我国南方岩溶山区石漠化基本问题研究进展

通过参考国内研究的相关文献,运用比较分析方法,从岩溶石漠化概念的内涵、分布格局和量化分级、成因分析和演化过程、综合治理和效益评价等基本问题回顾了我国南方岩溶山区石漠化研究进展:岩溶石漠化的概念和成因已取得了较为一致的认识;石漠化等级评价指标相差甚远,需要建立统一调查研究方法、分级标准和评价指标体系;已探索出了一些较好的治理模式和方法,但治理建设仍然存在很大困难;目前没有成熟的石漠化治理效益评价体系和方法,严重影响了石漠化治理措施的修订和完善。指出了我国岩溶石漠化问题研究应从如下几方面加强:不断创新岩溶石漠化的研究方法;把握岩溶石漠化与人类活动相互作用关系;深入开展岩溶石漠化过程模拟与调控研究;推广和完善岩溶石漠化综合治理技术和模式;重视地球系统科学在岩溶石漠化研究中的运用。在岩溶石漠化与人类活动相互作用关系方面,特别要注意加强石漠化地区土地的生产力和人口承载力的定量研究;实施岩溶山区人类经济活动影响预报和经济社会后果预报,建立岩溶山区生态安全监控预警系统;加强不同时空尺度下岩溶石漠化人文驱动机制研究;确定自然因素和人文作用对石漠化过程的正负面影响和各自的贡献率,建立相应的概念模型和数学模型等。      

西南石漠化区林下土壤养分特征及差异性

文章采用文献检索法收集20世纪90年代以来石漠化区植被修复和土壤研究相关论文,以全国二次土壤普查养分分级标准为基础,探讨林下土壤养分改良情况及土壤化学计量特征。结果表明：（1）中国西南石漠化区林下土壤总有机碳、全氮均值均高于全国二次土壤普查养分一等级,全磷处于二级范围,土壤养分改善效果明显,而全钾含量属于五级低钾区;（2）广西壮族自治区总有机碳和全氮均值为五省（区、市）第一,全磷和全钾位于二等级和四等级,土壤养分含量增加最明显;贵州省总有机碳、全氮高于一等级34%和37%,全磷值在二等级范围,全钾值位于第五等级,贵州省石漠化林下土壤养分改良明显;云南省总有机碳、全磷指标分别高于一等级9%、21%,全氮属于二等级,全钾属于五等级,土壤养分指标有不同程度提高;重庆市总有机碳高于一等级1.75%,全氮和全磷属于二等级,全钾为五省中最高且属于四级,土壤养分指标改良较其他三省慢;湖南省总有机碳指标为二等级,全氮、全磷、全钾值分别属于二等级、五等级、五等级,湖南省需加强石漠化治理的力度;（3）西南石漠化区土壤总有机碳和全氮指标呈正相关,植被生长亦受钾元素限制。其中,广西壮族自治区总有机碳、全氮和全磷存储快,土壤改良效益极其显著;贵州省土壤固碳能力高于全国平均值;云南省石漠化地区土壤钾元素偏低,影响植被生长;重庆市土壤中全钾含量高与总有机碳、全氮、全磷关系不大,氮元素成为限制植物生长的元素;湖南省植被生长需补充磷、钾元素。西南石漠化区植被生长应充分补充钾元素,除此之外,湖南、重庆需加强磷、氮元素的补充;云南、湖南、重庆应借鉴广西壮族自治区生态修复经验,加强石漠化生态治理并发挥效益。     

Relationships between rocky desertification and spatial pattern of land use in typical karst area,Southwest China

Karst rocky desertification is a typical type of land degradation in the Southwest China. An attempt was made to study quantitatively the relationships between rocky desertification and spatial pattern of land use through applying spatial analysis of Geographical Information System in Nandong underground river system, a typical karst area, Southwest China. The spatial distribution of rocky desertification and spatial pattern of land use were obtained from interpreting Landsat Images in Nandong area in 2007 by supervised classifications, and verified and rectified through field survey. The results indicate that: (1) the total land deserted area covers 378.3 km², or 23.4% of the total area, of which intense, moderate and slight rocky desertification covers 269.46, 54.2, and 54.63 km², respectively, in Nandong area. (2) There is an obvious effect of spatial pattern of land use on rocky desertification. With the increase of elevation and slope, there is a higher occurrence ratio of rocky desertification in the cultivated land and grass land. Also, more than half of total rocky desertification was dominated within the areas of 4 km from the construction land, and 97% of total rocky desertification was dominated within the areas of 10 km from the construction land in Nandong area. And what can be known from the data is that the primary effect distance of human on rocky desertification from the construction land is 4 km, and the farthest effect distance of human on rocky desertification from the construction land is 10 km in Nandong area.     

