Land use change (LUC) in tropics, explicitly from forest to conventional agriculture, is negatively affecting soil health and productivity. However, effect of such LUC on soil biological properties are poorly known in dry tropical environment.
In a study published in Ecological Indicators, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) tried to assess the effects of land use, seasonality and soil resource availability on soil biological properties within same soil type in Vindhyan highland in central India.
The researchers analyzed soil biological responses by measuring soil microbial activity (soil microbial biomass C, soil basal respiration or CO2 efflux) and hydrolytic and oxidative enzyme activities in the forest, fallow and agriculture land under the influence of LUC, soil resource availability and climate seasonality.
They found that land use change significantly affected soil C, N and P resources in topsoil. The seasonal variations of microbial variables were strongest in the forest followed by agriculture and fallow. The oxidative enzymes (particularly peroxidase) activity was higher in agriculture followed by forest and fallow.
The biological variables were showing similar seasonal variation among land uses, though the greater extent of seasonal variability was in the forest than fallow and agriculture, indicating LUC also altered the level of seasonal variation in biological properties.
Examination of soil resources (C, N and P) revealed that soil organic carbon fractions, inorganic and total N and P are the underlying drivers of soil biological variables during such type of LUC and climate seasonality.
Moreover, oxidative enzymes showed weaker coupling with those soil resources, indicating that these enzymes are also regulated by other factors in the ecosystem (e.g. climatic stress, ontogeny and defense).
“Our study reveals the significant effects of deforestation and agriculture on soil biological activities and improve our understanding of the potential mechanism driving these effects”, said Ashutosh Kumar Singh, an Indian postdoc with XTBG.
LIU Wenjie Ph.D Principal Investigator
Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China