On Construction of Ecological Economic Forests

摘要：為鞏固退耕還林成果，實現可持續發展，規模適度地發展生態經濟林是一條重要途徑，同時隨著人民生活質量的改善，須重視無公害綠色果品的生產。本文從生態經濟學的角度，以棗樹為例，提出了生態經濟林的內涵及主要營建技術，以期為退耕還林后續產業發展提供依據。Abstract: To consolidate the results of returning cultivated land into forests and realize sustainable development， it is an important way to develop ecological economic forests at a reasonable scale. At the same time， with the improving quality of people’s lives， we must pay attention to production of pollution-free green fruits. This paper， from the point of ecological economics， takes the example of date trees for example， presenting the connotation of ecological economic forest and main construction technologies， in order to provide basis for the industrial development after returning cultivated land into forests.關鍵詞：生態經濟林；生態環境建設；綠色果品；營建技術；可持續經營Keywords: ecological economic forest， ecological environment construction， green fruit， construction technology， sustainable operationThe basic connotation of ecological economic forestsEcological economic forest， different from economic forests of general concept， features the following three basic characteristics: first， favorable for the construction of local ecological environment， meeting the basic ecological requirement for environmental construction; second， the fruits (products) meeting the requirements of green food; third， favorable for sustainable operation. Production of green fruits based on ecological economic forests is a good choice for sustainable development of ecological economic forests， and also necessary for industrial structure adjustment to overcome poverty and achieve prosperity. Green fruit requires not only free of pollution and safety， but also high quality and nutrition. Therefore， ecological economic forests must be constructed on the base of species of good quality， high nutritional value， and strong adaptability(or clone Varity). Sustainable operation is another important feature of ecological economic forest. Operation of ecological economic forests should not only consider the continuous high and stable yield from fruiting to renewing of economical trees of first generation， but also high and stable yield of successive generations， and only sustainable operation can realize sustainable development. A great number of studies at home and abroad show that planted forests especially those rapidly growing species with high requirements on fertility may lead to decline of soil fertility， and how to maintain the soil fertility becomes a concern for domestic and international forestry industry. The core of sustainable operation for ecological economic forests lies in the improvement of soil fertility and effective sustainable use of forest land. Therefore， we should adopt the following technologies and take engineering and biological measures to protect the soil， control soil erosion， increase organic and nutrient content， improve soil structure， optimize local runoff to improve soil water regime， supplement the nutrient with scientific manuring， and reduce unnecessary nutrient consumption through tree control. Make preparations for soil nutrient monitoring of for- est land， to secure the complement exceed the consumption each year， improving soil fertility gradually.Main technologies of ecological economic forestAccording to the basic connotation of ecological economic forest， under current production level， we should adopt following technologies in the construction of ecological economic forests.a. The ecological environment of forest land must conform to standards for green food， meaning the forests should have fresh air， high water quality， pollution-free soil， and is far from direct pollution of industrial enterprises， and 50 meters away from main highways， with atmosphere， water quality， soil and other indexes proved by the environmental protection department to meet production standards for green fruits. In addition， according to Opinions of the State Council on Further Doing the Trial Work Better on Returning Cropland to Forest， “in places with serious water losses and soil erosion and hazards of blown sand， gradient of 25 ° or above， source of rivers， nearby lakes and reservoirs， mountain， rocky hill lands， mountain ridges and other places of ecological importance， should return into grass or forests ecologically\"， and are not suitable for ecological economic forests.b. Species configurationThe construction of ecological economic forests should be synchronized with that of surrounding mountain shelter forests， and they should be embedded in mountain shelter forests following the patch distribution of site type in the mountain， in accord with the principle of planting right species in right areas and taking measures against specific environment， in order to provide favorable conditions for natural enemy reproduction and spread control of diseases and insect pests.c. Soil preparationLoess hilly area should use partition slope horizontal ditches for soil preparation. Along the contour line and in accordance with the terrain draw lines， to determine partition slopes and horizontal ditches. With a gradient of 15° ~ 30°， the distance between