on non-arable sites, in fallows and in a protected area (in total 39 plots), and analyzed the influence of land use on juvenile densities. We further related the influence of land use on juvenile densities to 23 environmental parameters describing soil properties and vegetation structure. Soil acidity, particle size distribution of the soil, and vegetation structure differed between land-cover types. In terms of human impact, we detected five groups of species responding similarly to land use. Although we detected significant differences in soil properties, their direct effects on juvenile densities are less pronounced than their indirect effects. By altering the availability of resources, soil properties affect height and cover of all plants growing in the surrounding of a young woody plant, increasing the competition for light, water and nutrients during the establishment and initial growth. These effects are intensified by human land use and vary between land-cover types.

REMOTE-SENSING EXPERT CLASSIFICATION OF LAND USE/LAND COVER TYPES USING FRACTAL DIMENSIONS OVER A SUBTROPICAL HILLY REGION IN CHINA

Fractals ◽  
2011 ◽  
Vol 19 (04) ◽  
pp. 407-421
Author(s):  
JI ZHU ◽  
ZIYU LIN ◽  
XIAOZHOU LI
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Fractal Dimension ◽  
Land Cover ◽  
Fractal Dimensions ◽  
Land Use Land Cover ◽  
Surface Features ◽  
Land Cover Types ◽  
Hilly Region ◽  
Expert Classification

In the work, a simple and reliable algorithm is presented to calculate the fractal dimension of single pixel for the remote sensing images, and the fractal dimension values obtained by the algorithm proposed in this work have positive correlation with the complexity of surface features. On the basis of a scene of Landsat7 ETM+ (i.e., Enhanced Thematic Mapper Plus) data and the proposed algorithm, expert classification models and fractal technique were introduced to identify the ground objects in a Chinese subtropical hilly region, where surface features are very diverse and complex. In the work, the different land use/land cover types, especially the different vegetation categories were successfully identified using the ETM+ image, and this classification has an overall accuracy of 80.25% and a K hat of 0.7738, which are higher than those of the traditional supervised classification.

scholarly journals Continuous and consistent land use/cover change estimates using socio-ecological data

2016 ◽  
Author(s):  
Michael Marshall ◽  
Michael Norton-Griffiths ◽  
Harvey Herr ◽  
Richard Lamprey ◽  
Justin Sheffield ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Land Surface ◽  
Natural Vegetation ◽  
Additive Models ◽  
Sub Saharan Africa ◽  
Land Cover Types ◽  
Remote Sensing Classification ◽  
Functional Relationships ◽  
Macro Scale

Abstract. A growing body of research shows the importance of land use/cover change (LULCC) on modifying the earth system. Land surface models are used to stimulate land-atmosphere dynamics at the macro- (regional to global) scale, but bias and uncertainty remain that need to be addressed, before the importance of LULCC is fully realized. In this study, we propose a method of improving LULCC estimates for land surface modelling exercises. The method yields continuous (annual) long-term (30-year) estimates of LULCC driven by socio-ecological geospatial predictors available seamlessly across sub-Saharan Africa that can be used for both retrospective and prospective analyses. The method was developed with 2252 5 × 5 km2 sample frames of the proportion of several land cover types in Kenya over multiple years. Forty-three socio-ecological predictors were evaluated for model development. Machine learning was used for data reduction and simple (functional) relationships defined by generalized additive models were constructed on a subset of the highest ranked predictors (p ≤ 10) to estimate LULCC. The predictors explained 62 % and 65 % of the variance in the proportion of agriculture and natural vegetation, respectively, but were less successful at estimating more descriptive land cover types. In each case, population density on an annual basis was the highest ranked predictor. The approach was compared to a commonly used remote sensing classification procedure, given the wide use of such techniques for macro-scale LULCC detection, and out-performed it for each land cover type. The approach was used to demonstrate significant trends in expanding (declining) agricultural (natural vegetation) land cover in Kenya from 1983–2012, with the largest increases (declines) occurring in densely populated high agricultural production zones.

Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages

2019 ◽  
Keyword(s):  
United States ◽  
Land Use ◽  
Land Cover ◽  
Biological Properties ◽  
Western United States ◽  
Stream Ecosystems ◽  
Human Land Use ◽  
Natural Land ◽  
Stream Biota ◽  
Land Use And Cover

<i>Abstract.</i>—Surrounding land use and cover can have profound effects on the physical, chemical, and biological properties of stream ecosystems. For this reason, changes in land use and cover throughout catchments often have strong effects on stream ecosystems that are particularly interesting to researchers. Additionally, natural physical and climatic, or physiographic, characteristics are important for determining natural land cover and constraining human land use and are also strongly related to stream habitat and biota. Because the physiographic template differs among catchments and is an important mediator of catchment processes, it is important to account for natural physiographic differences among catchments to understand the relationship between land use/cover and stream biota. In this paper, we develop and assess the usefulness of a regional framework, land use/cover distinguished physiographic regions (LDPRs), which is designed for understanding relationships between land use/cover and stream biota while accounting for the physiographic template. We classified hydrologic units into LDPRs based on physiographic predictors of land use and cover for the eastern and western United States through the use of multivariate regression tree analysis. Next, we used case study data to assess the usefulness of LDPRs by determining if the relationships between fish assemblage function and land use/cover varied among classes using hierarchical logistic regression models. Eight physiographic characteristics determined land cover patterns for both the eastern and western United States and were used to classify hydrologic units into LDPR classes. Five commonly used biotic metrics describing trophic, reproductive, and taxonomic groupings of fish species responded in varying ways to agriculture and urban land use across LDPRs in the upper Mississippi River basin. Our findings suggest that physiographic differences among hydrologic units result in different pathways by which land use and cover affects stream fish assemblages and that LDPRs are useful for stratifying hydrologic units to investigate those different processes. Unlike other commonly used regional frameworks, the rationale and methods used to develop LDPRs properly account for the often-confounded relationship between physiography and land use/cover when relating land cover to stream biota. Therefore, we recommend the use and refinement of LDPRs or similarly developed regional frameworks so that the varying processes by which human land use results in stream degradation can be better understood.

