Journal Article

Impact of plateau pika (Ochotona curzoniae) burrowing-induced microtopography on ecosystem respiration of the alpine meadow and steppe on the Tibetan plateau

Li, Ruicheng, Tian, Lihua, Wei, Haixia, Tang, Yanhong, Zhao, Jingxue, Bai, Yanfu, Zhang, Tao

2021

Overview

Background Alpine ecosystem underlain by permafrost is considered as one of the most vulnerable ecosystems to disturbance, especially the alpine grassland on the Tibetan plateau with an altitude above 4000 m. Plateau pika ( Ochotona curzoniae ) burrowing can create distinctive bare grounds and cause micro-topographical heterogeneity in alpine grasslands. The burrowing-induced changes in microtopography may directly alter plant and soil interactions as well as ecosystem carbon cycle, which have rarely been studied in Tibetan alpine grasslands. Methods To test the responses of ecosystem respiration (Re) to pika burrowing-induced changes in microtopography, we investigated plant characteristics, soil properties and Re from the bare grounds and vegetated grounds in the alpine meadow and steppe on the Tibetan Plateau. Results Our study showed that vegetation cover, species richness, plant biomass, soil moisture (SM), soil organic carbon (SOC), total nitrogen (STN), soil microbial biomass carbon (MBC) and nitrogen (MBN) in the bare grounds were significantly lower than in the vegetated grounds in both alpine meadow and alpine steppe ( P  < 0.05). However, soil temperature and inorganic nitrogen tended to increase in the bare grounds. The growing season Re was significantly lower in the bare grounds than that in the vegetated grounds ( P  < 0.01). Pika burrowing had negative effects on Re and its temperature sensitivity in both alpine vegetations ( P  < 0.05). The relative changes in Re due to burrowing-induced changes in microtopography were positively correlated with the burrowing caused changes of AGB, BGB, SOC and MBC ( P  < 0.05). Pika burrowing-induced changes in soil temperature, soil moisture, plant biomass and microbial biomass are the major factors for the decrease of Re in the bare grounds. Conclusion In view of the large number of pika burrows in the alpine grasslands and the loss of soil organic carbon due to pika bioturbation, the impacts of pika burrowing-induced changes in microtopography on Re must be considered in predicting the carbon cycle in alpine grasslands.

• Publisher: Springer Science + Business Media,Springer International Publishing,Springer,Springer Nature B.V
• Subject: Alpine ecosystems / Alpine environments / alpine grasslands / alpine meadows / altitude / Analysis / Biomass / Biomedical and Life Sciences / Bioturbation / Burrowing animals / Burrows / Carbon / Carbon content / Carbon cycle / Carbon cycle (Biogeochemistry) / China / Ecology / ecosystem respiration / Ecosystems / Grasslands / Growing season / Growth / Heterogeneity / Influence / Life Sciences / Meadows / microbial biomass / microbial carbon / Microorganisms / microrelief / Mountain ecology / Nitrogen / Ochotona curzoniae / Organic carbon / Permafrost / phytomass / Plant biomass / Plant Physiology / Plant Sciences / Plant-soil relationships / Regular Article / REGULAR ARTICLES / Respiration / Soil erosion / Soil investigations / Soil moisture / soil organic carbon / Soil properties / Soil Science & Conservation / Soil temperature / soil water / Soils / Species richness / Steppes / Temperature effects / Test procedures / total nitrogen / Vegetation cover