以数码照相法估算生物土壤结皮盖度

doi:10.7522/j.issn.1000-694X.2013.00269

摘要/Abstract

摘要：

生物土壤结皮(BSC)是由藻类、地衣、苔藓和土壤中微生物形成的一类有机复合体,是干旱荒漠地区主要的地表覆被类型。由于藻、地衣和苔藓呈非连续性斑块状分布,准确估算它们的盖度比较困难。传统的估算方法主要是样方法和遥感影像法,样方法在野外操作中虽然比较精确但是费时,遥感影像法虽然快速但是误差大。本文试图通过数码照相法获取BSC地表分布信息,然后利用最大似然监督分类法对苔藓结皮、地衣结皮和藻结皮盖度进行分类计算,并用野外原位调查进行验证。结果表明,本文采用的照相法与传统样方法的相关性达到了94.45%,照相法可以有效地用于BSC盖度的估算,提高了盖度估算的效率。

关键词: 数码照相, 生物土壤结皮, 盖度, 监督分类

Abstract:

Biological soil crusts (BSC), consisting of cyanobacteria, algae, lichens and mosses, are widely distributed in arid and semi-arid regions. Due to resource heterogeneity, the distribution patterns of algae, lichens and mosses are discontinuous and patchy. Thus, the BSC coverage is difficult to be estimated in an accurately and quickly way, particularly in the separation of coverage from each component. Quadrat method and remote-sensing image are often used to estimate the coverage of BSCs. However, both of the two traditional methods have disadvantages. Quadrat method is difficult and time-consuming, although it is relatively accurate. Similarly, remote-sensing image can be used to estimate the coverage of BSC in regional scale, but the low accuracy limits its well development in specific scale. In this paper, the distributional data of BSC were obtained from digital photos. Coverage of different BSC types (algal crusts, lichen crusts and moss crusts) was calculated by using maximum likelihood supervised classification. In order to validate the accuracy, some sampling point sites were randomly selected to determine the correlation between the coverage analyzed by supervised classification and in method of quadrat. There existed significant correlations (R2=94.45%, p<0.01) between the two methods. The results indicated that method of digital photos is a proper way to estimate the coverage of different BSC types, and the estimation efficiency could be greatly increased.

Key words: digital photo, biological soil crusts, coverage, supervised classification

中图分类号:

Q948.15

吴林1,2, 张元明1. 以数码照相法估算生物土壤结皮盖度[J]. 中国沙漠, 2013, 33(6): 1810-1815.

WU Lin1,2, ZHANG Yuan-ming1. Coverage Estimation on Biological Soil Crusts Based on Digital Photos[J]. JOURNAL OF DESERT RESEARCH, 2013, 33(6): 1810-1815.

参考文献

[1]Belnap J.The world at your feet: desert biological soil crusts[J].Frontiers in Ecology and the Enviroment,2003,1(4):181-189.

[2]Beymer R J,Klopatek J M.Potential contribution of carbon by microphytic crusts in pinyong-juniper woodlands[J].Arid Soil Research and Rehabilitation,1991,5(3):187-198.

[3]苏延桂,李新荣,贾小红,等.温带荒漠区藻结皮固氮活性沿时间序列的变化[J].中国沙漠,2012,32(2):421-427.

[4]Belnap J,Gillette D A.Disturbance of biological soil crusts:impacts on potential wind erodibility of sandy desert soils in southeastern Utah[J].Land Degradation & Development,1997,8(4):355-362.

[5]Cornelissen J H C,Callaghan T V,Alatalo J M,et al.Global change and arctic ecosystems:is lichen decline a function of increases in vascular plant biomass?[J] Journal of Ecology,2001,89(6):984-994.

[6]Eldridge D J,Greene R S B.Microbiotic soil crusts:a review of their roles in soil and ecological processes in the rangelands of Australia[J].Australian Journal of Soil Research,1994,32(3):389-415.

