Changes In Forest Fragmentation Research Articles

The Effectiveness of Municipal Comprehensive Planning in Mitigating Forest Fragmentation

To mitigate forest fragmentation, it is critical to investigate the factors that contribute to it. Considerable research examines various factors shaping forest fragmentation, but these studies have not typically identified land use planning as an important factor. Our study helps fill this gap in the literature. To examine the influence of land use planning on forest fragmentation, we assessed the quality of 29 municipal comprehensive plans with respect to forest protection in Wisconsin, U.S.A., a sample drawn from a spatial analysis of forest fragmentation dynamics from 2001 to 2011. We found that the comprehensive plans of communities that have experienced lower-than-expected forest fragmentation change were, on average, of significantly higher quality than those of the communities that have experienced higher-than-expected forest fragmentation change during this period. We conclude that the quality of community-based comprehensive plans, especially the strength and breadth of policies addressing forestland, matters in mitigating the fragmentation of forestland.

Multiscale analysis of patch and landscape characteristics of forest fragmentation in Liaoning Province, China

Measuring dynamic changes in forest fragmentation is essential for protecting natural resources as part of regional land use planning. We investigated spatiotemporal dynamics of patch and landscape characteristics of forest fragmentation in Liaoning, China, from 2000 to 2010 by multiscale analysis based on the neighbor rule and landscape metrics. Several policy recommendations were proposed to prevent widespread loss of regional forest land. From 2000 to 2010, the area of forest loss decreased; forest patches decreased in size, subdivided, and disappeared in Liaoning at the patch level. During the study period, the transformation of forest land in most eastern counties remained in the middle phase of land transformation, with shrinkage being the main process of forest fragmentation (accounting for approximately 61.59% of lost forest area in 2000–2005 and 51.33% in 2005–2010). In contrast, the transformation of forest land in most western counties was in the later phases, with subdivision and attrition being the main processes. The areas of the four fragmentation processes decreased with increasing elevation, slope, and distance from residential lands, rivers, and roads. In most southern counties of Liaoning, forest fragmentation intensified at the landscape level. From 2000 to 2005, forest landscape patches close to rivers became irregular, isolated, and divided. However, these fragmentation metrics were not significantly related to physical, socioeconomic, and other spatial factors at the landscape level during the entire study period. Differences observed across multiple scales and levels may be used to monitor ecological processes and protect natural resources in China.

Forest-Cover Increase Does Not Trigger Forest-Fragmentation Decrease: Case Study from the Polish Carpathians

Understanding the causes and consequences of forest-fragmentation changes is critical for preserving various ecosystem services and to maintain biodiversity levels. We used long-term (1860s–2010s) and large-scale data on historical forest cover in the Polish Carpathians to identify the trajectories of forest fragmentation. Past forest cover was reconstructed for the 1860s, 1930s, 1970s and 2010s using historical maps and the contemporary national database of topographic objects. We analyzed forest-cover changes in 127 randomly selected circular test areas. Forest fragmentation was quantified with GuidosToolbox software using measures based on a landscape hypsometric curve (LHC). Despite a general increase in forest cover, forest fragmentation showed divergent trajectories: a decrease between the 1860s and 1930s (in 57% of test areas), and an increase between the 1930s and 1970s and between the 1970s and 2010s (in 58% and 72% of test areas, respectively). Although deforestation typically involves the increasing fragmentation of forest habitats, we found that forest expansion may not necessarily lead to more homogenous forested landscape, due to complex land-ownership and land-use legacy patterns. This is both a challenge and an opportunity for policy makers to tune policies in such a way as to maintain the desired fragmentation of forest habitats.

A global evaluation of forest interior area dynamics using tree cover data from 2000 to 2012

Published maps of global tree cover derived from Landsat data have indicated substantial changes in forest area from 2000 to 2012. The changes can be arranged in different patterns, with different consequences for forest fragmentation. Thus, the changes in forest area do not necessarily equate to changes in forest sustainability. The objective is to assess global and regional changes in forest fragmentation in relation to the change of forest area from 2000 to 2012. Using published global tree cover data, forest and forest interior areas were mapped in 2000 and 2012. The locations of forest interior change were compared to the locations of overall forest change to identify the direct (pixel level) and indirect (landscape level) components of forest interior change. The changes of forest interior area were compared to the changes of total forest area in each of 768 ecological regions. A 1.71 million km2 (3.2 %) net loss of global forest area translated to a net loss of 3.76 million km2 (9.9 %) of forest interior area. The difference in loss rates was consistent in most of the 768 ecological regions. The indirect component accounted for 2.44 million km2 of the net forest interior change, compared to 1.32 million km2 that was attributable to the direct component. Forest area loss alone from 2000 to 2012 underestimates ecological risks from forest fragmentation. In addition to the direct loss of forest, there was a widespread shift of the remaining global forest to a more fragmented condition.

