scholarly journals What is driving declines of montane endemic amphibians? New insights from Mount Bamboutos, Cameroon

Oryx ◽  
2019 ◽  
pp. 1-11 ◽  
Author(s):  
A. M. Tchassem F. ◽  
T. M. Doherty-Bone ◽  
M. M. Kameni N. ◽  
W. P. Tapondjou N. ◽  
J. L. Tamesse ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Historical Records ◽  
Land Use Patterns ◽  
Forest Patches ◽  
Amphibian Species ◽  
Use Patterns ◽  
Amphibian Community ◽  
Frog Species ◽  
Forested Areas

Abstract Amphibians on African mountains are threatened by habitat loss and fragmentation, pollution, disease and climate change. In particular, there have been recent reports of declines of montane endemic frogs in Cameroon. Mount Bamboutos, although home to numerous species of endemic amphibians, has no official protection and its amphibian populations have so far not been studied quantitatively. We surveyed frog assemblages on this mountain along a gradient of forest modification over a 2-year period. Through visual encounter surveys stratified across forest and farmland, we found that threatened montane amphibian species are closely associated with forested areas, particularly the Critically Endangered Leptodactylodon axillaris and Endangered Leptodactylodon perreti, Astylosternus ranoides and Cardioglossa oreas. Using the updated inventory of amphibians, which includes species with broader ranges across Africa, we found 69% of amphibian species on Mount Bamboutos to be threatened. We did not record several species present in historical records, which suggests they may have disappeared from this mountain, including Cardioglossa pulchra, Phrynobatrachus steindachneri, Phrynobatrachus werneri, Sclerophrys villiersi, Werneria bambutensis and Wolterstorffina mirei. The pattern of change detected in the amphibian community is consistent with declines on other mountains in the country, with a loss of Phrynobatrachus, Werneria and Cardioglossa spp., but persistence of Astylosternus, Arthroleptis and Leptodacty-lodon. The observed relationships of land-use patterns and amphibian diversity suggest that ongoing land-use changes could extirpate the remaining montane endemic frog species, particularly L. axillaris and L. perreti. Preserving a network of connected forest patches is therefore critical to save the endemic amphibians of Mount Bamboutos.

Generating Policies for Sustainable Water Use in Complex Scenarios: An Integrated Land-Use and Water-Use Model of Monroe County, Michigan

2007 ◽  
Vol 34 (4) ◽  
pp. 664-686 ◽  
Author(s):  
Moira L Zellner
Keyword(s):  
Land Use ◽  
Water Use ◽  
Land Use Changes ◽  
Resource Depletion ◽  
Analytical Framework ◽  
Monroe County ◽  
Land Use Patterns ◽  
Groundwater Levels ◽  
Use Patterns ◽  
Water Users

Rapidly declining groundwater levels since the early 1990s have raised serious concern in Monroe County, Michigan. Hydrological studies suggest that land-use changes have caused this decline. The mechanisms linking land-use and groundwater dynamics are not clear, however. In this paper I present WULUM, the Water-Use and Land-Use Model, an agent-based model that serves as an analytical framework to understand how these processes interact to create the observed patterns of resource depletion, and to suggest policies to reverse the process. The land-use component includes the main groundwater extractors in the county—stone quarries, golf courses, farms, and households. The groundwater component includes the glacial deposits and the underlying bedrock acquifer. The behavior of water users is defined by simple rules that determine their location and consumption. The dynamics of groundwater are represented through infiltration and diffusion rules between each cell and its immediate neighbors. Initial explorations with the model showed that land-use patterns contributed significantly to groundwater declines, while eliminating quarry dewatering did not entirely solve the problem. Both low-density and high-density zoning restrictions improved aquifer conditions over medium-density development, suggesting a nonlinear relationship between intensity of residential use and groundwater levels. Moreover, of all the natural and policy variables, zoning had the greatest influence on urban settlement and therefore on resource consumption.

Environmental carrying capacity for sustainable shrimp farming.

2020 ◽  
Author(s):  
Md. Zakir Hossain ◽  
Nitin K. Tripathi ◽  
Michael J. Phillips
Keyword(s):  
Land Use ◽  
Carrying Capacity ◽  
Geographical Information Systems ◽  
Negative Impact ◽  
Land Use Changes ◽  
Shrimp Farming ◽  
Geographical Information ◽  
Land Use Patterns ◽  
Use Patterns ◽  
Creek Water

Abstract Aquaculture, particularly shrimp farming in the Kandaleru creek area, has shown spectacular growth within the last two decades. However, economic prosperity which was the driving force for shrimp farming expansion, has also had a significant negative impact on land use changes and creek water quality causing shrimp health hazards. Using a hypothesis that the discharge of shrimp farming effluents may have exceeded the carrying capacity (CC) of the creek water, the environmental CC of Kandaleru creek was assessed based on total nitrogen (TN) input. Remote sensing (RS) and image enhancement techniques integrated with geographical information systems (GIS) were applied to quantify and determine the changes in land use patterns in the creek area. GIS and a numeric model were used to compute the TN load in three different salinity zones to determine the CC status. The study revealed that exceeding the CC of the creek along with increasing shrimp farms, decreasing natural resources and changes in land use patterns.

scholarly journals Simulation and Analysis of Land Use Changes Applying Cellular Automata in the South of Quito and the Machachi Valley, Province of Pichincha, Ecuador

