Forest Management And Forest Ligneous Plant Variety

With accelerating of species extinction rate , conservation of biodiversity increasingly become a problem concerned by many scholars and experts . Forest is carries of biodiversity, The composite structure of stands intensity of disturbance and people' management idea have direct effect on biodiversity. I choose different forest type which has different mixture, ages, ways of site preparation, bandwidth of fore station belt and intensity of disturbance at Janlagou , a forestry center of the north east forest university for experiments in Maoershan, Shangzhi city, Heilongjiang province. Based on investigation, I studied their biodiversity and compared different ecological community at time scale and space scale by richness degree index, equality degree index and diversity degree index .The result is as follow: (1) The biodiversity of mixture woods is higher than that of pure woods, When environment gradient varies, variation of biodiversity of mixture woods is smaller than pure woods', If mixture tree species increase, biodiversity also enhance, but variation of biodiversity become smaller with environment gradient; The low density forestation favor the improvement of biodiversity, because stands can provided enough water nutrient and sunbeam for upgrowth of plants; site preparation broke vegetation of forest and cut down biodiversity the in a certain period, which doesn' t accord with the principle of biodiversity protection. (2)Moderate interference can improve biodiversity, With increasing of intention and frequency of cutting, unusual species decrease, and usual species increase, biodiversity descend; In closing stands, The influence that underlay upspring bring to the structure of canopy is not strong, doing so don't amend the inner conditions of stands, biodiversity is low-lying; Up-upspring bring good conditions for species of down-stands, form. many stand gaps, ameliorate stands condition, abundance of species, biodiversity increase, but the shade unusual species decrease.(3)Biodiversity of narrow stands is lower,because its area of forest-edge is small; Whatever we consider from renewing of the forest or protecting biological diversity, Clear cutting should not be adopted as a kind of way of forest main fell, because it is subversive for biodiversity ; For swarap, precipitous, drought and the place where amort animals and plants live in, the ecosystem of these places are very weak, Once biological diversity is damaged, It is very hard to recover, So we should try our best to reduce the interference and stop clear cutting, which match long benefits of human being.