Karst environment is distributed largely in Southwest China. Soil and vegetation are the most sensitive elements to the variation of Karst environment. The weathering of carbonate is important soil formation mechanism in Karst areas, but its soil forming ability is so poor that soil layer thickness becomes thin by the water erosion, though the soil loss is insignificant but serious. The character of Karst plants is firmly connected with the environment condition, i.e., lack of water, richness of Ca²⁺, poor soil and shortage of organic matter, the plants have low pace growth and low life-form resource, and is vulnerable under the disturbance of irrational human activities. Therefore, the rocky desertification is the end of Karst ecosystem degradation, but these degradation processes are depended on different land use patterns. Further, this paper discusses the assessment of the fragility on Karst ecosystem and raises vital problems on how to improve productivity. Finally, this paper suggests some solutions about rehabilitation of ecology to solve the problems of man-land relation in Karst environment in Southwest China.

我国西南喀斯特地区石漠化问题严重,虽然通过石漠化治理措施遏制了整体扩张趋势,但是治理形势并不乐观,生态环境质量有待进一步改善。针对中国西南石漠化治理存在的治理成果难以有效维持、无法彻底消除人地矛盾、治理难度不断提高等问题,在系统梳理西南喀斯特地区的特殊性、石漠化成因、西南喀斯特地区石漠化综合治理模式的基础上,从重视区域整体治理与系统修复、探索喀斯特生态产品价值实现机制与途径、加强喀斯特地区生态补偿、探索喀斯特地区社会-生态系统的协同机制四方面,提出了面向区域整体治理与绿色发展的对策建议,为我国西南地区生态环境和社会经济协同高质量发展提供科学参考。

Despite that the expansion of severe rocky desertification in the karst areas of southwest China has been initially curbed, the situation allows no optimism and the eco-environment needs to be further improved. Effective efforts are required to maintain the achievements of desertification control; the contradiction between human and land cannot be eradicated; and the difficulty of controlling desertification has been escalating. In view of this, we summarized the specific characteristics of the karst areas in southwest China, the causes of rocky desertification, as well as the comprehensive management mode. On this basis, we put forward suggestions on comprehensive regional control and green development in four aspects: highlighting holistic management and systematic restoration, exploring pathways of value realization of eco-products, strengthening eco-compensation, and seeking a coordinated social and ecological system. The suggestions are expected to provide scientific reference for the coordinated high-quality development of eco-environment and social economy in southwest China.

石漠化是中国西南喀斯特地区面临的重要环境问题之一,其演化过程和驱动机制分析一直是相关研究领域的难点和热点,尤其是人类活动的影响分析方面仍有待于进一步研究。论文选择贵州石漠化极其严重的关岭县为研究区,利用2010年SPOT5/ALOS数据、2015年的高分一号/资源三号数据等,结合地面调查、采用目视解译的方法获得了2010—2015年石漠化分布、演化过程及驱动因素等信息;在系统分析石漠化的空间分布及演化过程的基础上,着重分析土地利用类型、社会经济水平及石漠化治理工程等人类活动因素对贵州石漠化演化的影响。研究结果表明：① 关岭县石漠化土地占有很大比重(2015年占总土地面积的45%以上)且以中度石漠化为主;② 石漠化总体上得到明显改善,石漠化土地面积逐年减少,尤其是重度石漠化和极重度石漠化土地明显减少,但仍有部分石漠化土地的状况在恶化。③ 人类活动对石漠程度和演化过程具有重要的影响,首先,土地利用类型尤其是灌木林、旱地和有林地对石漠化演化起着重要的作用;其次,人口密度较大和GDP较高的地区,石漠化程度也较高且石漠化恢复治理的效果越不明显;另外,关岭县的各类石漠化治理工程取得了显著的成果,约1/3的处于稳定和得到改善的石漠化土地是通过治理工程来实现的。本文查明了土地利用类型、人口及石漠化治理工程与石漠化演化的关系,研究结果可为石漠化治理与生态恢复工作提供科学的依据。

Based on land rocky desertification and land use data (scale: 1:50000) in 2004, the distribution law of land use types with different lithologies and occurrence ratios of rocky desertification relating to different land use types in typical fengcong (peak cluster) rocky desertified area located in central-southern part of Panxian county of Guizhou province were researched quantitatively. The results indicate that there is a high ratio of difficult to use land with exposed basement rocks in homogenous limestone, limestone interbedded with clastic rock, mixed dolomite/limestone assemblages. There is relationship among different grades of rocky desertification and land use types and rock types, such as the cultivated land on slopes has a higher occurrence ratio of slight rocky desertification in homogenous limestone, and then the limestone interbedded with clastic rock. Slight rocky desertified land was dominated by shrub land, and sloping cropland accounts for 11.67%, moderate rocky desertification was dominated by moderate coverage grass slopes, intense rocky desertification was dominated by rocky dryland which is difficult to use. From 1995 to 2000, the rate of intense and highly intense rocky desertification in moderate coverage grass slopes and difficult to use land increased. Finally, the further classification of rocky desertified land by land cover was made according to the above-mentioned researches, and the forming processes and taming emphases of karst rocky desertification in the study area was also pointed out in this paper.

In this paper the spatial-temporal evolution processes of KRD land in Guizhou Province was analyzed mathematically by using 1:100000 scale digital-distribution maps of KRD land obtained by user-computer interactive interpreting method from Landsat images in 1986, 1995 and 2000. The following conclusions are obtained: (1) From 1986 to 2000, the change in total area of KRD land in Guizhou was not obvious, but the mutual transformation of different KRD types is extremely remarkable. (2) The change patterns of KRD land are divided into three kinds: simple change mode, continuous change mode and returned change mode, and characterized by continuous change mode. (3) The forward and reversion evolution processes coexist, with the ratio of the former to the latter being 82.29%, demonstrating that the situation is getting better partially and on the whole it is worsening. (4) The rate of the KRD evolution is 398.31 km² per year, and the change rate of different type KRD land is inverse proportion to its degree of degradation. (5) The change frequencies of moderate and potential KRD land is highest and obviously higher than that of light KRD land. The regional characteristics of KRD spatial evolution and its influencing factors are analyzed, and some suggestions on comprehensive control of KRD land are put forward.