Study On Population Characteristics Of Acer Catalpifolium

Acer catalpifolium is a unique national level II wild protected plant in China,a precious and endangered species.The number of individuals of Acer catalpifolium is sparse,and the habitat requirements are strict.The population area has been gradually reduced due to various factors.This paper takes the distribution of Acer catalpifolium in Sichuan Province as the research object,combined with the research method of population ecology,from the habitat characteristics,population and number of individuals,population age structure,intraspecific and interspecific competition,and its protection countermeasures were studied of Acer catalpifolium,to provide a scientific reference for the restoration and reconstruction of the natural population of Acer catalpifolium.The main results are as follows:1.The populations of Acer catalpifolium in Emei Mountain and Dujiangyan area are obviously different.There are 105 populations in Emei Mountain and 81 in Dujiangyan population.The diameter structure of Acer catalpifolium population is a degenerate population.The population age of two regions under random disturbance the structural dynamic index(Vpi')is 0.011 6 and 0.004 2,both of which are close to 0,and generally shows a degenerate structure transformed from stable to degraded.2.Analysis of life table and related curves showed that the number of early individual deaths was higher,and the number of survivors decreased with age,it has a strong effect on habitat selection;Survival curve tended to Deevey-? type,age groups have similar mortality rates;Survival function analysis shows that the survival rate function S(t)of the two populations tends to decrease monotonously with the increase of age,while the cumulative mortality F(t)shows a monotonous upward trend;The time series prediction analysis indicated that the age-old individuals of Acer catalpifolium gradually increased after 2,4,6 and 8 years of age,while the younger individuals decreased,the stability of the population decreased.If the seedlings in the population were difficult to supplement,the population of Acer catalpifolium will become a declining population.3.There are many small-diameter and middle-diameter trees in the population,and there are few high-diameter trees,there is a significant power function relationship between DBH and tree height.The total competition intensity of Acer catalpifolium intraspecific is 33.79,accounting for 15.16%of the total competition intensity,the total competition intensity between species was 189.08,accounting for 84.84%of the total competition intensity,the competition mainly came from species.The main tree species competing with Acer catalpifolium are Cryptomeria fortunei,Phoebe zhennan,Quercus fabri,Bothrocaryum controversum;the distance between the target wood and the competition wood and the competition index obey the exponential function,and the competition index decreases with the distance and finally flattens out.4.The total competition intensity(intraspecific and interspecific competition)decreases with the increase of the object wood DBH,when the object wood DBH is less than 20 cm,the competitive pressure is the greatest,when the object wood DBH is greater than 20 cm,the competition intensity changes little and the competition index is low.The competition strength and the object wood DBH are better obey the power function relationship(CI=AD-B),this model can predict the intra-and inter-species competition intensity of Acer catalpifolium.The prediction results of the model indicated that the competition index decreased with the increase of DBH,and the competition intensity decreased.When the DBH was greater than 20 cm,the competition index did not change much.5.The protection of Acer catalpifolium population should be based on in situ conservation,strengthen the protection of Acer catalpifolium population and habitat,at the same time as in situ conservation,human intervention should be carried out to pruning or cutting the associated tree species that affect its growth before the DBH of Acer catalpifolium reached 20 cm.The artificial propagation technique of Acer catalpifolium should also be carried out,research on population regression,increase propaganda work,strengthen awareness of conservation,and promote the continuation of the population of Acer catalpifolium.