Recovery of soil microbial biomass, stoichiometry, and herb‐layer diversity with chronosequence of farmland land abandonment in the central Himalayas, India

Abstract

Revegetation after farmland abandonment not only changes the aboveground biodiversity but also soil physicochemical properties and soil microbial biomass. However, how the revegetation after farmland abandonment influences soil properties and herb‐layer biodiversity remains unclear. In the present study, we examined the variation in soil chemical and biological properties (soil microbial biomass, stock, and stoichiometry), herb‐layer diversity indices, and aboveground biomass, their relationships in a chronosequence of 2, 5, 7, 11, 16, and 35 years following revegetation of abandoned farmland in the central Himalaya, India. Results revealed that the diversity indices, biomass, and soil properties significantly changed over successional stages. The species in the plant community shifted from the forbs in earlier stages to grasses and sedges in later stages. Our results indicated that the soil microbial carbon (C) and nitrogen (N) contents and stocks increased along the chronosequence and were highest at the 35‐year‐old fallow. However, soil microbial phosphorus (P) contents and stock generally decreased with time. The soil nutrient and microbial biomass were significantly correlated, which indicate close coupling between soil and microbial C, N, and P contents. Soil, microbial C/P, and N/P ratios were the lowest in 7‐ and 11‐year‐old fallows, indicating that middle‐aged fallows were more P‐limited. Our results suggest that revegetation changes the soil and microbial stoichiometry, potentially changing the vegetation composition and nutrient cycling of the abandoned farmland ecosystems.

Responses of Soil C, N, and P Stoichiometrical Characteristics, Enzyme Activities and Microbes to Land Use Changes in Southwest China Karst

“…The present results confirmed that soil microbes were affected significantly by land use changes. Land use affected the soil microbial community structure by changing soil salinity and alkalinity, pH, moisture content, organic matter content, and so on [38]. The present result that the biomass of soil total microbes, actinomyces and fungi in forest land were all the highest could be due to the high coverage of litters and a large number of plant roots in the forest land.…”

Effect of forest chronosequence on ecological stoichiometry and nitrogen and phosphorus stocks in Alnus nepalensis forest stands, central Himalaya

“…To evaluate the microbial efficiency of SOC, TN, and TP concentrations, the soil microbial quotients MBC:SOC, MBN:TN, and MBP:TP ratios were calculated (Joshi et al, 2022; Joshi & Garkoti, 2023). In each plot, the N and P stocks in different vegetation components were obtained by multiplying the N and P concentrations of the vegetation components by the total biomass of that component.…”

Depth-Wise Distribution of Soil Chemical Properties, Micro-nutrients Status, and Bacterial Population under Quercus leucotrichophora and Shorea robusta Forest of Chakrata and Thano Region of Uttarakhand

“…All these processes play a significant role in plant nutrition, and one microorganism that produces thermostable lipase was isolated from soil collected from the Himalayan region" [16]. "Abandoning agricultural land in Central Himalaya has become a trend in the past few decades due to the ruralurban migration in the region for gainful employment and livelihood opportunities" [17]. "Much research has been conducted in the current context of vegetation types to compare the influence of vegetation on SOC and nutrients, microbial biomass, and soil respiration" [2,18,19…”