Study On Individual Tree Growth And Competition Effect Of In Different Management Kinds Of Chinese Fir Population

Competition is important factor witch impacted on the growth, studying on the growth element and cowpetition element of different kinds of Chinese fir plantation is both theoretic significance and important utility value.The average D of Cunninghamia lanceolata is 0.94,2.81,1.77,1.06,andl.47 timeslarger than that of Sassafras tsumu, Phobe burnei.Fokienia hodginsii,Cinnamomum camphora,Tsoongiodendron odorum and Alniphyllum fortunei,respectivity.Similarly, the mean height is 0.9,1.72,1.14,1.17,0.93and0.98times and the average productivity per individual is 0.85,9.31,1.71,3.23,1.09and 2.12 times greater than that of the 6plants. Through the comparesion.fir in mixed forests grew better than it in pure stand.Study spatial distribution of plant population with different crown breath can give the information for the mechanism of population distrbution. Fractal geometry of crown is considered to be a very useful tool for dealing with the distribution of crown.Jn this paper, the fractal dimension of different species crown in the pure Chinese fir plantation, Chinese fir plantation mixed with Sassafras tsumu (Hemsl.) hemsl and Chinese fir plantation mixed with Phoebe bourner (Hemsl.) Yang and Chinese fir plantation mixed with Fokienia hodginsii (Dunn) Henry et Thomas were calculated and compared. The results indicated that the fractal dimension of Chinese fir which mixed with Sassafras tsumu (Hemsl.) hemsl is larger than the others, the fractal dimension of two species in Chinese fir plantation mixed with Fokienia hodginsii (Dunn) Henry et Thomas are larger than that of the pure Chinese fir plantation; these showed that the interspecific competition of variable populations was not intense. On the contrary, the intraspecific competition was very intense.taking the pure Chinese fir plantation, Chinese fir plantation mixed with Alniphyllum fortumei and Chinese fir plantation mixed with Tsoongiodenron odorum as an example, comparing them with different scale and statics index, The results indicated that the fractal dimension of Chinese fir which mixed with Tsoongiodenron odorum is larger than the others, the fractal dimension of two species in Chinese fir plantation mixed with Alniphyllum fortume are larger than that of the pure Chinese fir plantation; the fractal dimension of Tsoongiodenron odorum is larger than that of Alniphyllum fortumei; these showed that the interspecific competition of variable populations was not intense. On the contrary, the intraspecific competition was very intense.The competition among trees within a stand includes aboveground and underground parts, we define the distance from nearest competitors to subject tree as inside radius, in which, the competition influence is the sum of both aboveground and underground; the distance of competitors to subject tree as outside radius, where the competition influencecomes mostly from underground. We used the data of Cunninghamia lanceolata(Lamb.) Hook pure stand, Cunninghamia lanceolata(Lamb) Hook with Alniphyllum forturei(hemsl.) Makino mixed stand and Cunninghamia lanceolatafLamb.) Hook with Tsoongiodendron odorum Chun mixed stand to analyze the competition influence of aboveground and underground in inside and of underground in outside radius. The results show that for Cunninghamia lancealata(Lamb.) Hook in pure stand, the competition effect come from outside radius was stronger than from inside radius. In mixed stands, for Cunninghamia lanceolatafLamb.) Hook, the effects of competition come from intraspecific stronger than from interspecific competitors, for Alniphyllum forturei(hemsi) Makino or Tsoongiodendron odorum Chun, the effects of competition come from interspecific stronger than from intraspecific competitors. In addition, the individual growth effection of Cunninghamia lanceolata(Lamb.) Hook in mixed stand is better than that in pure stand.Based on the data,Hegyi's competition index model for individual tree was introduced to study intraspecific and interspecific competition for different management types o...