scholarly journals Landscape Structure of Woody Cover Patches for Endangered Ocelots in Southern Texas

2021 ◽  
Vol 13 (19) ◽  
pp. 4001
Author(s):  
Jason V. Lombardi ◽  
Humberto L. Perotto-Baldivieso ◽  
Maksim Sergeyev ◽  
Amanda M. Veals ◽  
Landon Schofield ◽  
...  
Keyword(s):  
Landscape Structure ◽  
Shape Index ◽  
Patch Area ◽  
Gps Telemetry ◽  
Leopardus Pardalis ◽  
New Approach ◽  
Recovery Strategies ◽  
Road Planning ◽  
Landscape Suitability ◽  
Woody Cover

Few ecological studies have explored landscape suitability using the gradient concept of landscape structure for wildlife species. Identification of conditions influencing the landscape ecology of endangered species allows for development of more robust recovery strategies. Our objectives were to (i) identify the range of landscape metrics (i.e., mean patch area; patch and edge densities; percent land cover; shape, aggregation, and largest patch indices) associated with woody vegetation used by ocelots (Leopardus pardalis), and (ii) quantify the potential distribution of suitable woody cover for ocelots across southern Texas. We used the gradient concept of landscape structure and the theory of slack combined with GPS telemetry data from 10 ocelots. Spatial distribution of high suitable woody cover is comprised of large patches, with low shape-index values (1.07–2.25), patch (27.21–72.50 patches/100 ha), and edge (0–191.50 m/ha) densities. High suitability landscape structure for ocelots occurs in 45.27% of woody cover in southern Texas. Our study demonstrates a new approach for measuring landscape suitability for ocelots in southern Texas. The range of landscape values identified that there are more large woody patches containing the spatial structure used by ocelots than previously suspected, which will aid in evaluating recovery and road planning efforts.

scholarly journals Relevance of the Cell Neighborhood Size in Landscape Metrics Evaluation and Free or Open Source Software Implementations

2019 ◽  
Vol 8 (12) ◽  
pp. 586
Author(s):  
Paolo Zatelli ◽  
Stefano Gobbi ◽  
Clara Tattoni ◽  
Maria Giulia Cantiani ◽  
Nicola La Porta ◽  
...  
Keyword(s):  
Open Source ◽  
Open Source Software ◽  
Landscape Metrics ◽  
Shape Index ◽  
Edge Density ◽  
Patch Area ◽  
Aggregation Index ◽  
Use Values ◽  
Software Implementations ◽  
Patch Density

Landscape metrics constitute one of the main tools for the study of the changes of the landscape and of the ecological structure of a region. The most popular software for landscape metrics evaluation is FRAGSTATS, which is free to use but does not have free or open source software (FOSS). Therefore, FOSS implementations, such as QGIS’s LecoS plugin and GRASS’ r.li modules suite, were developed. While metrics are defined in the same way, the “cell neighborhood” parameter, specifying the configuration of the moving window used for the analysis, is managed differently: FRAGSTATS can use values of 4 or 8 (8 is default), LecoS uses 8 and r.li 4. Tests were performed to evaluate the landscape metrics variability depending on the “cell neighborhood” values: some metrics, such as “edge density” and “landscape shape index”, do not change, other, for example “patch number”, “patch density”, and “mean patch area”, vary up to 100% for real maps and 500% for maps built to highlight this variation. A review of the scientific literature was carried out to check how often the value of the “cell neighborhood” parameter is explicitly declared. A method based on the “aggregation index” is proposed to estimate the effect of the uncertainty on the “cell neighborhood” parameter on landscape metrics for different maps.

scholarly journals Patch metrics of roosting site selection by Lyle’s flying fox (Pteropus lylei Andersen, 1908) in a human-dominated landscape in Thailand

2019 ◽  
Vol 46 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Prateep Duengkae ◽  
Pongsit Srikhunmuang ◽  
Aingorn Chaiyes ◽  
Warong Suksavate ◽  
Nantachai Pongpattananurak ◽  
...  
Keyword(s):  
Potential Distribution ◽  
Shape Index ◽  
Distribution Map ◽  
Negative Effects ◽  
Patch Area ◽  
Patch Shape ◽  
Maximum Entropy Modeling ◽  
External Threats ◽  
Shape Complexity ◽  
Flying Fox

AbstractThe association between patch metrics and roosting site (n = 31) suitability of Lyle’s flying fox (Pteropus lylei) in 26 Central Eastern and Western provinces of Thailand was quantified. Land use classes with 90-m resolution were identified based on various vegetation and land cover types to calculate patch metrics using FRAGSTATS. Then, Maximum Entropy Modeling (MaxEnt) was performed using patch metrics covariates to produce a predictive potential distribution map. The results indicated that patch contiguity (contiguity index, 63.7%), patch area (29.3%), and patch shape complexity (shape index, 5.7%) are the most influential patch metrics, all of which have negative effects on roosting site suitability. In total, 13,222 small patches were considered highly suitable patches, with a mean area of 0.921 ± 0.698 (SD) ha, which accounted for 122,090 ha (2.04%) of the study area. Roosting sites predicted from the model were consistently associated with occurrences of roosting sites observed in temples; such habitats likely provide shelter from external threats for colonies roosting in a human-dominated landscape.

