Study On Influencing Tendency Of Climatic Change On Typical Forests In The East China

A model FPBG is used to simulate the effect of climatic change on the productivity andstructure of southern typical forest ecosystem and six Quercus L. forest stand ecosystem. FPBGis a model of forest photosynthesis biomass growth, using the from-bottom-to-up method,coinciding individual photosynthetic rate model, growth model and forest gap model. Datainvestigated and collected are put into the FPBG model. With the simulated daily weather dataat normal and Hadley scenarios as driving variable, the FPBG model is operated. The operationresult is analyzed and studied. Reaction of forest ecosystem productivity and structure toclimatic change are discovered through functional types in two climatic situations and thechange of six Quercus L. forest biomass and stem number.Based on the exact situation of the study area, method of dividing functional types is usedto replace the many specific tree species in the south. Forest ecosystems in warm temperate,subtropical and tropical areas from north to south are divided into nine functional types,including warm temperate evergreen needle leave forest, warm temperate deciduous needleleave forest, warm temperate deciduous forest, warm temperate deciduous broad-leaved oakforest, south subtropical evergreen broad-leaved forest, north subtropical evergreen broadleaved forest, subtropical deciduous broad-leaved forest, subtropical deciduous needle leaveforest, tropical evergreen seasonal rain forest, etc. These nine functional types are simulated.Quercus L. forest is an important part of forest ecosystem, so that it is of greatsignificance to study the effect of climatic change on the ecosystem structure and productivityof Quercus L. forest stand. Six most common Quercus L. forest stand ecosystems are simulated,including Quercus mongolica, Quercus liaotungensis, Quercus variabilis, Quercus acutissima,Quercus aliena var. acuteserrata and Quercus patelliformis.Simulation results of nine functional types: First, after the climatic change, the averagebiomass and average stem number in plots of different functional types also change, while nomatter they increase or decrease, there is obviously a lag. That is to say, when some years haspassed after the climatic change, the average biomass and average stem number in plots ofdifferent functional types start to change evidently. Second, it can be concluded from thesimulated average biomass in different functional type plots and its percentage in differentclimatic belts that the percentage of simulated average biomass in needle leaved functionaltype plots is higher than that in broad-leaved ones. The average biomass of different functionaltype forest stands in low latitude areas is disturbed less than that in high latitude areas, andneedle leaved function forest stands adapt to the disturbance of climatic change better thanbroad-leaved ones. Simulation results of the six Quercus L. forest stand ecosystems: First, after the climaticchange, the average biomass and average stem number in plots of the six Quercus L. foreststands also change, while no matter they increase or decrease, there is obviously a lag. Second,since different forest stands are situated in different regions and have different biologicalcharacteristics, when the climate changes, the effect on them are different. The biomass ofQuercus mongolica increases slowly, the growth of biomass of Quercus aliena var.acuteserrata is obvious and that of Quercus liaotungensis fluctuates evidently. The biomass ofQuercus variabilis and Quercus acutissima changes and becomes stable when reaching somedegree. The biomass of Castanopsis patelliformis decreases. Third, after the climatic change,except the decrease of the biomass and stem number of Quercus patelliformis, the biomass andstem number of all the other five Quercus L. forest stand increases, although they increase todifferent degrees. That is to say, all the Quercus L. species have high adapting ability, which isone of the reasons why different Quercus L. species can be widely distributed in these regions.