黄土丘陵区土地覆盖和生物多样性功能演化及预测

为探究黄土丘陵区土地覆盖和生物多样性功能演化,评价生物多样性保护视角下的最优生境,研究以宁夏彭阳县为研究区,1995、2000、2005、2010、2015年的Landsat TM影像为基础数据,集成3S技术获取土地覆盖时空动态变化特征,采用陷阱法于2012和2013年6—8月在研究区灌草混交林地、乔灌混交林地等6种不同生境内采集地表甲虫样本数据,利用InVEST-Habitate Quality模型评价生物多样性功能,结合采样数据探究最佳生境,借助CA-Marcov模型模拟研究区2020年土地覆盖及生物多样性功能。研究结果表明:(1)1995—2015年彭阳县土地覆盖及生物多样性功能发生显著变化,未利用地减少,城镇用地快速扩张,生境中天然封育草地和水平农田地变化明显,研究期间生物多样性功能经历了退化-优化的转变,2015年最佳;(2)模拟2020年土地覆盖中的水平农田地、城镇用地等较2015年有显著变化,生物多样性功能提高;(3)灌草混交林地是彭阳县生物多样性功能保护的最优生境,生境中固有的"88542"水平沟整地措施可作为当地典型生态恢复的最优模式;(4)InVEST模型和CA-Markov模型综合利用,普适性及准确性较好,研究区水平沟、鱼鳞坑、"88542"等水土保持工程和退耕还林还草、生态功能区划等生态恢复策略的实施和建设成效显著。

Evolution and prediction of land cover and biodiversity function in Loess Hilly Region

This study was conducted explore the evolution of land cover and biodiversity function in the Loess Hilly Region, evaluate the optimal habitat under the perspective of biodiversity conservation, using Pengyang County of Ningxia as the research area, by using Landsat TM images of every 5 years from 1995 to 2015 as the basic data. The 3S technology was used to integrate the characteristics of spatio-temporal dynamics of land cover. From June to August of 2012 and 2013, sample data of ground beetles were collected in 6 different habitats, such as mixed forestland of shrub and grass and mixed forestland of arbor and shrub using the trapping method. The biodiversity function was evaluated using the InVEST-Habitat Quality model, and the best habitat was explored using sampling data. Moreover, land cover and biodiversity function in 2020 were predicted using the CA-Markov model. The result showed that: (1) The land cover and biological diversity of Pengyang County changed significantly from 1995 to 2015, unused land area decreased, urban land rapidly expanded, and natural enclosed grassland and horizontal farmland in the habitat clearly changed; biodiversity function transformed from degradation to optimization during the study period, from which the best biodiversity function was observed in 2015. (2) Compared to 2015, we predicted that the horizontal farmland and urban land of land cover significantly changed in 2020 and the biodiversity function rapidly improved. (3) The mixed forestland of shrub and grass was the best habitat for biodiversity conservation of Pengyang County. The traditional "88542" horizontal ditch of land preparation measure in the habitat may be the best model for ecological restoration in the local area. (4) We observed good universality and high accuracy by utilizing the InVEST model and CA-Markov model, respectively; The implementation and construction of not only soil and water conservation projects, including horizontal ditch, fish scale pit, and "88542", but also ecological restoration strategies such as returning farmland to forest and grass and ecological function zoning are very important and will show remarkable results.