Effect of terrain on landscape patterns and ecological effects by a gradient-based RS and

Effect of terrain on landscape patterns and ecological effects by a gradient-based RS and GIS

analysis

Wenfeng Gong1?Haibo Wang2?Xiaofeng Wang1?Wenyi Fan2?Philip Stott3

【摘 要】AbstractTerrain is an important environment factor that plays a vital role in human development by inf l uencing the spatial layout of land use patterns.The terrain niche index, combined with slope and elevation,can comprehensively present detailed information about spatial differences in terrain and is superior to single terrain factors.We applied remote sensing and geographical information system to terrain gradient,used the non-dimensional distribution index to examine spatial distribution characteristics of various landscape types,and analyzed the ecological effects of landscape were quantitatively on terrain gradients.Eco-environment quality(EEQ)was evaluated using the forestry operation area as the evaluation unit.The spatial distributions in various landscapes were signif icantly inf l uenced by terrain factors,especially by bodies ofwater,cropland and residential land.The spatial distribution varied greatly in different terrain gradients for similar landscape types.The areas associated with good,intermediate and poorEEQwere occupied primarily by natural landscape,semi-natural and largely artif i cial landscapes, respectively.

【期刊名称】林业研究（英文版） 【年(卷),期】2017(028)005 【总页数】12

【关键词】KeywordsTerrain niche index·Spatial distribution characteristics·Distribution index·Eco-environment quality

Introduction

Terrain strongly inf l uences both physical and ecological conditions.It affects

the

distribution

of

vegetation

by

forming

microclimates(e.g.,surface radiation,precipitation and soil moisture conditions)or by disturbance regimes(e.g.,proneness to the occurrence of landslides and wind throws)(Franklin et al.2000;Suzuki and Matsuura 2013).Terrain is also one of the most impact factors linking landscape structure and spatial pattern(Ispikoudis et al.1993;Hobbs 1993).A digital elevation model (DEM),also known as a mode of digital terrain model (DTM)(Xie et al.2011)is a convenient means of representing the continuously varying topographic surface of the earth(Thompson et al.2001;Chaplot et al.2006;Klingseisen et al.2008)and provides a base dataset

that

can

generate

topographic

parameters(Brown

1994;Tappeiner et al.1998).DEMs are widely applied in the analysis of ecological system structures and processes.They are essential for calculating spatial variables(e.g.,terrain slope,aspect and curvature)as independent parameters to analyze correlation between terrain and

species(Li 2013), vegetation pattern distribution,and the impact of terrain onbiodiversity,livelihood and ecosystem services(Xie et al. 2011;Zhang et al.2013;Xu et al.2006;Sani et al.2016).

The terrain-based studies of spatial distribution patterns in landscapes have received attention from Pignatti(1993), Yu et al.(2001),Mottet et al.(2006),Wang et al.(2008), and Weng(2007).However,few have investigated their ecological signif i cance especially in quantitative research on smaller spatial scales in geomorphic environments where natural secondary forestland has been disturbed by human activity.In particular,evaluation of the ecological effects of terrain gradient by quantitative allocation of values to various landscape elements has not been undertaken in depth,especially for the comprehensive evaluation of land use effects(Yue et al.2006). Remote

sensing(RS)integrated

with

geographic

information

system(GIS)technology is particularly useful as a tool used to carry out ecological studies in large mountainous regions with poor accessibility and can be conveniently used to map,monitor and model such mountainous environments(Aplin 2005;Joshi et al.2001;Dorner et al. 2002;Munsi et al.2010).We used RS and GIS to analyze the spatial pattern of the landscape of a mountainous area to determine whether the ecological effects of terrain gradient inf l uenced the local eco-environment quality(EEQ), while the EEQ was the dynamic balance of