QUANTIFYING LANDSCAPE FRAGMENTATION VIA EFFECTIVE MESH SIZE LANDSCAPE METRIC: CASE OF ALBANIA

Fragmentation is a disruption in the connectivity of landscapes. The aims of this paper are (i) to quantitatively assess the fragmentation rates in three landscape units located in a hydrocarbon basin, and (ii) to model their behavior between 2001 and 2013 using landscape metrics at different scales of resolution. The following metrics were selected using principal component analysis (PCA): The Clumpiness Index (CLUMPY), patch density (PD), perimeter-area fractal dimension (PAFRAC) and effective mesh size (MESH). Results from our investigations pointed out that hydrocarbon activity increased the fragmentation at the sites. In particular, the CLUMPY index increased in all three landscape units, the average of PD decreased from 60 to 14 patches per 100 hectares, whereas the mean of MESH was quite constant, however, due to oil production, it decreased mainly in the coastal valleys. Finally, the PAFRAC also decreased at sites with oil production, being more evident in the plateau and coastal canyons. As a whole, outputs from our analyses clearly pointed out that the monitoring of landscape fragmentation trends in arid and semi-arid zones can be successfully achieved using metrics derived from satellite spectral information.

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Recent Shrinkage and Fragmentation of Bluegrass Landscape in Kentucky

Remote Sensing ◽

10.3390/rs12111815 ◽

2020 ◽

Vol 12 (11) ◽

pp. 1815

Author(s):

Bo Tao ◽

Yanjun Yang ◽

Jia Yang ◽

Ray Smith ◽

James Fox ◽

...

Keyword(s):

Land Use ◽

Land Cover ◽

Mesh Size ◽

Landscape Fragmentation ◽

Climate Mitigation ◽

Fragmentation Model ◽

Cultural Significance ◽

Effective Mesh Size ◽

Grassland Conversion ◽

Bluegrass Region

The Bluegrass Region is an area in north-central Kentucky with unique natural and cultural significance, which possesses some of the most fertile soils in the world. Over recent decades, land use and land cover changes have threatened the protection of the unique natural, scenic, and historic resources in this region. In this study, we applied a fragmentation model and a set of landscape metrics together with the satellite-derived USDA Cropland Data Layer to examine the shrinkage and fragmentation of grassland in the Bluegrass Region, Kentucky during 2008–2018. Our results showed that recent land use change across the Bluegrass Region is characterized by grassland decline, cropland expansion, forest spread, and suburban sprawl. The grassland area decreased by 14.4%, with an interior (or intact) grassland shrinkage of 5%, during the study period. Land conversion from grassland to other land cover types has been widespread, with major grassland shrinkage occurring in the west and northeast of the Outer Bluegrass Region and relatively minor grassland conversion in the Inner Bluegrass Region. The number of patches increased from 108,338 to 126,874. The effective mesh size, which represents the degree of landscape fragmentation in a system, decreased from 6629.84 to 1816.58 for the entire Bluegrass Region. This study is the first attempt to quantify recent grassland shrinkage and fragmentation in the Bluegrass Region. Therefore, we call for more intensive monitoring and further conservation efforts to preserve the ecosystem services provided by the Bluegrass Region, which has both local and regional implications for climate mitigation, carbon sequestration, diversity conservation, and culture protection.

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The influence of landscape fragmentation, expressed by the ‘Effective Mesh Size Index’, on regional patterns of vascular plant species richness in Lower Saxony, Germany

Landscape and Urban Planning ◽

10.1016/j.landurbplan.2016.01.012 ◽

2016 ◽

Vol 153 ◽

pp. 209-220 ◽

Cited By ~ 8

Author(s):

Inga Schmiedel ◽

Heike Culmsee

Keyword(s):

Species Richness ◽

Plant Species ◽

Vascular Plant ◽

Mesh Size ◽

Landscape Fragmentation ◽

Plant Species Richness ◽

Lower Saxony ◽

Regional Patterns ◽

Size Index ◽

Effective Mesh Size

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Research on heat transfer characteristics of fractal-generated turbulence based on large eddy simulation

Thermal Science ◽

10.2298/tsci181122108d ◽

2019 ◽

Vol 23 (6 Part B) ◽

pp. 3993-4004

Author(s):

Chengdong Duan ◽

Yuncong Jiang ◽

Nannan Wu ◽

Qiwen Xu ◽

Lijun Wang

Keyword(s):