Temporal and spatial changes of karst rocky desertification in ecological reconstruction region of Southwest China

Karst rocky desertification (KRD), as a process of soil degradation, is a limiting factor on enhancing the life condition of people in Southwest China. Fortunately, Chinese governments at different levels had taken it seriously, and the ‘Green for Grain’ program was initiated to treat and protect the fragile environment. In order to assess the dynamic change of KRD and improve the treatment of it in the future, Pingguo County, one of the ‘one hundred typical counties for karst rocky desertification control in China,’ was chosen as the study area. The results indicated that the evolution process of KRD landforms in the county might be divided into two phases: degradation phase (1994–2001) and ecological reconstruction phase (2001–2009). In the degradation phase, the area of non-KRD landform decreased from 1,132.02 km² in 1994 to 1,056.42 km² in 2001. In this phase, the area of non-KRD landform lost 5.51 % to KRD landforms, which mainly transferred to slight KRD landform with an area of 35.55 km² counting for 3.14 %. In another hand, the area of non-KRD gained 27.85 km², mainly from the slight KRD landform. As a result the area of non-KRD was reduced, meaning that the evolution of KRD became serious. In this phrase, the dynamic change degree of the slight KRD landform was the minimum, and the area of it was the largest among the three KRD landforms. Therefore, transition of slight KRD landform was the main transition type in this phase. The area of slight KRD landforms increased 38.77 km² in the county, which mostly took place in the middle and southwest karst regions. In ecological reconstruction phase, the area of non-KRD landform increased to 1,091.90 km² in 2009. In this phase, non-KRD landform gained an area of 22.82 km² and lost an area of 26.73 km², major of which from or to the slight KRD landform. Therefore, the area of non-KRD landform was increased, implying that the evolution of KRD became alleviated. In this phase, transition of slight KRD landform was also the dominant transition type. The decreased area of slight KRD landform was the largest among severe, moderate and slight KRD cases in the southwest karst region, where the ecological reconstruction projects were initiated. The efficient degrees of KRD landforms in southwest karst region were the largest in the four karst regions in this county. This study results may provide a consultant for rocky desertification control and ecological restoration in the future.     

西南喀斯特地区石漠化综合治理:成效、问题与对策

西南喀斯特地区石漠化与贫困问题相互交织,是该区域社会经济可持续发展的瓶颈。近二十年来,通过实施植被恢复、水土保持、生态移民等一系列治理措施,石漠化整体扩展的趋势得到初步遏制,由过去持续扩展转变为净减少,西南喀斯特地区生态状况呈良性发展态势,但防治形势仍很严峻,迫切需要寓经济发展于生态治理之中。本文在分析石漠化综合治理成效、存在问题的基础上,探讨了基于民生改善的石漠化防治对策。认为今后应在系统梳理和总结一期治理经验和不足的基础上,进一步加强石漠化演变规律及其关键驱动因子、喀斯特关键带结构与功能变化、植被与水文过程相互作用等基础研究,将植被恢复与生态服务提升、民生改善有机结合,健全“造血”功能,培育和发展与生态治理方向相适应的生态衍生产业,助力扶贫攻坚,实现生态治理与脱贫致富双赢,促进该区域社会经济协同发展及西南生态安全屏障建设。      

峰丛洼地区石漠化治理的碳汇研究进展

根据峰丛洼地区石漠化治理碳汇的现有研究文献,系统总结了峰丛洼地区石漠化治理过程中的碳储量空间格局及其动态过程、不同模式下的碳汇评价与定量化等方面的研究进展与不足,提出了峰丛洼地区二期石漠化治理应关注碳汇稳定性、受气候变化制约等问题,从而优化资源配置的思路;展望了峰丛洼地区二期石漠化治理工程中碳汇研究的趋势：一方面,将土壤分布格局、碳汇耦合机理研究和增加当地经济效益相结合,提高当地农民参与石漠化治理的积极性,推广和发展第一期石漠化治理工程的成果和经验; 另一方面,将遥感技术与石漠化治理碳汇研究相结合,构建更多碳汇估算模型,为二期石漠化治理碳汇定量化服务。     

