论文部分内容阅读
于缙云山阳坡同一海拔高度处选择亚热带常绿阔叶林(简称林地)、撂荒地、坡耕地和果园这4种土地利用方式,在0~60 cm的土壤深度内每隔10 cm采集一个土壤样品,测定大团聚体(>2 mm)、中间团聚体(0.25~2 mm)、微团聚体(0.053~0.25 mm)以及粉+黏团聚体(<0.053 mm)内的微生物生物量碳(MBC)和微生物生物量氮(MBN)含量,以分析缙云山不同土地利用方式对团聚体MBC及MBN的影响.结果表明4种土地利用方式下,各粒径团聚体MBC及MBN含量均随土壤深度的增加而降低.林地开垦为果园和坡耕地后除导致大团聚体MBC和MBN含量升高外,其它粒径团聚体MBC及MBN含量均降低;坡耕地撂荒后,除粉+黏团聚体MBN含量降低外,其它粒径团聚体MBC及MBN含量均增加.采用等质量方法计算了0~60 cm土壤深度内4种土地利用方式下各粒径土壤团聚体MBC和MBN的储量,发现除粉+黏团聚体外,其他粒径团聚体MBC储量均为林地高于果园和坡耕地,撂荒地各粒径团聚体内的MBC储量均高于坡耕地;MBN储量表现为中间团聚体和微团聚体林地高于果园和坡耕地,而撂荒地除粉+黏团聚体外,其他粒径团聚体均高于坡耕地.总体上,林地和撂荒地团聚体MBC储量高于果园和坡耕地,MBN储量高于坡耕地,果园与林地团聚体MBN储量接近,表明林地的垦殖虽然对果园团聚体MBN影响非常小,但却导致了团聚体MBC以及坡耕地MBN的损失,而坡耕地撂荒则有利于团聚体MBC及MBN的恢复和蓄积.在土地利用转变过程中,土壤团聚体MBC的变化方向和变化量与土壤有机碳并不一致,存在很大的差异,因此,土壤团聚体微生物熵并不适于来评价该地土地利用变化对土壤的影响,采用有机碳总量作为表达土地利用变化的敏感性指标可能更好.
At the same elevation of Jinyun Mountain, four soil types were selected: subtropical evergreen broad-leaved forest (forest land), fallow land, sloping farmland and orchard. Soil was collected every 10 cm in 0-60 cm soil depth The microbial biomass carbon (MBC) was measured in large aggregates (> 2 mm), middle aggregates (0.25-2 mm), microaggregates (0.053-0.25 mm) ) And microbial biomass nitrogen (MBN) were measured to analyze the effects of different land use types on aggregates MBC and MBN in Jinyun Mountain.The results showed that the contents of MBC and MBN of aggregates with different particle sizes varied with soil depth Increase and decrease.The contents of MBC and MBN in other aggregates decreased after the land reclamation was in orchard and sloping farmland except for the increase of MBC and MBN in large aggregates, The content of MBC and MBN of other aggregates with different particle size increased.Using the same mass method, the reserves of MBC and MBN in soil aggregates with different grain sizes under four land use types in 0-60 cm soil depth were calculated, The sticky aggregates, the other size aggregates MBC reserves are higher than the woodland The MBC reserves in each size aggregates of orchards and sloping fields and abandoned land were higher than that of sloping fields. The MBN reserves of middle aggregates and microaggregates were higher than that of orchards and sloping fields, In other words, the MBC reserves of aggregates in forestland and fallow was higher than that in orchards and sloping fields, MBN reserves were higher than those in sloping fields, MBN reserves of orchard and forestland aggregates were close, which indicated that the reclamation of forestland However, it caused the loss of aggregate MBC and sloping farmland MBN, while the shortage of sloping farmland was conducive to the recovery and accumulation of aggregates MBC and MBN.In the process of land use change, soil aggregates Therefore, the micro-entropy of soil aggregates is not suitable for evaluating the impact of land-use change on the soil. The total amount of organic carbon as the expression of land It may be better to take advantage of changing sensitivity indicators.