Evaluating recovery strategies for an ocelot (Leopardus pardalis) population in the united states

2005 ◽  
Vol 126 (4) ◽  
pp. 512-522 ◽  
Author(s):  
Aaron M. Haines ◽  
Michael E. Tewes ◽  
Linda L. Laack ◽  
William E. Grant ◽  
John Young
Keyword(s):  
United States ◽  
The United States ◽  
Leopardus Pardalis ◽  
Recovery Strategies

scholarly journals Multi-temporal analysis of an agricultural landscape transformation and abandonment (Lubietová, Central Slovakia)

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Matej Masný ◽  
Lubica Zaušková
Keyword(s):  
Landscape Structure ◽  
Patch Size ◽  
Agricultural Landscape ◽  
Agricultural Land ◽  
Biosphere Reserve ◽  
Temporal Analysis ◽  
Shape Index ◽  
Agricultural Landscapes ◽  
Agricultural Abandonment ◽  
Size Standard

AbstractSocio-political changes in the countries of Eastern and Central Europe in the era of socialism had significant effects on agricultural landscape. Collectivisation (1950 - 1970) lost almost all of traditional agricultural landscapes. On the other hand, the phenomenon of agricultural abandonment started to be significant after 1989. In the model area (part of The Polana Biosphere Reserve) these two processes that formed the agricultural landscape structure were analysed. The analyses were carried out using orthophotos that represented the landscape structure in 1949, 1986 and 2006. It was found that almost complete extinction of the traditional agricultural landscape represented by a mosaic of narrow fields and permanent grasslands occurred during the period. At the same time, increasing trend of abandonment processes was observed. In 2006, non-forestwoody vegetation covered 48% of agricultural land.Natural reforestation as the final stage of agricultural abandonment extended to 46% on the former agricultural land in 2006. Abandonment processes were the most significant already in the period of socialist agriculture. To describe the changes, landscape metrics such as Number of patches (NP), Mean patch size (MPS), Patch size standard deviation (PSSD) and Mean shape index (MSI) were used.

First ocelot (Leopardus pardalis) monitored with GPS telemetry

2006 ◽  
Vol 52 (3) ◽  
pp. 216-218 ◽  
Author(s):  
Aaron M. Haines ◽  
Lon I. Grassman ◽  
Michael E. Tewes ◽  
Jan E. Janečka
Keyword(s):  
Gps Telemetry ◽  
Leopardus Pardalis

scholarly journals Assessment of ecological values of greening landscape elements in the Great Hungarian Plain

2017 ◽  
Vol 10 (3-4) ◽  
pp. 35-41
Author(s):  
Klaudia Máté
Keyword(s):  
Landscape Structure ◽  
Shape Index ◽  
Research Field ◽  
Landscape Elements ◽  
Great Hungarian Plain ◽  
Ecological Values ◽  
Polygonal Elements ◽  
Basic Hypothesis ◽  
Hungarian Plain

Abstract The research examines the effects of agricultural subsidies on the landscape structure. According to the hypothesis, greening – which has been introduced as part of the European Union’s Common Agriculture Policy (EU CAP) reform –, if it is properly controlled and applied, can be a suitable tool for habitat network development. Landscape elements eligible for greening can function as significant landscape structural elements, and can promote the achievement of goals e.g. in the preservation of biodiversity. As part of this research, field surveys were performed in 2016 and 2017 in the Great Hungarian Plain, where significant landscape elements were assessed and documented in the sample area. During the research, Shape Index and Fractal Dimension Index values for polygonal elements were calculated based on their current extensions in 2016 and in 2017. In line with my basic hypothesis, eligible landscape elements (such as hedgerows, stonewalls, shadoofs and infield trees) do not possess extraordinary ecological values, nor can their persistence be guaranteed solely with greening subsidies. Therefore, they may also not be able to fill their role in the protection of landscape structure and biodiversity in the long term.