Heat Transfer ◽

Boundary Layer ◽

Flow Field ◽

Large Eddy Simulation ◽

Cross Section ◽

Mesh Size ◽

Eddy Simulation ◽

Large Eddy ◽

Effective Mesh Size ◽

Layer Region

Turbulence plays an important role in the fields of heat and mass transfer and enhanced chemical reaction. In order to explore the effect of grid-generated turbulence on flow heat transfer, in this paper, three different fractal grid structures with the same blocking ratio ?, effective mesh size Meff and thickness ratio tr= t max/t min (Case1: The grid cross-section is a triangle, Case2: the grid cross-section is an inverted triangle, Case3:the grid cross-section is square, Case4:no grid) and without the grid were simulated based on large eddy simulation. The aim of this simulation is to explain the evolution characteristics and heat transfer mechanism of turbulent flow field under the four cases. The results show that, in the same initial condition, Case 2 can generate the highest turbulence intensity and the feature of heat transfer on the cylindrical surface is more uniform. In Case 3, the boundary-layer in the flow field is separated earlier, and more vortices are excited to enhance the heat transfer than other cases in the boundary-layer region. The surface average Nusselt number is 1.3 times than that of Case 4.

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Fragmentation degree and effective mesh size of nature-protected areas of the Western Ukraine

Studia Biologica ◽

10.30970/sbi.0902.440 ◽

2015 ◽

Vol 9 (2) ◽

pp. 207-210

Author(s):

O. Reshetylo ◽

Keyword(s):

Protected Areas ◽

Mesh Size ◽

Western Ukraine ◽

Effective Mesh Size ◽

Fragmentation Degree

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Roads and Roadless Areas in Cyprus: Implications For The Natura 2000 Network

Journal of Landscape Ecology ◽

10.2478/jlecol-2014-0010 ◽

2014 ◽

Vol 7 (1) ◽

pp. 75-90 ◽

Cited By ~ 8

Author(s):

Maria Zomeni ◽

Ioannis. N. Vogiatzakis

Keyword(s):

Nature Conservation ◽

Road Network ◽

Mesh Size ◽

Natura 2000 ◽

Road Density ◽

Natura 2000 Network ◽

The Road ◽

Effective Mesh Size ◽

Roadless Areas ◽

The Relationship

Abstract The road network in Cyprus has seen an 88% increase in the last 20 years. This expansion has not been followed by any kind of assessment on the effects of the network on nature conservation. This is the first island-wide quantitative assessment of the size, character (surface types), pervasiveness and distribution of the road system with particular reference to Natura 2000 network on the island. We mapped roadless areas (i.e. areas at least one km away from nearest road) for the whole island and examined the spatial distribution with respect to Natura 2000. We tested the relationship between overall road density and road density of different road categories within terrestrial Natura 2000 sites to four zones which were defined on the basis of landform, principal land use and ownership. We employed three indices i.e. effective mesh size, splitting and division to measure fragmentation caused by the road network within Natura 2000 and investigated the relationship between road density and the above fragmentation metrics. Mean road density in Cyprus is 2.3 km/km2 which is comparable to road density values recorded in other Mediterranean countries such as France, Spain and Italy, which have much larger area and population. Roadless areas cover 4.5% of the island, and despite being scattered 80% is found within Natura 2000, which demonstrates the added value of the network for nature conservation. Road expansion has taken place throughout the island with the same intensity irrespectively of the zones examined. Fragmentation has been lower in sites on mountainous areas where sites are larger and under state ownership. Road density is negatively correlated (r = - 0.383, p = 0.05) with effective mesh size and positively correlated with both landscape division (r = 0.376, p = 0.05) and splitting index (r = 0.376, p = 0.05). Results corroborate that spatial configuration is an important property of the road network in addition to traffic load, length and density.With the shift from site based conservation to landscape level there is a challenge for integrating technical, human and ecological requirements into infrastructure planning.

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The fine structure of capture nets of larval Philopotamidae (Trichoptera), with special emphasis on Dolophilodes distinctus

Canadian Journal of Zoology ◽

10.1139/z76-208 ◽

1976 ◽

Vol 54 (10) ◽

pp. 1788-1802 ◽

Cited By ~ 23

Author(s):

J. Bruce Wallace ◽

Diane Malas

Keyword(s):