Temporal Change in Fragmentation in China’s Primary Forest Ecoregions

Forests are of interest from a wide range of perspectives simply because they serve many purposes, including timber products, watershed protection, wildlife habitat, carbon sequestration, recreational opportunities and aesthetic values. However, degradation or changes in forest ecosystem function and condition arise from changes in forest loss and fragmentation. In this study, based on the 1995 and 2005 land use/cover data for China, mathematical morphology coupled with the percolation theory was adopted to temporally assess changes in forest fragmentation patterns in 36 forest ecosystems of China through classifying each forest pixel into one of the six fragmentation components (interior, perforated, patch, edge, transitional and undetermined) by using the sliding window analysis technique to establish spatially explicit forest fragmentation maps. Additionally, landscape indices were also involved in the assessment of forest fragmentation status and trends. Results revealed that an accelerated fragmentation was observed in most forest ecoregions, especially in Daurian forest stepp, Hainan Island monsoon rain forests, and Northern Indochina subtropical forests with a sharp change in fragmentation patterns. The increased fragmentation was evidenced by a decreasing share of interior forest and an increasing trend of area share for perforated forest, patch forest and edge forest. In addition, derivations of geospatial indices from another three selected typical forest ecoregions also further confirmed the accelerated fragmentation. The increased fragmentation in most forest ecoregions of China was primarily driven by anthropogenic disturbances, including illegal logging, agricultural encroachment, infrastructure construction. Additionally, forest fragmentation maps provided valuable insights and implications regarding the development of land use strategies, habitat planning for rare and endangered species, and sustainable forest management. By utilizing the changes in fragmentation maps, such as the variation in location of the interior and perforated components, human can make effective risk assessments and crucial targets for protection and remediation.

Monitoring spatial and temporal pattern of Paneveggio forest (northern Italy) from 1859 to 2006

Abstract: This paper presents the results of a forest cover analysis over a time span of 150 years in a protected area of Eastern Trentino (Northern Italy), Paneveggio Pale di S. Martino Nature Park. With the aid of Grass GIS two historical maps (1859 and 1936) and a set of aerial photographs taken from 1945 to 2006 have been analysed, orthorectified and classified with a supervised method, in order to derive a series of forest cover maps. Techniques applied and problems encountered in using heterogeneous material are discussed. The research shows that from 1859 to the present the increase of forest cover is about 25%, due to the reduced impact of forestry and farming. Timberline dynamics have also been considered; an average growth of about 1 m/year has been estimated for the last 150 years and the data have been compared with the timberline cartography and to field surveys. Timberline estimation for recent years appears to be affected mainly by lower human pressure while the relationship with climate changes is difficult to evaluate. Landscape metrics were used to quantify the changes in forest fragmentation and to identify three core areas that have remained unchanged over time. This case study fills a gap of knowledge about the history of forest cover in the area, shows how multi temporal analysis can support protected area management. This study has been requested by the Park managers, a sign t that landscape planners are becoming aware of past landscape importance.

Temporal change in fragmentation of continental US forests

Changes in forest ecosystem function and condition arise from changes in forest fragmentation. Previous studies estimated forest fragmentation for the continental United States (US). In this study, new temporal land-cover data from the National Land Cover Database (NLCD) were used to estimate changes in forest fragmentation at multiple scales for the continental US. Early and late dates for the land-cover change data were ca. 1992 and ca. 2001. Forest density was used as a multi-scale index of fragmentation by measuring the proportion of forest in neighborhoods ranging in size from 2.25 to 5314.41 ha. The multi-scale forest density maps were classified using thresholds of 40% (patch), 60% (dominant), and 90% (interior) to analyze temporal change of fragmentation. The loss of dominant and interior forest showed distinct scale effects, whereas loss of patch forest was much less scale-dependent. Dominant forest loss doubled from the smallest to the largest spatial scale, while interior forest loss increased by approximately 80% from the smallest to the second largest spatial scale, then decreased somewhat. At the largest spatial scale, losses of dominant and interior forest were 5 and 10%, respectively, of their ca. 1992 amounts. In contrast, patch forest loss increased by only 25% from the smallest to largest spatial scale. These results indicate that continental US forests were sensitive to forest loss because of their already fragmented state. Forest loss would have had to occur in an unlikely spatial pattern in order to avoid the proportionately greater impact on dominant and interior forest at larger spatial scales.

Tropical deforestation and species endangerment: the role of remote sensing

Initial results of a pilot study to link remotely-sensed information on tropical forest loss to field-based information on species endangerment are reported here. LANDSAT multispectral scanner (MSS) imagery from 1973 and 1988 were used to estimate net forest removal (29% of forest area), regrowth (7% of forest area, including possible artifactual errors), and forest edges in Mabira Forest in southeastern Uganda during the 15-year period. Of the forest remaining, the percentage that was heavily disturbed increased from 18% to 42%. This change in forest density was observable with the MSS imagery. The total forest edge-to-area ratio (including edges interior to the forest boundary) increased by 29% over the period. Although four distinct types of closed tropical forest, based on structure or dominance, could be recognized on the ground, the types could not be distinguished by differences in spectral reflectance in the four MSS bands. Closed tropical forest could be readily distinguished from exotic conifer plantations, banana plantations, and other non-forest vegetation types. Field measurements in Mabira and other Ugandan rain forests, and in rain forest isolates on the Atherton Tableland of North Queensland, are being made to relate changes in forest fragmentation to resulting changes in species abundance, structural form of the forests, and morphological diversity of target populations. Possible applications of conservation biology theory and modeling to these data are briefly discussed.