Analysis On Microsite Of Picea Schrenkiana Natural Regeneration And Seedling Spatial Pattern And Dynamic

The seedling natural regeneration relies on many microsite factors. The microsite is advantageous or not, has the decision to the seedling the occurrence pattern, becomes the determining factor of plant seed, affects the seedling to survive this extremely sensitive ecology process. This thesis takes Picea schrenkiana as the research object and adopting geo-statistical theory,methodology,spatial point pattern analyse,ordination of DCA to analyze spatial pattern and dynamics of Picea schrenkiana seedlings, and spatial heterogeneity of difference environmental variables of microsite in Picea schrenkiana stand which altitude from 1800 to 2300m and the environmental variables effect on seedlings natural regeneration, the results as following:Quantitative analysis the heterogeneity character of different microsite environmenttal variables in Picea schrenkiana stand,and draw the conclusions as following:All environmental variables of microsite have significance heterogeneity, the list of auto- correlated scales of environmental variables is litter thickness(19.43m),litter biomass(19.02m), herb layer biomass(14.38m),litter cover(9.35m), light intensity (9.31m),moss thickness(6.63m), moss cover (6.11m),humus thickness (4.23m),soil temperature (3.21m), bulk density(1.58m),soil water(0.87m), herb cover(0.54m),moss biomass(0.42m),herb thickness (0.26m).Applying ordination of DCA to classify Picea schrenkiana seedlings microsite into three types:herb-moss habitat type,non-ground layer habitat types,litter habitat type. Most Picea schrenkiana seedlings recruitment happen in July and August,and Picea schrenkiana seedlings have higher mortality in winter and spring, Among the three habitat types, the number of seedling recruitment most type is herb-moss habitat,non-ground layer habitat in middle and the least was litter habitat type. To the seedlings perish process,litter habitat type has higher recruitment seedlings number, the moss-herb habitat type is most stabilized in mortality.Ripley ' s K ( r )and O-ring statisticwere adopted to research the spatial pattern and relation of Picea schrenkiana seedlings, draw the following conclusions that: within the range (0～5m),beside the 5 year-old seedling is complete spatial randomness at 0～2.7m,within the other range,seedlings spatial pattern is aggregation, the maximum congregate intensity and the maximum congregate intensity have no correlation with the age of seedlings; within the range of (0～5m),according to spatial point-pattern studied result, the inter-species relations between all of uneven-aged seedlings are significant attraction, uneven-aged seedlings take the real meaning of individual plant one after another, except 1 year-old and 5 year-old seedlings are patch incrustation within the range of 0～1.5m,and uneven-aged seedlings appear seedling waves at integral meter.Environmental variables effect the 1 year-old year seedling pattern are moss cover,litter cover; herb thickness, light intensity,and the first two variables are positive to1 year-old seedling, the last two are negative to 2 year-old seedlings, light intensity, soil temperature, humus thickness, herb thickness, herb cover are positive, moss cover and litter are negative to 3 and 4 year-old herb thickness and light intensity have more violence, litter become negative effect to 5 year-old seedlings, moss cover is positive, litter cover and bulk density are negative. At least 5 years spend to go through the high mortality for Picea schrenkiana seedlings.