Irrational Land Use Research Articles

Modelling nutrient retention function of ecosystem – a case study in Baoxing County, China

Non-point source pollution is one of the crucial causes leading to degradation of rivers and lake water quality; therefore, it has been studied in depth worldwide. However, few studies exploring the effect of terrestrial ecosystem nutrient retention function on water quality have been conducted to date. Natural ecosystems such as forests and grassland can hold runoff and sediment, thereby reducing the nutrients entering nearby aquatic systems, which is very important to improving water quality. Based on the landscape source-sink theory, this study assessed the nutrient retention function of ecosystems. The results showed that terrestrial ecosystems retained 78% of the Total Nitrogen (TN) within the system, thereby significantly reducing the TN entering the water. The nutrient retention function of different ecosystems varied significantly. Forests had the greatest potential capacity to maintain TN, but the actual retained TN was only about 10% of that applied to cropland. Because of irrational land use patterns, the potential forest intercepting nutrient function was not fully utilized. Specifically, nutrient retention function varied with altitude and slope. When the altitude was in the range of 1000 m or between 4000 m and 4500 m, the highest function could be attained, resulting to increases or decreases between regions. The nutrient retention function decreased as slope increased. The critical source area (CSA) was primarily distributed along the river bank. However, the critical sink area which made a high contribution to nutrient reduction did not appear that similar distribution like CSA. The critical sink area scatted in the whole basin mainly and only overlapped with the critical source areas in some place.

English

  Low vegetation coverage and irrational land use are regarded as two main factors influencing soil loss. In order to improve vegetation recovery and to adjust land use pattern on the Loess Plateau, the data of precipitation, net primary productivity of vegetation, and eco-water requirement of main crops of key counties on the Loess Plateau are used in this paper. The concepts of utilization/adaptation capability of eco-water requirement are used and plotted against mean annual precipitation inthe 1960s to 1990s for vegetation and crops, respectively. Results demonstrate that in the regions with lower than 400, 400 to 510 and over 510 mm precipitation, the grass/shrub, grass/shrub/forest and forest fit to be planted, respectively. For crops in the regions with less than 300, > 310, > 450 and > 510 mm precipitation,Kaoliang and glutinous, millet, winter wheat, and maize are satisfied, respectively.   Key words: Loess Plateau, vegetation, crops, adaptation capacity eco-water requirement.

The role of policies in land use/cover change since the 1970s in ecologically fragile karst areas of Southwest China: A case study on the Maotiaohe watershed

Study of land use/cover change and its driving forces is one of the most significant fields in global environmental change research. Karst land is a type of important and unique terrain on the Earth's surface because of its extensive distribution, impressive landforms, and high ecological fragility. Recently, more and more researchers have realized that irrational land use practices are leading to a series of alarming environmental issues including rocky desertification in karst areas. Studies on land use/cover change and its driving forces in karst areas are significant in achieving regional ecological construction and sustainable development. Policy has long been considered as one of the major driving forces at national level for land use/cover change. In mainland China, designated and in-depth study on the interaction between land use/cover change and relevant policies is still very limited. Through an integrated technique of geographic information system (GIS), remote sensing (RS), and global positioning system (GPS), the authors attempted to address this issue by using the Maotiaohe watershed in Guizhou province in southwestern China as a case to examine its land use/cover change patterns, and the roles of policies in land use, agriculture, forestry, and eco-environmental protection from 1973 to 2007. The study indicated that land policies contributed largely to the increase of arable land in the 1980s, and helped prevent it from decreasing at the fringe of cities and towns since the 1990s; agricultural policies played active roles in the change of water area and indirectly contributed to the change of construction land. The forestry and eco-environmental policies were found to be the main reasons for the consistent increase of forest land since the 1980s and for the decrease of arable land and rocky desertification land since the 1990s.

