| Forest cycle theory suggests that forest communities are made up of mosaic patches which are on different stages of development. And people often use these indexes such as diameter, age, height as a standard when they divide patches. In order to reflect its real process of change and scientific truth better, the author considers that the study about dynamics of popula-tion patches should set the indexes such as age, species as the criterion for the classification of patches. When the division of patches, age determination has become particularly important, so we have collected 156 parse tree data in Heilongjiang Province Xiaoxing’anling pine forest and analyzed the relationship between the individual mature pine DBH and age and also ex-plore the terrain and competitive factors how to affect on pine DBH and age in this indirect method for determining the age of an individual pine. According to the fitting results, we have selected the appropriate regression equation and a representative sample, the pines are divided into I:0a～80a (young forest), age group Ⅱ:81a～160a (middle-aged forest), age group Ⅲ: 161a-200a (nearly mature forest), age group Ⅳ:201a～240a (mature forest), age group Ⅴ:> 240a (mature forest) five age groups with using geographic information processing software GIS and database development software Visual FoxPro. The patches of every age groups are divided by using the manner of raster processing and collected basic information. Research on characteristics about patches of different age groups and the dynamic cycle, and universal patches mosaic theory is briefly described. The results show:Elevation, slope, aspect, competitive factors and other factors have an impact on their age and pine diameter, especially aspect and slopes show the best fitting effects between the DBH and age. and the impact of competitive factors are smaller and perform difference in a differ-ent terrain. The pine individuals of the southern-middle slope show the best fitting results be-tween DBH and age. Based on the above findings with investigating the 10 plots in this pa-per,we selected the two different latitudes plots about 10.4 ha located in the south slope re-spectively and comparatively, which was Yichun Liangshui National Nature Reserve and Heihe Shengshan National Nature Reserve. We measured the age of korean pine of this plot through Linear Regression Equation, and the patches were divided in different age groups. We founded that it was mainly young patches in the Shengshan plot, however,it was mostly old patches in the Liangshui plot. And the differences of distribution ratio about patches of differ-ent age groups was significant. Meantime, we also founded that the two plots had two clear advantages in the age groups. For example the young and middle-aged forest was the dominant age groups in Shengshan plot and middle-aged and over-mature forest was the most age groups in Liangshui plot. Therefore we can clearly analyzed that the cycle of different stages of the forest. And this cycle was not continuous and uniform, there is hysteresis in the future period, which will directly affect a process of next patch or the next stage of the cycle. Because of the interference of this hysteresis, dynamic cycle of patches don’t have a unique period, which is the combination of two or more small cycles. We guess the length of time for large periods is the whole life course, and small cycles may be 40 years or 80 years. Meantime,we also found it shows significant mosaics within patches of different age groups in two plots. According to the previous studies and this exploration, we can initially consider that patches mosaic theory in different regions has been reflected well, it also have universal characteristics. |
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