Basic Research On Typical Forest Health Management Technology In Rocky Mountain Area Of Northern China

Forest is resources for human survival and cradle of humanity. The forest is the main body of the terrestrial ecosystem, and the material basis for the survival and development of humans and all creatures on Earth. Forest sustainable management become the key of the development of the world forestry, how can scientific and rational cultivation, operation and protection the forest resources is a major problem in today’s forestry. The world’s existing forest were mostly formed after human disturbance and has rarely completely free from human interference. The natural forest had a long history, have combined with a variety of conditions on the ground to form best suited to local optimal forest stand. How to make secondary forest and plantation forest nearly naturaliz to become the focus of world forestry research subject. In this study, it used stand spatial structure to study the several typical forest stand in north China, judge the growth conditions and the forest stand management and operation diagnosing, and propose the design program of optimization operating.Investigation and experiment in three kinds of forests including planted Pinus tabulaeformis, planted larch forest and natural secondary forest were completed at Beigou forest farm in Mulan forestry administration in Weichang county of Hebei province during2009-2012, to analysis and design of forest structure and management. The main findings are as follows:The plantation forest are different from the secondary forest, forest stand density of plantation forest affect the growth and development, the operations designed of plantation forest adjust primarily to the stand density. For example Pinus tabulaeformis and Larix principis plantation, based on the actual forest growth conditions and stand uniform angle, neighborhood comparis, mingling and so on, four typical plots were operated design. It was took into account the adjustment of the stand diameter structure, and removed the forest which were in unhealthy and pressurized, cultivated the large diameter trees and promoted the development of the understory biodiversity.(1) The diameter distribution of Pinus tabulaeformis plantation was normal distribution, there were rarely update tree species and no larger diameter at breast height of trees; Forest stand DBH and tree height presented a positive relationship, forest branches under high and tree height have a relationship, but it is not obvious; The average uniform angle of Pinus tabulaeformis was0.4125in the15th plot, the average neighborhood comparis was0.4931, and average mingling was0.3556; In the19th plot, stand average uniform angle was0.3842, the average neighborhood comparis was0.5079, and the average mingling was0.0053;(2) The diameter distribution of Larix principis plantation was normal distribution, there was no larger diameter at breast height of trees; The stand DBH of Larix principis forest and tree height presented a positive relationship, forest branches under high and tree height have the relationship, but it was not obvious; The average uniform angle of Larix principis plantations was0.447in the2th plot, the average neighborhood comparis was0.5076, and average mingling was0; In the3th plot, stand average uniform angle was0.4458, the average neighborhood comparis was0.5, and the average mingling was0;(3) The litters thickness of Pinus tabulaeformis and Larix principis were6.1cm and4.0cm, the litters volume were33.93t·hm-2and43.16t·hm-2; The water content of Pinus tabulaeformis litters soaked was268.10g after24h, Larix principis litters water content was157.54g, and the effective interception amount were30.07t·hm-2and57.56t·hm-2;(4) The throughfall of Pinus tabulaeformis, canopy interception and stemfall accounted for67.07%,29.79%and3.10%of gross rainfall. The Larix principis were69.49%,28.82and1.1%; Throughfall, stemflow had a significant relationship with the total rainfall, the canopy interception and rainfall was into the power function relationship.Natural secondary forest management through the stand uniform angle, neighborhood comparis, minglingand competition index as the basis, to remove the bent forest, squeezed forest, the irrational space structure, no culture of the future and mature trees for the stand structure adjustment, keeping species other than populus davidiana and Betula platyphyllas, in order to improve forest mingling. After appropriately tending, implanted the Pinus tabulaeformis, Larix principis, spruce and other conifer species in stands, it can not only provide a certain timber, and achieve the purpose of the development of the stand to near natural direction.(5) The diameter distribution of populus davidiana stand was substantially down "J" shape, stand average uniform angle was0.517, trees were in a random distribution, the average neighborhood comparis was0.4922, average mingling was0.3156. The intraspecific competition index was the largest of populus davidiana, the competition Index was1306, the populus davidiana, Betula platyphylla and Larix principis occupied the absolute dominance in stands;(6) The diameter distribution of Betula platyphylla stand was substantially down "J" shape, the stand average uniform angle was0.566, forest stands belonged to the reunion distribution, the average neighborhood comparis was0.4892, the average mingling was0.4176. The intraspecific competition index was the largest of Betula platyphylla, the competition Index was3136. The Betula platyphylla and Larix principis occupied the absolute dominance in stands;(7) The diameter distribution of mixed Populus davidiana and Betula platyphylla stand was a normal distribution, average angular uniform angle was0.545, forest stands belonged to the reunion distribution, the average neighborhood comparis was0.488, and the average mingling was0.5101.The intraspecific competition index was the largest of Larix principis, the competition index was305, the Betula platyphylla and Larix principis occupied the absolute dominance in stands;(8) The diameter distribution of mixed Betula platyphylla and Populus davidiana stand was a normal distribution, the average angular uniform angle was0.5435, forest stands belonged to the reunion distribution, the average neighborhood comparis was0.4892, and the average mingling was0.5089. The intraspecific competition index was the largest of Larix principis, the competition index was332, the Betula platyphylla and Larix principis occupied the absolute dominance in stands.The species diversity, stand composition, stand diameter distribution, uniform angle, neighborhood comparis and competitiveness index were used to evaluate for Pinus tabulaeformis plantation, Larix principis plantation and natural secondary forest. The other stand species diversity and mingling were improved except Larix principis plantation, the proportion of top species were improved; the density of the plantation were low by adjusting, natural secondary forest are randomly distributed, while it was reduced the intraspecific competition and interspecific competition, and improved the competitive advantage of the top species.