Climatic and anthropogenic drivers of land use/cover change in fragile karst areas of southwest China since the early 1970s: a case study on the Maotiaohe watershed

Land use/cover change and its driving forces has been one of the most important fields in global environmental change research since the 1990s. Karst areas are distributed extensively on the Earth’s surface and are usually characterized by a fragile eco-environment. In southwest China, karst landforms are fully developed and their eco-environment is highly fragile. Over the past decades, irrational land use practice has caused a series of alarming eco-environmental issues including forest clearing, soil erosion, and karst rocky desertification. Therefore, it is of great practical significance to study land use/cover change in this area and its driving forces in order to re-build the damaged eco-environment and achieve sustainable land use. In this paper, the authors conduct a case study on land use/cover change and its natural and human driving forces since the early 1970s in southwest China’s Maotiaohe watershed. The results indicate that the land use/cover pattern in the study area has undergone a very complex change, which is a result of combined action of both natural and anthropological factors. In the 1970s and 1980s, climate change and fast population increase played dominating roles in the change of arable land, shrub land, grassland, and rocky desertification land. Since the early 1990s, economic development has gradually taken the place of population change to become the overwhelming human factor to go along with climate change in driving the land use/cover change, particularly the change in arable land, construction land, and rocky desertification land.

Land-use planning of Minoo Island, Iran, towards sustainable land-use management

Land-use planning is one aspect of sustainable development that determines the integrity of socioeconomic and ecological nuance. Land evaluation is an approach to sustainable land-use planning, which predicts the capability of the land-use system. This means that a specific land area should be under specific use, considering certain factors and characteristics of the land and its location. In other words, lack of proper information on land capability and rational and irrational use of land leads to destruction of land resources. This paper discusses the findings of ecological and socioeconomic resource issues for Minoo Island and the surrounded zone. The study covers an area of about 172km2 in southwest Iran. To establish environmental unit maps, digital layer maps of the soil texture were overlapped. The study empirically established that the area has the capability to accommodate ‘levels two’ urban and industrial development. Moreover, Minoo Island is considered to have potential for conservation and ecotourism, with a 60% potentiality for dryland farming.

Sustainable land-use patterns for arid lands: A case study in the northern slope areas of the Tianshan Mountains

Sustainable land use patterns are ecological and economic prerequisites of regional sustainable development. This is especially true for arid lands, where the environment is wholly fragile thanks to extremely limited precipitation, and where human activities have greatly transformed natural desert system by clearing natural vegetation, expanding oases and even building dams on inland rivers. However, the current studies on land use patterns are still characterized by field investigations and case studies, with almost no solid scientific basis. This paper holds that land types and their combination patterns are the principal basis for designing sustainable land use patterns, and that GIS and RS-based large-scale land type mapping and the study of their spatial combination structures should be coordinated with the demand of social development. The existing environmental problems induced by irrational land use mostly result from their deviation from the natural properties of land types. Taking the northern slope of the Tianshan Mountains (NSTM) as an example and considering land type patterns as the basis of land use patterns, this paper improves the vertical oasis- and-mid-mountain two-belts development model and the sustainable mountain land use model for arid lands put forward in recent years; and in terms of oases patterns, it outlines oasis development models, including intensive land use pattern in alluvial-diluvial fans, moderate agricultural development pattern in alluvial plains, and ecological land use pattern in river-end oases.

Spatial-temporal change of landscape pattern in the distribution region of endemic species Tetraena mongolica Maxim.on Ordos Plateau

Using the technology of remote sensing,geographical information system and the analysis software of landscape pattern,the paper analyzed four sensing images of Tetraena mongolica distribution region in different periods(1977,1990,2000,2005) to study the dynamic changes of temporal and spatial landscape patterns based on the images interpretation and landscape classification and cartography and the calculation of landscape index,The results show:(1) On landscape scale,patch number,landshape index,Shannon's diversity index and Shannon's evenness index were increased,while mean patch size and dominance index were decreased year after year.It is indicated that the landscape pattern tended to be fragmented,landscape components tended to be complicated in the distribution region of T.mongolica.(2) In the different habitats of Tetraena mongolica the landscape patterns in Shizuishan,Taositu,Qianlishan and Wuda populations were fragmented.The landscape structure tended to be diversified and complicated.While the landscape patterns in Wujiamiao,Qipanjing and Hainan populations were relatively integrated because of less severe human driving force.And there were preponderant patches connected each other in the landscape.(3) Of all of the landscape types,T.mongolica was the maximal landscape component and basic landscape type in the research region,but its dominant status was reduced in the 28-year period of and its distribution tended to be dispersed and fragmented.Besides the land for industrial,urban construction and farming purposes as well as desertified land and other vegetations were largely increased and tended to be connected.Their functions in the landscape were increasing gradually.(4) It is indicated that the industrial development and rapid urbanization and land desertification caused by irrational land use were direct reasons for the T.mongolica population area reduction and landscape pattern change of the research region.

