Study On Seasonal Dynamic Of Leaf Area Index In Maoer Mountain

Leaf area index (LAI) is one of the most important structural parameters to describes leaf growth process. Our objectives were to measuring LAI-values in growing season, matching seasonal dynamics of LAI in Maoershan Mountain, Heilongjiang Province, China. To explore the seasonal variable rules of leaf area index for long time sequence in northern China, this paper, by using LAI-2000 to measure the LAI in 12 sample plots and monitor the seasonal dynamics.4 growth equations were used to fit the scattered LAI-values and calculate the growth rate of LAI and the cumulative LAI-values, then analyzed the seasonal variable rules of leaf area index under different site conditions. The LAI of 12 sites of deciduous broad-leaved forest was in a single peak growing season curve. Mitscherlich growth equation is the best fitting model to plots with poplar as the dominant tree species. For the sites located in the sunny slope, Richard growth equation is best. Logistic growth equation is best for birch tree and acer mono sites. Gompertz growth equation can used to fit the other sites. R2 in all kinds of growth equation to fitting LAI-values are higher than 0.962. In the 2014 survey, the highest LAI-value appeared in July. Between July and August LAI-values tended to be stabilized, in September begin to decline. The difference of LAI growth rules is bigger in the different slopes of the same spatial location and the highest difference quantity of cumulative leaf area index arrived 17.6%. This result of forest leaf area index dynamic variable rules provide a basis for future study in the spatial heterogeneity of vegetation and its impact and modeling carbon, water and energy from stand to landscape levels.