2021 ◽  
Vol 13 (17) ◽  
pp. 9525
Author(s):  
René Ulloa-Espíndola ◽  
Susana Martín-Fernández
Keyword(s):  
Land Use ◽  
Cellular Automata ◽  
Urban Areas ◽  
Land Use Changes ◽  
Urban Land Use ◽  
The South ◽  
Land Use Patterns ◽  
Use Patterns ◽  
Urban Settlements ◽  
The City

Rapid urban growth has historically led to changes in land use patterns and the degradation of natural resources and the urban environment. Uncontrolled growth of urban areas in the city of Quito has continued to the present day since 1960s, aggravated by illegal or irregular new settlements. The main objective of this paper is to generate spatial predictions of these types of urban settlements and land use changes in 2023, 2028 and 2038, applying the Dinamica EGO cellular automata and multivariable software. The study area was the Machachi Valley between the south of the city of Quito and the rural localities of Alóag and Machachi. The results demonstrate the accuracy of the model and its applicability, thanks to the use of 15 social, physical and climate predictors and the validation process. The analysis of the land use changes throughout the study area shows that urban land use will undergo the greatest net increase. Growth in the south of Quito is predicted to increase by as much as 35% between 2018 and 2038 where new highly vulnerable urban settlements can appear. Native forests in the Andes and forest plantations are expected to decline in the study area due to their substitution by shrub vegetation or agriculture and livestock land use. The implementation of policies to control the land market and protect natural areas could help to mitigate the continuous deterioration of urban and forest areas.

Land-Use Changes in Owens Valley Prehistory: A Matter of Statistical Inference

1981 ◽  
Vol 46 (3) ◽  
pp. 648-656 ◽  
Author(s):  
M. C. Hall
Keyword(s):  
Land Use ◽  
Land Use Changes ◽  
Potential Effect ◽  
Spatial And Temporal Variation ◽  
Published Data ◽  
Owens Valley ◽  
Land Use Patterns ◽  
Use Patterns ◽  
Adaptive Shifts ◽  
Considerable Support

In a recent exchange Munday and Lincoln (1979) and Bettinger (1979a) debate the conclusions reached by Bettinger (1977) regarding diachronic variation in the prehistoric land-use patterns of Owens Valley, California. There are several related sources of error in Bettinger's quantitative and statistical operations that were not clarified or discussed in the published arguments. An evaluation of their potential effect on the analysis conducted by Bettinger (1975) lends considerable support to the basic assertion of Munday and Lincoln that Bettinger (1977) did not fully appreciate alternative explanations of the spatial and temporal variation he observed in site and artifact distributions in Owens Valley. Two of the three "adaptive shifts" in land-use patterns proposed by Bettinger are not supported by the published data.

scholarly journals Changing Land Use Patterns and Their Impacts on Wild Ungulates in Kimana Wetland Ecosystem, Kenya

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Stephen Kitina Nyamasyo ◽  
Bonface Odiara Kihima
Keyword(s):  
Land Use ◽  
Land Tenure ◽  
Land Use Changes ◽  
Remote Sensing Data ◽  
Habitat Destruction ◽  
Benefit Sharing ◽  
Sociocultural Factors ◽  
Wild Ungulates ◽  
Land Use Patterns ◽  
Use Patterns

In Kenya, wildlife numbers have drastically declined due to land use changes (LUCs) over the past three decades. This has affected wildlife habitats by converting them into farmlands and human settlements. This study used remote sensing data from landsat satellite to analyze the changing land use patterns between 1980 and 2013 and their impacts on wild ungulates in KWE. The objective of the study was to map out LUCs, determine the possible causes of LUCs, and examine the effects of LUCs on wild ungulates. The results showed a noticeable increase in the size of farmland, settlement, and other lands and a decline in forestland, grassland, wetland, and woodland. The main possible causes of LUC were found to be agricultural expansions, human population dynamics, economic factors, changing land tenure policy, politics, and sociocultural factors. The main effects of LUCs on wild ungulates in KWE include a decline in wild ungulate numbers, habitat destruction, increased human-wildlife conflicts, land degradation, and displacement of wild ungulates by livestock. The study recommends land use zoning of KWE and establishment of an effective and efficient wildlife benefit-sharing scheme(s).

scholarly journals Dynamic Simulation of Land Use Change of the Upper and Middle Streams of the Luan River, Northern China

2019 ◽  
Vol 11 (18) ◽  
pp. 4909 ◽  
Author(s):  
Xia Xu ◽  
Mengxi Guan ◽  
Honglei Jiang ◽  
Lingfei Wang
Keyword(s):  
Land Use ◽  
River Basin ◽  
Land Use Planning ◽  
Land Use Changes ◽  
Northern China ◽  
Transitional Zone ◽  
Sustainable Land Use ◽  
Land Use Patterns ◽  
Reference Case ◽  
Use Patterns

Climatic, socio-economic, geophysical, and human activity factors, among others, influence land use patterns. However, these driving factors also have different relationships with each other. Combining machine learning methods and statistical models is a good way to simulate the dominant land use types. The Luan River basin is located in a farming-pastoral transitional zone and is an important ecological barrier between Beijing and Tianjin. In this study, we predicted future land use and land cover changes from 2010 to 2020 in the Luan River’s upper and middle reaches under three scenarios—the natural scenario, the ecological scenario, and the sustainable scenario. The results indicate that cultivated land will decrease while the forested areas will increase quantitatively in the future. Built-up areas would increase quickly in the natural scenario, and augmented expansion of forest would be the main features of land use changes in both the ecological scenario and the sustainable scenario. Regarding the spatial pattern, different land use patterns will be aggregated and patches will become larger. Our findings for the scenario analysis of land use changes can provide a reference case for sustainable land use planning and management in the upper and middle Luan River basin.

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