Close relationship between the frangibility of mountain eco-environment and mountain disasters: A case study of Dongchuan, Kunming in Yunnan Province

Anatomical details are given in this article, which is performed by investigating the relationship between through the frangibility of mountain eco-environment and the status of irrational land-use in typical region of debris flow in Dongchuan district, Kunming city, yunnan Province. This analysis is extended to the relationship between vicissitude of mountain disasters and the frangibility of mountain environment. The relatively coupling action of a vicious circle is a evolving characteristic by debris flow sand-gravel there. The eco-security is being faced with serious challenge. The tactics of eco-security has been constructed since 1980s. Thus, the eco-environment can gradually be repaired and optimized to achieve a fine circle.

Sustainable management of grassland ecosystems for controlling Asian dusts and desertification in Asian continent and a suggestion of Eco‐Village study in China

AbstractAsian dusts, yellow sand, or dust and sand storms (DSS) in Asian continent are the end products of desertification, which became a regional environmental problem being aggravated by time. It is closely related to an issue of sustainability in the region. As the desertification is caused not only by natural factors, such as the climate change, strong wind, and low precipitation, but also by rapidly increasing human activities, such as overgrazing, misuse of water resources, and irrational land use, it is urgent to make efforts to combat desertification in Asian continent including China. In this regard, it is necessary to consider socio‐economic aspects as well as ecological aspects and, consequently, the project for the construction of a Demonstration Model Village for eco‐environmental rehabilitation should be paid to a special attention. The authors deal with this regional issue in consideration of three Es, which are represented by ecology, economy, and environment in providing the perspectives in sound approach to the issue. As an approach to the issue of Asian dusts and desertification in Asian continent, this Eco‐Village study provides one way forward.

Landscape change and sandy desertification in arid areas: a case study in the Zhangye Region of Gansu Province, China

The Zhangye Region of Gansu Province is an important agricultural base in arid northwestern China. During the twentieth century, especially in the last five decades, the region has experienced sandy desertification. To document the status and causes of this deterioration, satellite images, meteorological and socioeconomic data to assess landscape change from 1993 to 2002 were interpreted and analyzed. The results show that during the intervening 9-year period the area of sandy lands has increased by 642.2 km2, which consist of aeolian sand dune (357.1 km2) and potential sandy land (216.3 km2). Although the development and reversion of sandy desertification co-exist, the sandy desertification in this area seems serious and is attributable to the irrational use of water and land.

Causes of wetland degradation and ecological restoration in the Yellow River Delta Region

Yellow River delta (YRD) is one of the biggest deltas that there is a large area of wetland in the world. Thanks to soil (sands) sediment carried by the Yellow River, there was averagely the newly formed land 21.3 km2 in YRD. During the development of petroleum industry and urban expansion, wetlands were degraded due to population growth, irrational land use, in addition to adverse natural eco-environment such as lower precipitation, higher soil evaporation and soil salinazation. The major ecological measures to restore degraded wetland concerned with ensuring water supply, especially establishing perfect irrigation works; protecting virgin plant communities and assisting them to regenerate by the way of site preparation, improving living surroundings; introducing salt-tolerant plants to increase vegetation species and plant coverage, thereby enhancing the capability of wetland to combat contamination and pollution through plant remediation, uptake, absorption, etc. Finally making a comprehensive land use plan, accordingly removing deleterious facilities.