partition slopes should be 6 to 7 meters， and horizontal ditches should be 1 meter wide， and 1 meter deep， with 0.7 meter of backfilling mellow soil and 0.3 m and 0.3 meter of immature soil everted for ridging. Soil preparation should be carried out in the rainy season or autumn one year before planting， to retain maximum of the of slope surface runoff， mellow the soil and improve the water and nutrient content. During the soil preparation， we can bury three layers of weed or crop straw in the planting hole， about 10 kg in each hole. If a spring drought occurs， the buried straw and weed can help improve soil moisture content by 1.99% to 3.49%， and organic content of 0 cm to 60 cm soil by 66.67%. Taking date trees for example， partition slope horizontal ditch soil preparation method can bring a better survival rate， increment， proportion of fruiting plants， and yield than fish-scale holes.d. Forestland managementBefore rainy season， maintain the forestland， mend rat holes or man-made damages， and keep the counter-slope of ditches.e. FertilizationFertilizers used in green fruit production mainly include green manure， pollution-free farm manure， cake fertilizer and non-chemically compounded commercial fertilizers (such as humic acid， microbial fertilizer， etc.). Ecological economic forests are often constructed at hills or mountains， so it will cost much to carry fertilizers up to mountains， and crops also divert a great amount of fertilizers. How to better solve the fertilizer supply problems for ecological economic forests is important not only for current construction of economic forests， but also for economic forests in mountain areas to maintain high yield and efficiency. However， planting green manure crops is a way to supplement fertilizer supply.(1) The root distribution of green manure crops in the economic forests in down slope is much wider and denser than up slope. Plant 1 to 2 meters or so wide green manure crops one meter above the horizontal ditches can mediate local runoff of partition slopes， and the crop straw can provide nutrient supplement to forest land. Practices show that planting green manure crops in partition slopes can ease the water competition between trees and crops. Suitable green manure arbuscle include 1 indigo， caragana microphylla lam， lespedeza， etc， and suitable leguminous forage includes alfalfa， sainfoin， crown vetch， astragalus adsurgens， etc.(2) Green Manure: it is reported that green manure by burying weed or covering with grass can significantly increase the content of organic matters in the soil， by 0.53% in average， while inorganic fertilizers can not realize the same effect. Burying: in vertical direction of the horizontal ditch， dig 50 cm long， 30 cm wide and 30 cm deep grooves on both sides of a jujube tree， and bury 15 kg of green manure (fresh weight) for each tree in layers and cover with soil. Covering with grass: floor the horizontal ditches with weeds， 3 cube meters and 15 kg (fresh weight) of green manure for each tree， and cover the weed with a thin layer of soil.f. Pest control(1) Strengthening agricultural control， manual control and physical control: cover the tree trunk with grass before pests to overwinter， untie and burn the grass after entering winter; clean up the bark miners， ill and insect fruits; coat trunk with whitewash to eliminate overwintering diseases and pests. Clear up the ill or pest branches through pruning during the growth， and ease the harm of diseases and pests through pest catching and bagging fruits. Based on the sex ratio of the pests， trap and kill pests with sex attractants， sweet and sour liquid， Jiaduo Frequency-Vibrating Disinfesting Lamps， to reduce the population density.(2) Make full use of natural enemies: form a diversified ecological environment through planting green manure crops in ecological economic forests and integrating with the surrounding shelter forests， to induce natural enemies or captive feeding and introducing natural enemies， to increase the population quantity and resume the natural control ability.(3) Choose pesticides reasonably， following pesticides standards for green fruit production. In addition， minimize the usage of preservative， insecticidal fungicide， antistaling agent and so on during the storage of harvested fruits， so as to avoid the pollution， and store the fruits mainly by mechanical and physical ways such as cellar.SummaryAs mentioned above， ecological economic forests can greatly contribute to development of forestry and agriculture economy， improvements in the standard of living in rural area， increases in green fruit supply to urban and rural residents， and strengthened competitiveness in international markets. We should put more efforts in the popularizing， to fully display the role of ecological economic forest construction technologies， and then contribute to the improvement in economic and social benefits of agroforestry， and to the ecological construction and sustainable development in China.(Author: from Huangtushan Tree Farm， Hulan District， Harbin， Heilongjiang， 150524. Central Work Station of Hulan Forestry Bureau， Harbin， Heilongjiang， 150500)