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土壤微生物在生态系统生物地球化学循环过程中扮演着重要角色,对于受到干扰后退化土壤的肥力恢复具有重要的意义,然而,采伐后次生林发展过程中土壤微生物生物量的动态尚不明确。在帽儿山森林生态站的落叶阔叶林中设置了一个由采伐后0年(采伐迹地)、10年、25年、56年的林分构成林龄系列样地,采用氯仿熏蒸浸提法,在生长季期间(4–10月)每月测定各林分土壤微生物生物量碳含量(C_(mic))、微生物生物量氮含量(N_(mic))、土壤可溶性有机碳含量(Cdis)、可溶性全氮含量(Ndis)、土壤含水率、温度等因子,以探索采伐干扰后不同林龄林分土壤微生物生物量的时间动态及其影响因子。结果表明:(1)不同林龄林分土壤微生物生物量生长季均值差异显著,C_(mic)表现为56年和采伐迹地显著高于25年和10年林分;N_(mic)表现为采伐迹地、56年显著高于10年林分,25年林分居中;C_(mic)/N_(mic)表现为56年、10年林分显著高于25年林分、采伐迹地。(2)采伐迹地微生物生物量季节变化格局与其他3个林龄林分的差异主要体现在生长季后期,前者表现为降低,而后者表现为升高或变化不明显;10年、25年、56年林分C_(mic)、N_(mic)季节变化格局的差异主要体现在生长季前期,变化幅度随林龄增长而降低;4个林龄林分C_(mic)/N_(mic)季节变化均表现为“W”形。(3)土壤微生物生物量的主要影响因子随林龄而变:随林龄增长,C_(mic)、N_(mic)的影响因子由土壤含水率(采伐迹地、10年生)逐渐转变为土壤可溶性养分含量(10年、25年、56年林分);采伐迹地C_(mic)/N_(mic)影响因子为土壤温度和Cdis,其他3个林龄林分则为Cdis/Ndis。这些结果说明:在采伐干扰后的次生林发展过程中,植被组成和土壤理化性质不断变化,提高了土壤微生物生物量,进而改善了土壤养分状况,显示出地上植被变化与地下微生物动态的密切联系。
Soil microbes play an important role in the biogeochemical cycle of ecosystems and are of great significance to the fertility restoration of degraded soils after disturbance. However, the dynamics of soil microbial biomass during the development of secondary forests after harvesting are not yet clear. In the deciduous broad-leaved forest at Maoershan Forest Ecological Station, a series of samples were collected from forest stand 0 years after harvesting (logging land), 10 years, 25 years and 56 years, and fumigation with chloroform Soil microbial biomass carbon (C_ (mic)), microbial biomass nitrogen (N_ (mic)), soil soluble organic carbon content (Cdis) Total nitrogen content (Ndis), soil water content, temperature and other factors in order to explore the time-varying dynamics of soil microbial biomass and their influencing factors after cutting disturbance. The results showed that: (1) The mean values of soil microbial biomass in different stand ages were significantly different. The average performance of C_ (mic) was 56 years and that of deforestation was significantly higher than that of 25 and 10 years. N_ (mic) In 56 years, it was significantly higher than that in 10-year forest and 25-year-old forest. C_ (mic) / N_ (mic) showed 56 years and ten-year forest was significantly higher than that of 25-year forest. (2) The seasonal variation pattern of microbial biomass in the cutting sites is different from the other three stand ages mainly in the later growing season, the former shows a decrease, while the latter shows no obvious change or change; 10 years, 25 years, The differences of seasonal changes of C_ (mic) and N_ (mic) in 56 years stand mainly in the early growth season and the variation range decreases with the growth of forest age. In the four stands, Changes are manifested as “W ” shape. (3) The main influencing factors of soil microbial biomass changed with stand age: With the increasing of age, the influence factors of C_ (mic) and N_ (mic) gradually changed from soil moisture content (10 years) Nutrient content (10 years, 25 years and 56 years stands); C_ (mic) / N_ (mic) influencing factors of soil cover were soil temperature and Cdis, while those of the other three stands were Cdis / Ndis. These results show that the vegetation composition and soil physical and chemical properties change constantly during the secondary forest development after logging disturbance, which improves soil microbial biomass and soil nutrients, and shows the close relationship between aboveground vegetation changes and the dynamics of underground microorganisms.