喀斯特石漠化地区土壤Fe组成及其发生学意义

土壤中氧化铁的组成反映了土壤的成土过程和环境条件。通过对西南喀斯特石漠化地区不同石漠化阶段山地自然土壤和农田土壤Fe组成的分析,研究了土壤全铁、游离氧化铁和非晶形氧化铁的分布规律,探讨了喀斯特地区石漠化土壤的发育过程和Fe的指示作用。研究表明:①喀斯特地区土壤表层全铁含量在38.9～53.9g/kg之间,游离氧化铁含量在18.0～26.7g/kg之间,铁游离度在44.1%～73.4%之间,铁活度在7.2%～11.4%之间。②随着石漠化程度的加剧,土壤游离氧化铁和铁游离度呈增加的趋势,而铁活度呈降低的趋势。③在土体分布上,自然土壤剖面随深度的增加,土壤铁游离度和铁活度呈明显降低的趋势,而农田土壤铁游离度呈增加的趋势。④喀斯特地区的土壤是石灰岩溶蚀风化的产物,人为活动干扰下的自然土壤石漠化过程是在水力作用下的表土侵蚀过程,而农田土壤受水分垂直运动的影响,是土壤丢失的过程。     

西南岩溶区水土流失与石漠化的变化关系研究——以重庆南川岩溶区为例

以重庆南川区为例,利用TM遥感影像、Arcgis和Erdas软件,运用地图代数原理,采用图像数据转移矩阵计算,结果表明从1988年到2000年水土流失增强面积为9 605.89 hm2,减弱面积为79 947.85 hm2;石漠化强度增强面积为15 078.92 hm2,减弱面积为12 492.53 hm2。石漠化是水土流失长期作用的结果,水土流失是石漠化形成过程的阶段性表现,二者在成因上存在因果关系,但在生态治理恢复的过程中,水土流失减弱面积与石漠化减弱面积的变化不同步,在时间上存在滞后关系。造成这种滞后的现象,原因是石漠化土地生态的恢复过程较水土流失土地的长。      

Relationship between karst rocky desertification and its distance to roadways in a typical karst area of Southwest China

The presence and conditions of roadways determine the utilization of natural resources, which exert direct and indirect influences on karst rocky desertification (KRD) in undeveloped karst areas. This paper addresses the relationship between KRD and its distance to roadways in Pingguo County, a typical peak-cluster depression area in Guangxi Zhuang Autonomous Region in Southwest China, focusing on the three time periods of 1994, 2001, and 2009. KRD maps for each time period were interpreted by using remote sensing and GIS technology in buffer zones, which are 4.0 km wide and subdivided into eight strips of 0.5 km wide each. They are located alongside various classes of roadways, namely trunk, town, village, and unpaved roadways. Results demonstrate that slight KRD is the major type in buffer strips on both sides of roadways, which tends to decrease with an increase in distance to road baseline. In contrast, moderate and severe KRD cases cover relatively limited areas, which tend to change less rapidly. Moreover, these two KRD cases are less related to their distance to trunk and town roadways than to village and unpaved roadways. Therefore, the distance to roadways affects slight KRD distribution more than moderate and severe KRD. Temporal KRD patterns indicate that slight, moderate, and severe KRD areas alongside all roadway classes have comparatively similar trends in the periods of 1994, 2001, and 2009 KRD areas alongside various classes of roadways in the three periods (except some of those alongside the town and trunk roads) rank as follows from highest to lowest, 2001, 2009, and 1994. However, the total area in town and trunk roads is relatively small and varies little with distance from strip-to-road. KRD alongside various roadway classes is affected jointly by historical policy, distance to roadways, and landscape.     