Small Volume ◽

Small Diameter ◽

Mesh Size ◽

Silk Gland ◽

Microscope Examination ◽

Fine Particulate ◽

Rectangular Mesh ◽

Effective Mesh Size ◽

Flowing Waters ◽

Scanning Electron

Philopotamid larvae spin, in flowing waters, capture nets that have the smallest mesh opening sizes recorded among trichopterans. Sac-like nets of final-instar Dolophilodes distinctus are up to 6 cm long and 8 to 15 cm in circumference. Both larval nets and mesh opening sizes increase with instar, those of final instars being about 0.5 × 5.5 μm. Based on scanning electron microscope examination, a probable net construction sequence is proposed. The structure of the silk-gland opening suggests that a larva can simultaneously spin about 70 of the smallest (0.15 μm diameter) silk strands. Mature larvae may have about 100 million meshes per capture net and have silk strands totaling over 1.0 km in length, but the small diameter of these strands represents a small volume of silk. Food of D. distinctus consists primarily of fine particulate organic matter (FPOM), with associated microflora, and some diatoms. Larvae possess specialized feeding structures for collection of FPOM from the net. Nets of a Wormaldia sp. examined consisted of several layers of elongate rectangular meshes (about 0.4 × 3.7 μm). Underlying net layers are arranged diagonally, resulting in further reductions in effective mesh size to dimensions of about 0.4 × 0.4 μm. Larval nets of Chimarra spp. examined have both elongate rectangular mesh-opening shapes and nets apparently consisting of randomly arranged silk strands.

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Spatially Variable Relationships between Karst Landscape Pattern and Vegetation Activities

Remote Sensing ◽

10.3390/rs12071134 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1134 ◽

Cited By ~ 2

Author(s):

Wenjuan Hou ◽

Jiangbo Gao

Keyword(s):

Land Use ◽

Landscape Pattern ◽

Structural Changes ◽

Vegetation Index ◽

Morphological Characteristics ◽

Mesh Size ◽

Landscape Fragmentation ◽

Vegetation Activity ◽

Function Correlation ◽

The Impact

Based on the theories of structure–function correlation in Geography, and landscape pattern-ecological function correlation in Landscape Ecology, the correlation between land use fragmentation and vegetation activity was quantified. Effective mesh size (meff) was calculated to represent landscape fragmentation for land use, and the normalized difference vegetation index (NDVI) was used to reflect vegetation activity. The geographically weighted regression (GWR) model was applied to explore the spatial non-stationary relationship between meff and NDVI in a karst basin of the southwestern China, where environmental factors (i.e., climate, topography, and vegetation) are spatially heterogeneous. The spatial variation and scale dependence of landscape fragmentation and its relationship with vegetation activity, as well as the influence of lithology types and landforms relief, were considered. Firstly, the optimal ‘slide window’ size for landscape fragmentation was determined to be 500 m, and spatial pattern of meff displayed clear heterogeneity with a serious degree of fragmentation. Landscape fragmentation was more severe in carbonate areas than non-carbonate areas, reflecting the influence of landforms relief. More serious fragmentation in dolomite areas meant that the impact of human activities on the landscape morphological characteristics was much more significant than that in the limestone areas with steeper slope. Multi-scale analysis was used to verify a neighborhood size of 7 km for GWR in the study area. Negative effects on vegetation activity from landscape structural changes were more significant in limestone areas, which may be due to the more vulnerable ecosystems there. This research can provide scientific guidance for landscape management in karst regions as it considers the multi-scaled and spatially heterogeneous effects of lithology, geomorphology, and human factors on landscape structure and its correlation with vegetation activity.

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Assessing Landscape Sensitivity Based on Fragmentation Caused by the Artificial Barriers in Hungary

Journal of Environmental Geography ◽

10.2478/v10326-012-0005-1 ◽

2013 ◽

Vol 6 (1-2) ◽

pp. 37-47 ◽

Cited By ~ 1

Author(s):

Teodóra Bata ◽

Gábor Mezősi

Keyword(s):

Landscape Metrics ◽

Patch Size ◽

Mesh Size ◽

Landscape Fragmentation ◽

Effective Population ◽

Landscape Unit ◽

Landscape Sensitivity ◽

The Stability ◽

Landscape Units ◽

Degree Of Fragmentation

Abstract Artificial barriers significantly disturb the landscape unit. Roads split the contiguous landscape units, thus basically modi fying their ecological characters. The more artificial barriers are constructed in the landscape, the more fragmented it is. Theref ore, the contiguous landscape unit is divided into two or more patches, weakening resilience and stability of ecological systems. During decrease in patch size, the stability reduces until the patch size is at its minimum viable or effective population size. In current study analysing the degree of fragmentation caused by artificial barriers in meso-scale landscape units (meso-regions) we can get an overall picture about changes in their stability and sensitivity. The major aims of this study is to investigate the fragmentation of landscape units caused by three types of artificial barriers (roads, railways and settlements) in micro-regions, and to measure the degree of fragmentation and its spatial-temporal (1990, 2011 and future scenario to 2027) changes using mathemat ical/ statistical analysis and landscape metrics (Number of Patches, Division, Landscape Splitting Index and Effective Mesh Size). By calculating landscape fragmentation metrics, the micro-regions are identified, which must be protected with high priority in the future. In the planning processes, type and position of artificial barriers could be more properly determined by calculation of these landscape metrics.

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