Fragmentation of China’s landscape by roads and urban areas

Abstract

China's major paved roadways (national roads, provincial roads, and county roads), railways and urban development are rapidly expanding. A likely consequence of this fast-paced growth is landscape fragmentation and disruption of ecological flows. In order to provide ecological information to infrastructure planners and environmental managers for use in landscape conservation, land-division from development must be measured. We used the effective-mesh-size (M eff) method to provide the first evaluation of the degree of landscape division in China, caused by paved roads, railways, and urban areas. Using M eff , we found that fragmentation by major transportation systems and urban areas in China varied widely, from the least-impacted west to the most impacted south and east of China. Almost all eastern provinces and counties, especially areas near big cities, have high levels of fragmentation. Several eastern-Chinese provinces and biogeographic regions have among the most severe landscape fragmentation in the world, while others are comparable to the leastdeveloped areas of Europe and California. Threatened plant hotspots and areas with high mammal species diversity occurred in both highly fragmented and less fragmented areas, though future road development threatens already moderately divided landscapes. To conserve threatened biodiversity and landscapes, we recommend that national and regional planners in China consider existing land division before making decisions about further road development and improvement.

Disturbance impacts of land use change on biodiversity conservation priority areas across China: 1990–2010

“…From 2000-2010, the increase of the built-up land area in East China was about 2.55 times the increase from 1990 to 2000. It is notable that the expanded area of built-up land with less vegetation distribution was mainly converted from semi-natural cropland, thus exerting considerable pressure on biodiversity conservation (Li et al, 2010;McDonald et al, 2008;Seto et al, 2012;Wang et al, 2007). Cropland reclamation mostly occurred in Northeast and Northwest China.…”

“…However, habitat fragmentation resulting from land use change is also an important disturbance factor, and a primary cause of species loss (Baral et al, 2014;Li et al, 2010;Newmark et al, 2011). Habitat fragmentation results in a reduction in area, an increase in remnant isolation, the creation of edge, and an alteration in the habitat structure of the remnants, all of which may contribute either directly or indirectly to changes in species survival (Newmark et al, 2011).…”

“…Built-up land areas have rapidly expanded, mainly in eastern China, and have gradually spread to Central and Western China. Woodland first decreased and then increased, while grassland has continued to decrease (Li et al, 2010;Liu et al, 2014a). The purpose of this paper is to assess the disturbance impacts of land use changes between 1990 and 2010 on different categories of biodiversity conservation priority areas at national and regional scales by constructing an Ecosystem Comprehensive Anthropogenic Disturbance Index (ECADI).…”

Landscape network approach to assess ecological impacts of road projects on biological conservation

“…During the past several decades, China has accomplished many key transportation projects, including large-scale construction of high-speed highway and high-speed railway systems (Liu et al, 2008). By 2025, it is estimated that an additional 20 000 km expressway will be completed to reach a total length of 85 000 km (Li et al, 2010). The interactions between these projects and regional ecosystems are of particular concerns to government, researchers, and the public (Chen et al, 2007).…”

“…On large scales, the expansion and extension of road networks causes many ecological effects (Li et al, 2010). For example, road development is a primary cause of habitat fragmentation and may result in sudden extinctions of native species.…”