Soil erosion monitoring and its implication in a limestone land suffering from rocky desertification in the Huajiang Canyon, Guizhou, Southwest China

Over the past decades, the vast limestone mountain areas in southwestern China have suffered greatly from karst rocky desertification (KRD), which is a unique type of desertification caused by irrational land-use practices and has drawn increasing attention of international academic community. Characterizing soil erosion in this region is the key to understanding the escalating KRD problem and finding solution to it. The authors applied leveling method to study soil erosion process in the Huajiang Karst Canyon area between 1999 and 2003, and tried to relate it to KRD expansion. The monitoring data indicate that soil in the study area was losing at an alarming rate, which is much higher than soil formation rate and has already resulted in severe KRD problem. Soil loss under different land-use conditions varied greatly during the monitoring period. The highest soil erosion rate occurred in bare and newly abandoned cropland, followed by sparse grass land, forest land, and dense grass land. In addition, soil erosion could be significantly different under different micro-topographic conditions. Because soil erosion rate in the studied karst mountain areas is surprisingly high, it is urgent to take quick actions to fight against the ongoing KRD problems in Southwest China before an irreversible situation occurs. However, the traditional way to combat KRD by abandoning current cropland needs to be carefully reconsidered, since a bare newly abandoned cropland may suffer more from rapid soil loss than before.     

西南喀斯特山地水土流失特点及有关石漠化的几个科学问题

由于特殊的岩土组构,喀斯特坡地的水土流失具有如下特点:地表和地下流失相互叠加;地表产流、产沙少;纯碳酸盐岩区地下流失比例大。论文区别了石漠化和石质化的科学内涵,指出了喀斯特山地石漠化的核心是土地的石质化,提出了按照地面物质组成与裸岩率叠加的石漠化分类系统。根据土壤中硅酸盐矿物的物质平衡,提出了不同碎屑岩含量碳酸盐岩区的土壤允许流失量介于5～500 t/(km2?a)之间。喀斯特坡地土壤虽然肥沃,但总量太少,矿质养分不足可能是石质坡地植物生产力低的重要原因。此外,根据农耕驱动土地石质化的机制,提出了相应的石漠化治理的对策建议,具体是:（1）不但要治标,提高植被覆盖率,更要治本,防止或减缓土地石质化,同时还要增加群众收入;（2）按照坡地岩土组成的垂直分带特点,因地（土）制宜,开展治理;（3）重视矿质肥料的施用;（4）在纯碳酸盐岩土石质和石质坡地农田的小型蓄水工程修建中,要加强集流面建设。      

基于Logistic-CA-Markov模型的石漠化空间变化规律研究

为了揭示岩溶地区石漠化发生、发展的一般规律,文章以贵州省六枝特区为例,获取了1990、2000、2010年石漠化数据。利用Logistic-CA-Markov模型探讨石漠化发生的驱动因子及各类型间的转移情况,并在两种情景模式下对研究区2020年石漠化空间分布进行模拟。结果表明:（1）利用Logistic模型回归分析石漠化驱动因子,能够较好的反映其分布状况,CA-Markov耦合模型模拟石漠化空间分布,精度达到理论要求。（2)无石漠化、潜在石漠化、轻度石漠化、中度石漠化演变过程中受人为因素影响大于自然因素,而强度和极强度石漠化则相反。（3）在现有石漠化演化速率情景下,各等级石漠化的演变轨迹为修复与恶化并存模式,最突出的是潜在和轻度石漠化。（4）在喀斯特山地生态产业修复和封山育林结合情景下,石漠化修复与恶化并存的双重轨迹模式改为以修复为主的单一轨迹模式,其中轻度和中度石漠化治理效果最为突出。因此石漠化治理措施重点应针对轻度和中度石漠化分布区,注重协调人地矛盾,防止利用过程中返回式演变。      

云南省石漠化调查及治理综述

经过全面调查,查明了云南石漠化分布、成因及资源环境条件。通过统一规划,多方协作,采取生物、工程、经济、社会建设等多方面的措施开展石漠化综合治理,取得了一定成效,遥感监测石漠化面积减少6.2 万hm2。其中,国土资源部门进行的地下水开发、土地及矿山地质环境整治、地质旅游资源开发等综合治理工作,消除或削弱了造成石漠化的自然或人为因素,标本兼治的效果突出。石漠化治理工作中的问题,主要有石漠化治理仍限于治点,区域面貌改观不大;考虑岩溶流域的系统性不够,选择治理方法未考虑对流域下游的影响;重植被恢复,对于区域经济和生态功能整体修复的考虑不足;调查变化情况监测手段落后,治理效果及动态不清;地下水资源的科学开发利用和依法管控尚待加强;部门之间协调整合不够,影响综合治理成效等。因此云南的石漠化治理任重道远,尚需做好第二期综合治理规划,采取有效措施,加大规划的执行力度。      

