鹤山退化生态系统恢复过程中土壤微生物的特性

Soil Microbial Characteristics in Rehabilitation Process of Degraded Ecosystems in Heshan

摘要:

对鹤山丘陵荒坡人工植被土壤生物特性进行了研究,结果表明鹤山人工植被中土壤微生物的数量以马占相思林较高,为6.164×10⁶ g^-1 drysoil,接近村边次生自然林(6.323×10⁶g^-1 drysoil);其次是果园和红荷木林,分别为5.115×106和4.083×10⁶g^-1 drysoil;松林中微生物数量最少,仅为1.424×10⁶g^-1 drysoil。土壤微生物的组成以细菌为主,占微生物总数的71.4%-87.7%,其次是放线菌,为总数的9.2%-22.7%,真菌相对较少(1.1%-9.6%)。细菌的数量与微生物总数的变化趋势相一致。人工植被中土壤微生物生物量(mgCmic(100g)-1drysoil)是马占相思林(57.11)>果园(47.79)>红荷木林(42.55)>松林(29.68),与相应的土壤有机碳(gC_orgkg^-1 drysoil)顺序相吻合[马占相思林(16.13)>果园(13.40)>红荷木林(12.59)>松林(11.89)],与土壤生物数量的变化趋势亦相似。与1988年用同一种方法的采样分析结果相比,人工植被中微生物的总数、细菌的数量及其占微生物总数的比率均有所提高,意味着在植被恢复过程中土壤质地得到了改善，其中以马占相思林的土壤恢复速率相对较快。

Abstract:

The amount and composition of soil microbes including bacteria, fungi and actinomycetes were investigated in July 2002 in Heshan Hillyland Interdisciplinary Station where afforestation was undertaken on waste downland since 1983. Soil samples were collected at 0-15 cm depth from plots of seven sites, i.e. I, Pinus massoniana forest (planted in 1983); II, Schima wallichii forest (1987)； III, Mixed forest of legumes (planted during 1983-1987)； IV, Acacia mangium forest (1983)； V, Orchard (1985)； VI Fish pond sludge(fish pond was established in 1985)；and VII，Secondary forest near village．Microbial am ount Was highest in site VII(6.323×10⁶g^-1 dry soil)，folowed byⅣ，V，Ⅱ,III,VI,and lowest inI(1.424xl06 g dry sold．111e number ofsoil microbes was in the order：bacteria > actinomycetes > fungi，which Was similar to the results obtained in l988．However，the percentage ofbacteria Was increased rapidly in all sites(from 32.1％-79.9％in 1988 to 71.4％-87.7％now)，and the percentage of fungi and actinomycetes were decreased (from 6.8％-28.6％and 6.8％-39.3％to 1.1％-9.6％and 9.2％-22.7％，respectively)．Soil microbial biomass(mg C_mic (100g)^-1 dry soil)in sites was in the order：IV(57.11)> V(47.79)>II(42.55)>I(29.68)，which had a similar sequence for soil organic carbon in the corresponding sites．The increase of total amount of microbes，especially ofthe number and percentage of bactefia suggests that the soil properties under artificial forests were improved， and most obvious result Was foun d in soil un der aforestation by Acacia mangium．