| Eucalyptus afforestation has characteristics with good effect and benefit, as a result, it is widely cultivated in southern China. Moreover, it is one of the main timber species of afforestation that is promoted in:Guangxi in recent more than 20 years. However, in the process of Eucalyptus forest management, in order to pursue the economic efficiency, the short cycle operation and unscientific forestation tending measures will trigger a series of ecological environment problems. From the perspective of the sustainable development of ecological economy, it is not worth the cost. Therefore, it is significant to carry out a research on the surface runoff characteristics of the Eucalyptus plantation and its soil moisture content variation under the interference of different tending measures. It’s also important to reveal the soil and water loss problem of Eucalyptus plantation in afforestation tending process. So, it is necessary to offer some basic references for the scientific management and the sustainable development of Eucalyptus plantation.In this paper, on the basis of summarizing the relevant research both at home and abroad, five test (processing) have been set up in the Guangxi Heng county surrounding the reservoir of the new town, namely A handle (cut filling and cutting grass sprout regeneration, artificial woodland and weeding, basal dressing and fertilizer), B (fire to clear land, seeding update, chemical weeding, basal dressing and fertilizer), C (deforested bringing slope), D (artificial filling and cutting grass cut clean woodlands and weeding, seeding update, basal dressing fertilizer not only) and E (eucalyptus trees bud update 1 generation born stand 3 years). Each kind of woodland has been designed with two runoff plots, altogether 10 runoff plots. By located monitoring of runoff plot, practical investigation, indoor laboratory and mathematical statistics analysis, the author systematically studied the soil and water loss problem of Eucalyptus plantation and its soil moisture content variation under the interference of different tending measures, using the theory and methods of soil science, ecology, hydrology. The main results were as follows:1, According to the observation from July 1,2013 to December 31,2014, the total rainfall in experimental area is 2175.8 mm, and the annual average rainfall is 1450.5 mm. The differences among the surface runoff and sediment erosion with different rainfall level are very large (P<0.01), all presenting Torrential rain> Storm rain> The heavy rain> Moderate rain> light rain.2, Different tending measures have significant influence to the surface runoff and sediment erosion of Eucalyptus plantation. The surface runoff and sediment erosion of B treatment are the largest, which are respectively 117.54 mm and 1366.7 kg/hm2. (12.5% and 68.1% higher than A process,10.3% and 93.9% than C,15.6% and 84.6% than D,44.7% and 418.7% than E)3, The runoff nutrient concentration variation with different afforestation tending measures has an obvious difference:B process is maximal and E is minimal. What’s more, the surface runoff water nutrient concentration with different rainfall level has an obvious difference too:the nutrient concentration is highest when heavy rain with he content of N, P, K were 4.69 mg/L,0.24 mg/L,20.43 mg/L. The nutrient loss in the runoff water and sediment of B treatment is the largest:the runoff water loss N is 5.16 kg/hm2, P is 0.57 kg/hm2, K is 29.02 kg/hm2; the runoff sediment erosion of organic matter of B treatment is 53.78 kg/hm2, total N is 3.22 kg/hm2, total P was 0.35 kg/hm2, total K is 6.69 kg/hm2.Afforestation of different tending measures of woodland soil total N, P, K nutrient loss of treatment A 27.69 kg/hm2, respectively B with 45.01 kg/hm2, C processing 26.96 kg/hm2, D processing 28.05 kg/hm2,16.91 kg/hm2 E treatment. The size of the loss amount according to the B treatment> D treatment> A treatment> C treatment> E treatment. Woodland of N, P, K nutrients mainly through runoff water erosion, various treatment through runoff water loss of N, P, K nutrient content of total nutrient loss percentage were 82.8%,77.2%, 86.75%,83.4% and 91.4%.4, A treatment with the minimum of woodland soil moisture content,22.7%; Seasonal change different afforestation tending measures of soil moisture content, maximum in spring,21.1～25.7%; In winter the lowest 15.4～17.8%; Afforestation of different tending measures of soil moisture content were increased with soil from shallow to deep, but the difference between deep soil moisture content of soil is not obvious.5, According to the above research results, and considering the planting benefit of Eucalyptus plantation, soil and water conservation effect and the change of soil nutrient content, it suggests that in the planting process of Eucalyptus plantation, don’t use the fire burning and chemical weed control measures. Instead apply the root sprout regeneration and the artificial weeding method into cultivation to extend rotation cycle appropriately, which is to ensure the sustainable utilization of Eucalyptus forest soil and the ecological effect of Eucalyptus plantation. |
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