Variations of nutrient element contents of plants and soils in the process of karst rocky desertification

The present research on karst rocky desertification is mainly focused on qualitative analysis and obviously lack of quantitative and successive mechanism studies. Currently, classification of rocky desertification grades mainly depends on ratio of rocky coverage or ratio of plant and soil coverage. The process of rocky desertification was divided into latent, slight, medium and serious grades without mention of soil degradation. The Cha＇eryan catchment in the Huajiang Gorge of Guizhou Province was selected as the research area in this paper. Soil basic physical characteristics, nutrient element contents of soil and plant were studied in the process of rocky desertification. The karst soil characteristics elucidated that the clay content was high, the contents of soil organic matter, nutrient element （except potassium and sodium）, available contents of elements （except of potassium） were also high; ashes of plants were rich in calcium and nitrogen, and poor in iron, zinc, potassium and phosphorus. Meanwhile, the contents of plant ashes showed a significant positive relationship with calcium content of plant. There were no clear relations between soil degradation and succession of rocky desertification according to current classification standard. Soil particle size distribution, specific gravity, soil organic matter content, total and available nutrient element contents did not vary with the succession of rocky desertification.     

西南地区紧密背斜岩溶地下水赋存与运移特征

云、贵、川地区广泛分布紧密背斜褶曲,内部赋存大量岩溶地下水,给该地区越岭隧道建设、矿山开发等来了难题,且分布不均,开发利用难度大。通过六盘水威水背斜和华蓥市龙王洞背斜岩溶地下水赋存和径流特征的剖析,了解西南地区紧密背斜岩溶地下水赋存和运移的一般规律,为穿越工程水文地质条件分析提供借鉴,也为西南地区水资源开发提供一定的依据。     

重度石漠化区不同土地利用方式下土壤养分特征

本文以云南省蒙自市西北勒乡碧色寨村石漠化土地为研究对象,基于主成分分析法（PCA）研究岩溶石漠化区不同土地利用方式下的土壤养分特征。结果表明:（1）研究区土壤各养分指标变异系数介于0.14~1.76,不同土地利用方式下,土壤养分状况有较大差异;（2）研究区土壤12项养分指标可归结为3个主成分,所提供的信息占全部信息的90.69%,其中PC1主要包含了全磷、有效磷、速效钾和有效锰,PC2主要综合了有机碳、全氮、全钙和有效锌,有效铁对PC3具有较大的贡献。（3）对不同用地类型土壤养分的主成分得分进行排序,由大到小依次为火龙果地>林地>封育草地>玉米地,表明植树造林及火龙果种植等方式能有效改善石漠化区的土壤养分状况。建议对样区的石漠化治理应以封山育土为前提,以生态恢复为目的,通过种植火龙果与修复林地改善样区土壤状况,逐步形成生态环境与社会经济协调发展的石漠化综合治理体系。      

西南岩溶地区植被喀斯特效应

西南岩溶地区是我国主要岩溶带之一，也是世界岩溶研究重点地区，区内因人口众多，植被破坏严重，部分地区因人为作用已经产生一系列的环境问题，本文从岩溶地区植被演替规律出发，针对不同植被生态条件，通过对比不同表层岩溶泉的水化学特征和表层土壤空气CO2（g)（表示呀以气相形式存在）的含量，分析了植被在岩溶区，特别在表层岩溶带的喀斯特效应，由此，一方面可以推动岩溶研究的进一步发展；另一方面可以提高人们的岩溶环境保护意识，从而为西南地区生态恢复提供基础资料。     

Spatio-temporal evolution of rocky desertification and its driving forces in karst areas of Northwestern Guangxi, China