scholarly journals Regionalizing time of concentration using landscape structural patterns of catchments

2019 ◽  
Vol 67 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Bahman Jabbarian Amiri ◽  
Junfeng Gao ◽  
Nicola Fohrer ◽  
Jan Adamowski
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Spatial Data ◽  
Landscape Structure ◽  
Shape Index ◽  
Land Use Land Cover ◽  
Catchment Scale ◽  
Time Of Concentration ◽  
The Times ◽  
Dimension Index

Abstract There is an emerging challenge within water resources on how, and to what extent, borrowing concepts from landscape ecology might help re-define traditional concepts in hydrology in a more tangible manner. A stepwise regression model was adopted in this study to assess whether the time of concentration of catchments could be explained by five landscape structure-representing metrics for land use/land cover, soil and geological patches, using spatial data from 39 catchments. The models suggested that the times of concentration of the catchments could be predicted using the measures of four landscape structure-representing metrics, which include contiguity index (r2 = 0.46, p ≤0.05), fractal dimension index (r2 = 0.51, p ≤0.05), related circumscribing circle (r2 = 0.52, p ≤0.05), and shape index (r2 = 0.47, p ≤0.05). The models indicated that the regularity or irregularity in land use/land cover patch shape played a key role in affecting catchment hydrological response. Our findings revealed that regularity and irregularity in the shape of a given patch (e.g., urban and semi-urban, rangeland and agricultural patches) can affect patch functions in retarding and/or increasing flow accumulation at the catchment scale, which can, in turn, decrease or increase the times of concentration in the catchments.

scholarly journals Ostrich eggs geometry

2013 ◽  
Vol 61 (3) ◽  
pp. 735-742 ◽  
Author(s):  
Šárka Nedomová ◽  
Jaroslav Buchar
Keyword(s):  
Fourier Series ◽  
Edge Detection ◽  
Surface Area ◽  
Shape Index ◽  
Egg Volume ◽  
New Approach ◽  
Detection Techniques ◽  
Digital Photo ◽  
Egg Shape ◽  
Precise Quantification

Precise quantification of the profile of egg can provide a powerful tool for the analysis of egg shape for various biological problems. A new approach to the geometry of a Ostrich’s egg profile is presented here using an analysing the egg’s digital photo by edge detection techniques. The obtained points on the eggshell counter are fitted by the Fourier series. The obtained equations describing an egg profile have been used to calculate radii of curvature. The radii of the curvature at the important point of the egg profile (sharp end, blunt end and maximum thickness) are independent on the egg shape index. The exact values of the egg surface and the egg volume have been obtained. These quantities are also independent on the egg shape index. These quantities can be successively estimated on the basis of simplified equations which are expressed in terms of the egg length, L¸ and its width, B. The surface area of the eggshells also exhibits good correlation with the egg long circumference length. Some limitations of the most used procedures have been also shown.

scholarly journals Structural Characteristics of Patches in the Central Lika Landscape – Application of Spatial and Regression Analysis

2020 ◽  
Vol 19 (34) ◽  
pp. 14-39
Author(s):  
Marta Hamzić ◽  
Mladen Pahernik
Keyword(s):  
Regression Analysis ◽  
Landscape Structure ◽  
Structural Characteristics ◽  
Shape Index ◽  
Gis Technology ◽  
Area Index ◽  
Landscape Type ◽  
Landscape Types ◽  
Landscape Patches ◽  
Landscape Patch

This paper analyses the structural characteristics (shape, position and condition) of landscape patches in Central Lika according to landscape types and for the landscape of Central Lika as a whole. A set of indicators for the landscape structure was used along with GIS technology. Interrelation of the structural characteristics of landscape patches were determined using regression analysis. When determining the landscape types of Central Lika, a method based on land cover/land use was applied. For this purpose, data from the CORINE database for the year 2012 were used. At the level of the landscape type in Central Lika and the landscape of Central Lika as a whole, a set of indicators for the landscape structure were used, based on a variety of spatial analysis methods: Mean Shape Index – for the landscape patch shapes; Core Area Index – for the condition of the landscape patches, and Average Nearest Neighbour – for the position of the landscape patches. The most important result of this paper was to confirm the correlation between the shape and condition, and between the shape and position of the landscape patches of Central Lika, while no correlation between the condition and position of the landscape patches of Central Lika was found.

The O–C diagrams of minor planets − a new approach to modelling the rotation

1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss
Keyword(s):  
Error Analysis ◽  
Time Dependence ◽  
Theoretical Work ◽  
Minor Planet ◽  
Minor Planets ◽  
New Approach ◽  
Preliminary Results ◽  
Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

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