[7]Belnap J,Welter J R,Grimm N B,et al.Linkages between microbial and hydrologic processes in arid and semiarid watersheds[J].Ecology,2005,86(2):298-307.

[8]刘艳梅,李新荣,何明珠,等.生物土壤结皮对土壤微生物量碳的影响[J].中国沙漠,2012,32(3):669-673.

[9]苏延桂,李新荣,张景光,等.生物土壤结皮对土壤种子库的影响[J].中国沙漠,2006,26(6):997-1001.

[10]李新荣,陈应武,贾荣亮.生物土壤结皮:荒漠昆虫食物链的重要构建者[J].中国沙漠,2008,28(2):245-248.

[11]李新荣,贾玉奎,龙利群,等.干旱半干旱地区土壤微生物土壤结皮的生态学意义及若干研究进展[J].中国沙漠,2001,21(1):4-11.

[12]吴永胜,哈斯,屈志强.影响生物土壤结皮在沙丘不同地貌部位分布的风因子讨论[J].中国沙漠,2012,32(4):980-984.

[13]Li X R,He M Z,Zerbe S,et al.Micro-geomorphology determines community structure of biological soil crusts at small scales[J].Earth Surface Processes and Landforms,2010,35(8):932-940.

[14]Lalley J S,Viles H A,Copeman N,et al.The influence of multi-scale environmental variables on the distribution of terricolous lichens in a fog desert[J].Journal of Vegetation Science,2006,17(6):831-838.

[15]Eldridge D J,Tozer M E.Environmental factors relating to the distribution of terricolous bryophytes and lichens in semi-arid eastern Australia[J].Bryologist,1997,100(1):28-39.

[16]Kidron G J,Barzilay E,Sachs E.Microclimate control upon sand microbiotic crusts,western Negev Desert,Israel[J].Geomorphology,2000,36:1-18.

[17]Rogers R W.Soil surface lichens on a 1500 kilometre climatic gradient in subtropical eastern Australia[J].Lichenologist,2006,38(6):565-576.

[18]Ustin S L,Santos M J,Kefauver S C,et al.Remote sensing of biological soil crust under simulated climate change[J].Remote Sensing of Environment,2009,113:317-328.

[19]White M A,Asner G P,Nemani R R,et al.Measuring fractional cover and leaf area index in arid ecosystems:digital camera,radiation transmittance,and laser altimetry methods[J].Remote Sensing of Environment,2000,74(1):45-57.

[20]Zhou Q,Robson M.Automated rangeland vegetation cover and density estimation using ground digital images and a spectral-contextual classifier[J].International Journal of Remote Sensing,2001,22(17):3457-3470.

[21]宋雪峰,董永平,单丽燕,等.用数码相机测定草地盖度的研究[J].内蒙古草业,2004,16(4):1-6.

[22]张学霞,朱清科,吴根梅,等.数码照相法估算植被盖度[J].北京林业大学学报,2008,30(1):164-169.

[23]Chen J,Zhang Y M,Wang L,et al.A new index for mapping lichen-dominated biological soil crusts in desert areas[J].Remote Sensing of Environment,2005,96(2):165-175.

[24]Weber B,Olehowski C,Knerr T,el al.A new approach for mapping of Biological Soil Crusts in semidesert areas with hyperspectral imagery[J].Remote Sensing of Environment,2008,112(5):2187-2201.

[25]Ustin S L,Santos M J,Kefauver S C,et al.Remote sensing of biological soil crust under simulated climate change[J].Remote Sensing of Environment,2009,113:317-328.

[26]Bowker M A,Johnson N C,Belnap J,et al.Short-term monitoring of aridland lichen cover and biomass using photography and fatty acids[J].Journal of Arid Environments,2008,72(6):869-878.

[27]任杰,柏延臣,王锦地.从数码照片中快速提取植被覆盖度的方法研究[J].遥感技术与应用,2010,25(5):719-724.

[28]张元明,陈晋,王雪芹,等.古尔班通古特沙漠生物土壤结皮的分布特征[J].地理学报,2005,60(1):53-60.