Rocky desertification (RD) is a process of land degradation that often results in extensive soil erosion, bedrock exposure and considerable decrease of land productivity. The spatio-temporal evolution of RD not only reflects regional ecological environmental changes but also directly impacts regional economic and social development. The study area, Hechi, is a typical karst peak cluster depression area in southwest China. Remote sensing, geographic information systems (GIS) and statistical techniques were employed to examine the evolution, including the identification of driving forces, of karst RD in the Northwestern Guangxi. The results indicate that RD became most apparent between 1990 and 2005 when areas of various types of RD increased. Within the karst RD landscape, slight RD was identified as the matrix of the landscape while potential RD had the largest patch sizes. Extremely strong RD, with the simplest shape, was the most influenced by human activities. Overall the landscape evolved from fragmented to agglomerate within the 15-year timeframe. Land condition changes were categorized as five types; desertified, recovered, unchanged, worsened, and alleviated land. The largest turnover within the RD landscape was between slight and moderate RD. With regards to the driving forces all RD had been increasingly influenced by human activities (i.e., the stronger the RD, the stronger the intensity of human disturbances). Dominant impact factors of the RD landscape had shifted from town influence and bare rock land in 1990 to bare rock and grassland in 2005. Moreover, the impacts of stony soil, mountainous proportion and river density on RD increased over time, while that of others decreased. The significant factors included human activities, land use, soil types, environmental geology, and topography. However, only anthropogenic factors (human activities and land use) were reported as leading factors whereas the others acted simply as constraining factors.     

The relations between land use and karst rocky desertification in a typical karst area,China

Karst rocky desertification (KRD) is one major type of desertification which is under irrational human impact on the vulnerable eco-geo-environment. In this study, Zhudong fengcong rocky desertification landscape was selected to investigate the land use types distribution law in different rock types and the KRD land in different land use types. KRD data was determined by user–computer interactive interpreting method from Aster images in 2004, according to the exposed ratio of rock, the coverage of vegetation and soil in 0.2 km² unit, integrating with land utilizing present situation map, hydrogeology map, relief map, vegetation map, soil distribution map, as well as the practical investigation and the population census datum in 2002. Results showed that the occurrence ratio of KRD land is different in land use types and rocky assemblages obviously; land cover has a strong impact upon KRD. The sloping cropland distributed in homogenous limestone has a higher occurrence ratio of light KRD, secondly, is in the limestone interbedded with clastic rock. Light KRD land was dominated by shrubland, and sloping cropland accounts for 11.67% of it, moderate KRD land was dominated by moderate coverage grass slopes, strong and extremely strong KRD was dominated by rocky dry land which is difficult to use.     

岩溶断陷盆地“盆-山”耦合地形影响下的气候特征及其对石漠化生态恢复的影响探讨

掌握石漠化山区受海拔影响的气候特征的垂直差异,能够对岩溶山地气候及其影响下的水热组合条件有更为科学的认识,对石漠化演变研究和综合治理有重要意义。本文通过在典型石漠化山区（云南蒙自断陷盆地区）沿盆地、坡地到山区设立三个小型气象观测站获取山地垂直剖面的气象数据,从月（季）、日尺度分析石漠化山区“盆-山”耦合地形的气候垂直特征及其对石漠化生态恢复的可能影响,结果表明:（1）观测剖面是当地主导风东南风的背风坡,年降雨量高原面（1 027.4 mm）>盆地（662.6 mm）>坡面（574.4 mm）;且 “山谷风”效应显著,白天吹谷风,降雨比例更大。地形起伏使盆地降雨年变异系数达152.36%,远大于坡面（113.81%）与高原面（99.36%）,地形放大了垂直方向的“干湿”差异,区域干燥指数:盆地（1.74）>坡面（1.70）>高原面（0.88）。（2）垂直方向水汽差异使高原面年太阳辐射量（5 492 MJ·m-2）略小于盆地（5 817 MJ·m-2）。同时盆地与高原面气温垂直梯度达0.74 ℃·100 m-1,因此在光热条上存在明显的垂直差异。（3）垂直气候特征对石漠化生态恢复的影响具体表现在:①年内降雨集中,结合坡度较陡的地形易加速水土流失;②降雨量少,且集中在日间,强烈的蒸发易加剧土壤水分亏缺,不利于植被恢复。③研究区水分缺乏,因此在植被恢复治理中应选择耐旱的作物,同时要考虑垂直方向的光热条件差异,盆地选择喜光热作物,海拔高的地区选择喜温凉的作物。