Total carbon and nitrogen stocks under different land use/land cover types in the Southwestern region of Nigeria

2020 ◽  
Vol 22 ◽  
pp. e00320
Author(s):  
Idowu Ezekiel Olorunfemi ◽  
Johnson Toyin Fasinmirin ◽  
Ayorinde Akinlabi Olufayo ◽  
Akinola Adesuji Komolafe
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Total Carbon ◽  
Land Use Land Cover ◽  
Land Cover Types ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Stocks

scholarly journals Effects of Land Use/Land Cover Changes on Selected Soil Physical and Chemical Properties in Shenkolla Watershed, South Central Ethiopia

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Belayneh Bufebo ◽  
Eyasu Elias
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Soil Fertility ◽  
Soil Properties ◽  
Land Cover Changes ◽  
Land Use Land Cover ◽  
Forest Land ◽  
South Central ◽  
Effects Of Land Use ◽  
Poor Management

Land use change from natural ecosystems to managed agroecosystems is one of the main causes of soil fertility decline. Severe soil erosion caused by agricultural expansion and poor management worsened soil nutrient depletion in cultivated outfields (crop lands). This study was conducted to examine the effects of land use and land cover changes (LU/LC) on selected soil physicochemical properties in the Shenkolla watershed. A total of 40 top soil samples at 0–20 cm depth were collected from four land use/land cover types (forest land, grazing land, cultivated outfield, and cultivated homestead garden fields). The analysis of variance (ANOVA) was applied to determine differences in soil parameters among land use types. Treatment means comparison was determined using the least significant difference (LSD) at 0.05 level of significances. The result indicated that there were significant P<0.05 differences among the four LU/LC types for soil characteristics. For most parameters evaluated, the most favorable soil properties were observed in the forest land, followed by homestead garden fields, while the least favorable soil properties were found in intensively cultivated outfields. Increase in the extent of cultivated land at the expense of forest cover associated with poor management has promoted significant loss of soil quality in intensively cultivated outfields. Reducing the land cover conversion and adopting proper management practices of the soil commonly used in homestead garden fields are very crucial in order to improve soil fertility in intensively cultivated outfields.

scholarly journals Environmental Differences between Migratory and Resident Ungulates—Predicting Movement Strategies in Rocky Mountain Mule Deer (Odocoileus hemionus) with Remotely Sensed Plant Phenology, Snow, and Land Cover

2019 ◽  
Vol 11 (17) ◽  
pp. 1980
Author(s):  
Benjamin Robb ◽  
Qiongyu Huang ◽  
Joseph Sexton ◽  
David Stoner ◽  
Peter Leimgruber
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Snow Cover ◽  
Large Scale ◽  
Mule Deer ◽  
Life History Strategy ◽  
Odocoileus Hemionus ◽  
Remotely Sensed ◽  
Land Use Impacts ◽  
Human Land Use

Migration is a valuable life history strategy for many species because it enables individuals to exploit spatially and temporally variable resources. Globally, the prevalence of species’ migratory behavior is decreasing as individuals forgo migration to remain resident year-round, an effect hypothesized to result from anthropogenic changes to landscape dynamics. Efforts to conserve and restore migrations require an understanding of the ecological characteristics driving the behavioral tradeoff between migration and residence. We identified migratory and resident behaviors of 42 mule deer (Odocoileus hemionus) based on GPS locations and correlated their locations to remotely sensed indicators of forage quality, land cover, snow cover, and human land use. The model classified mule deer seasonal migratory and resident niches with an overall accuracy of 97.8% and cross-validated accuracy of 81.2%. The distance to development was the most important variable in discriminating in which environments these behaviors occur, with resident niche space most often closer to developed areas than migratory niches. Additionally, snow cover in December was important for discriminating summer migratory niches. This approach demonstrates the utility of niche analysis based on remotely sensed environmental datasets and provides empirical evidence of human land use impacts on large-scale wildlife migrations.

scholarly journals Consistency of wind erosion assessments across land use and land cover types: A critical analysis

2014 ◽  
Vol 15 ◽  
pp. 253-260 ◽  
Author(s):  
Junran Li ◽  
Gregory S. Okin ◽  
John Tatarko ◽  
Nicholas P. Webb ◽  
Jeffrey E. Herrick
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Critical Analysis ◽  
Wind Erosion ◽  
Land Cover Types
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