How types of carbonate rock assemblages constrain the distribution of karst rocky desertified land in Guizhou Province, PR China: phenomena and mechanisms

AbstractIn southwestern China karst rocky desertification (a process of land degradation involving serious soil erosion, extensive exposure of basement rocks, drastic decrease of soil productivity and the appearance of a desert‐like landscape) results from irrational land use on the fragile, thin karst soil. Soil particles in the Guizhou karst plateau were accumulated predominantly from residues left behind after the dissolution of carbonate rocks, and the thickness of the soil layer is related to the amount of argillaceous substances in the lost carbonate rock. This paper examines the spatial distribution of karst rocky desertified (KRD) land in Guizhou Province, and relates it to the different assemblages of basement carbonate rocks.Types of carbonate rock assemblages are discussed using a 1 : 500000 scale digital‐distribution map. Their distribution and sensitivity to erosion are analysed, demonstrating that the occurrence of KRD land is positively correlated to homogeneous carbonate rocks. Differences in physical and chemical properties of limestone and dolomite rocks lead to differences in dissolution, accumulation rate of soil particles and relief on the surface, and these factors influence land‐use potential. Copyright © 2004 John Wiley & Sons, Ltd.

Dynamics and driving factors of agricultural landscape in the semiarid hilly area of the Loess Plateau, China

Poor vegetation cover as a result of irrational land use is generally considered to be the major factor of soil erosion in the Loess Plateau in China. However, there is lack of knowledge concerning the dynamics of land use and the complex role of socio-economic policy factors in inducing changes in land use, especially at detailed scale levels such as in individual small catchments. This study analyzes the process of human-induced landscape change in a small catchment in the northern part of the Chinese Loess Plateau from 1958 to 1999. During this period, a significant reduction of the area of farmland on steeper slopes and an increase in woodland took place. Household questionnaires among the local farmers, a review of the historic events and literature allowed the assessment of socio-economic and policy forces that caused these changes. The research showed that the changes of agricultural landscape pattern are mainly the result of the dissolution of People’s Communes in 1979 (established in 1956), the introduction of a Household Responsibility System (in 1978), the implementation of the Family Planning policy (in 1978), and the adoption of a market-directed economic system (in 1992), as well as the execution of an integrated soil erosion control project (begun in 1981). The changes of the agricultural landscape show the benefits in both ecological and economic respects.

Dynamics of Species Diversity of Communities in Restoration Processes in Horqin Sandy Land

In this paper species composition and species diversity of communities with different succession times were studied in restoration processes. Our results showed that species richness is 7, 11, 17, 14, 28 and 30 in the communities, of which the succession time is 1, 3, 5, 12, 20 and 30 years, while the species diversity index is 1.458 8, 2.610 0, 3.108 4, 1.696 8, 3.738 6 and 3.639 6 respectively. For life form composition of all communities along the restoration succession series, annual herbaceous plants are dominant, but species number of perennials increases and the dominance of one species is more than that of annuals as succession proceeds. Species number of Chenopodiaceae is stable and their dominance in the community is high, especially in early successional stages. Species number of Gramineae increases continuously along the succession gradient and their importance in community also increases. Ecological dominance declines gradually, while community evenness increases progressively along with succession. In a relatively short time of 30 years the environment of sandy land shifted successfully from mobile sandy land to fixed sandy land, and species composition and community structure improved greatly. This research provided test and sample for the possibility of vegetation restoration under natural condition, as well as a practical pathway for the protection of biodiversity. The most important thing is to stop irrational use of land so that the natural ecological processes of vegetation recovery such as dispersal, inhabitation and propagation can be accomplished continually under stable environments.

