Ecological Characteristics And Function Study Of Litterfall In Some Landscaping Forests In Shanghai

Field work of this investigation was conducted on nine forests in Shanghai: bare land, Cinnamomum camphora, Ligustrum lucidum, Metasequoia glyptostroboides, Koelrenteria paniculata, Populus tremuloides, Camptotheca acuminated, Albizia julibrissin, Elaeocarpus sylvestris. The results are as follows.1. Litterfall characteristicsThe annual amount of litterfall in C. camphora, L lucidum, M. glyptostroboides, K. paniculata, P. tremuloides, C. acuminatea, A. julibrissin, E. sylvestris were 6.247243 T/hm,11.21655 T/hm, 7.439026T/hm, 7.469681 T/hm, 4.886187T/hm, 2.977219 T/hm, 4.71117T/hm, respectively.The amount of dropped leaves were the largest, the amount of twigs, fruits and flowers were ranked as follows: K. paniculata, C. camphora, A. julibrissin, M. glyptostroboides were twigs > fruits > flowers, L lucidum were fruits > twigs > flowers, C. acuminatea and E. sylvestris were twigs > flowers > fruits. P. tremuloides forest had no flowers and fruits because P. tremuloides were crossbreed in this study.The amount of main forests total storages were ranked as C. camphora > K. paniculata > E. sylvestris > M. glyptostroboides > L. lucidum > P. tremuloides, the L layer storages were C. camphora > K. paniculata > E. sylvestris > L. lucidum > M.. glyptostroboides > P. tremuloides, the D layer storages were K. paniculata > C. camphora > M. glyptostroboides > E. sylvestris > L. lucidum > P. tremuloides, the H layer storages were C. camphora > K. paniculata > M. glyptostroboides > E. sylvestris > L. lucidum Ait > Populus tremuloides.The decomposition rate of C. camphora is 85.87%, annual amount of litterfall was smaller than the storage and the litter turnover coefficient is 1.1646. The decomposition efficient K were also ranked.2. Variation of physical and chemical propertiesThe effects on 0-10cm layers were larger than that of 10-20cm layers. The largest total porosity of 0-10cm layer was 1.38 times than that of bare land, but it's 1.32 timesfor 10-20cm layer.The organic matters of humus were the largest, that of 0-10cm layer were the second, the smallest were that of 10-20cm layer. But there were no distinct difference of soil layers for the other chemical properties. Furthermore, soil organic matter of M. glyptostroboides forest was the largest, but that of bare land was the smallest Total -N(?) of K. paniculate forest was the largest, available-N of bare land was the smallest. Except the PH was 6.52 of M. glyptostroboides forest, the other soils are alkaline.3. The amount dynamics of soil microorganismThe amount of bacteria in broad leaf forest soils were larger than that of conifers, the amount of epiphytes in broad-leaved forest soils were smaller than that of conifers. The bare land soil was so lean that amount of microorganisms was the smallest. The amount of microorganisms of Koelrenteria paniculata forest soil was the largest.The results showed that the physical and chemical properties were integrated correlated with the amount of microorganisms.4. Synthetical evaluation of soil fertilityTwenty two factors were used to evaluate the soil fertility IFI including maximum capillarity and minimum water holding capacity, water content of mass and volume, capillarity, non-capillarity and total porosity, soil density and aeration, content of organic matter, total N, total P, available N, available P, available K and PH, conductive rate, amount of bacterias, actinomyces, epiphyte and total microorganisms. IFI values of bare land, C. camphora, L. lucidum Ait, M. glyptostroboides, Koelrenteria paniculata, Populus tremuloides, Camptotheca acuminatea, Albizia julibrissin, Elaeocarpus sylvestris were 0.100,0.288,0.219, 0.581, 0.766,0.499,0.191, 0.456, 0.714.5. Influence of litter on the growth of seedlingsFor Distylium racemosum, the growth of height and rhizome were evidently improved; For the Cinnamoumum glanduliferrum, the growth of height and rhizomewere improved too; For the L. lucidum, inversely, the growth of height and rhizome were restrained. From the results we can see that the enhance of surviving rate of Distylium r...