Restoring Reclaimed Land To Forests Or Grasses And Approaches To Vegetation Reconstruction In Northwest China

Based on reviewed literatures and collected data on environment change, population, resource, agriculture and agricultural economic development level, patterns of vegetation reconstruction in northwest China, on natural environment conditions and technical measures on which efforts in artificially reconstructing vegetation rely, and on vegetation succession,籶rinciples of restoring reclaimed land to forests or grasses (RRF) on fragile sites of ecological environment (EE) in northwest area were expounded. Theories and techniques as well as middle and long-time demands for research were analyzed and summarized. It is first time that the concept on function zones and units is put forward, which makes sense for practice of RRF in northwestern area. Supporting and limitation degree of natural environment, population, economic development level on RRF is clarified after an analysis of basis of physical environment and social economic conditions. Necessity, feasibility and prospect of RRF and reconstruction of vegetation were expounded after an analysis of environment change, present situation. It also first time that zones of RRF-types in northwestern area were classified according to laws of physical differentiation. Particularities and approaches to RRF were expounded and suitable patterns of structure for different sub-zones and general patterns for the entire zone were pointed out. Questions to which attention should be paid during RRF-efforts were discussed at a view of policies, investment, human power, control system and of experiences and lessons from reconstructing vegetation in northwestern area.1. It is pointed out that (1) much attention should be paid to the mixture patterns of grass and trees; (2) unification of "Benefits for others" and "Benefits for selves" should be emphasized; (3) market's regulatory functions should be efficiently exerted; (4) priority of RRF should be arranged according to suitability of farmlands for forests or grasses, (5) priority of application of various models of pattern should be determined according to suitability of plant communities; (6)principle of "site adapted reconstruction of vegetation" should be strictly implemented, that is: seeking for truth, adapting for local sites, reforestating if it is suitable for trees, reconstructing with grass if grass is the best adapted landscape, leaving without any treatment if neither forest nor grass can establish; (7) principles of "coordinating and unifying ecological and economic targets" should be kept; (8)and optimal planning of ecological economic systems should be followed.2. Present urgent problems for RRF in northwestern areas are put forward: (l)overall plan on scientific research; (2) relationship between physical environment basis in northwestern area and RRF; (3) study on environment in northwestern area and change of original vegetation (4) Suitable forest and grass types and approaches to RRF of various zones in northwestern area. (5) Security measures for RRF in northwestern area (6) Assembly, matching and extension of advanced, practical research results; (7) study on and implementation of compensation mechanism for ecological benefits.3. Research emphasis on EE and RRF in this area is recommended: (1) take notice of studies on relationship between RRF in northwestern areas and strategic restructure of agriculture. (2)take attention to studies on necessity and urgency of realization of large key ecological projects as pioneer of RRF programs in some fragile ecosystems (3) take notice to study on effects of various physical environment conditions, economy, resources, market development on RRF (4) study on influence extent of international markets on agriculture in these areas after WTO, and their follow-up positive and negative effects on RRF and ecological environment construction (EEC); (5) pay attention to study roles of science and technology on EEC in northwestern area, particular attention to research, extension and application of techniques on EEC and RRF.4. Emphasis of future research...