Land use evaluation and scenario analysis towards sustainable planning on the Loess Plateau in China—case study in a small catchment

The Loess Plateau has been suffering from serious soil erosion for a long time, which originated in a population growth about 2000 years ago. After then, the rapid increase in human activity has led to more areas became used for grain production. Original vegetation has been destroyed and soil erosion has become more and more serious. Most research works indicate that the soil erosion on the Loess Plateau is mainly induced by irrational land use structure and low vegetation coverage. Controlling soil erosion is a significant factor in making a sustainable land use planning for the Loess Plateau. In this study, a procedure towards such a planning is presented, based on results from a research project in a small catchment on the Loess Plateau. A land suitability evaluation for rain-fed agriculture based on biophysical parameters, and a comparison between land suitability and current land use, were first carried out. Some potential land use scenarios, based on surveys on biophysical and socio-economic parameters in the catchment, and plans by the authorities, were proposed for further evaluation of their effects on soil erosion, economic feasibility and social acceptance. The scenarios were tested by (i) simulation modeling, to show the differences in erosion, and (ii) from studies on the influence of the scenarios on farmers' economy and their response. The results indicated that the following land use scenario was acceptable: all land with deep soil and slopes smaller than 15° is used for agriculture cropland, possibly combined with biological conservation measures, such as mulching combined with improved fallow, and all land with steeper slopes than 15° is used for other purposes (orchards and other cash trees, woodland, shrubland, grassland). A great reduction of on-farm income, however, would be induced on the short term by such a scenario. Local farmers will find it difficult to accept it unless financial support from external sources is available. On the long term, the scenario will be promising for both economic income improvement and soil erosion control since some production will be obtained from the conversion of cropland into orchards/cash trees (preferably on slopes 15–25°). Thus the land use modification should be carried out gradually. On the short term (5 year), it is suggested that cropland on steeper slopes than 25° is returned to woodland/shrubland/grassland while also fruit trees are planted on slopes 15–25°. Within 10 years, cropland with slopes steeper than 15° is suggested to be converted into orchard/woodland/shrubland/grassland.

The effect of land use structure on the distribution of soil nutrients in the hilly area of the Loess Plateau, China

The irrational land use is one of the main reasons for the soil erosion and nutrienloss in the loess hilly area of China. In this project, 4 types of typical land use structure of sustain ment for about 15 years in the loess hill slope are selected to study the effect of land use structure on the distribution of soil nutrients. From hill bottom to hill top, the patterns of land use types are: grassland-slope farmland-forest, slope farmland-grassland-forest, terrace-grasslandforest and slope farmland-forest-grassland. By measuring the contents of the total N, total P, available N, available P and organic matter of soils, the results show that the land use structure types of slope farmland-grassland-forest and terrace-grassland-forest have a better capacity to maintain the soil nutrients.

Anthropogenic influences on changes in the sediment load of the Yellow River, China, during the Holocene

Using data on formation of the Loess Plateau of central China, loess-palaeosol sequences, pollen analysis, historical geography, and long-term experimentation on rates of soil erosion, it is demonstrated that current serious erosion on the Loess Plateau is mainly due to human destruction of the natural vegetation and irrational land use. These two modifications greatly reduce soil-infiltration capacity and resistance of the soil to erosion. The increase of soil erosion began ca. 5000 BP at which time a hunting and pastoral life began to change gradually to a sedentary life centred around cultivation. Using the volume of Holocene loessic sediments on the continental shelf of the Bohai, Yellow, and East China Seas, it is estimated that the present sediment load of the lower Yellow River is at least three times greater than it was during the Holocene. Although human-induced soil erosion in the Loess Plateau began earlier, it was not until the Tang dynasty (about 1000 BP) that it began to increase rapidly. According to available information on projected and planned economic development and major conservancy works in the Yellow River basin over the next 25 years, it is predicted that sediment load of the lower Yellow River will be reduced by about 30-40% in the early twenty-first century.

Soil erosion and its control in the loess plateau of China

Abstract. The loess plateau in China is the most developed region of loess in the world in terms of extent, thickness and depositional sequence. It is also the region with the most serious soil erosion in the world. This paper reviews the factors and reasons for soil erosion in this area. The loess is prone to vertical cleavage and its surface soils are soft and loose. Rainstorms are frequent with intense rain concentrated during the summer. Irrational land use and exploitive management have been carried out for thousands of years and express themselves through the loss of grassland and natural forests. Finally, some soil conservation schemes for use in the loess plateau are suggested.