2025/03/07 by Yan Wang, Yawen Xu, Cunzhi Jia +1 · 1 voice
Environmental Science · #Ecology and Vegetation Dynamics Studies #Plant Water Relations and Carbon Dynamics #Rangeland and Wildlife Management
paper · pdf · doi:10.1111/1365-2664.70023
openalex publication_date 2025/03/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/05/30
Abstract Open‐top chambers (OTCs), widely used as field warming facilities, not only generate warming effects but also reduce water availability through the rain interception effect. While OTCs are extensively applied to explore the effects of warming on seedling recruitment which act as a fundamental driver of population dynamics, the potential experimental biases introduced by the rain interception effect remain largely unexplored. This knowledge gap raises concerns about the interpretation of warming experiments using OTC facilities. We conducted warming experiments in alpine meadows on the Tibetan Plateau using OTCs. Three treatments were applied: control (no OTC), warming alone (W, +2°C without OTC precipitation interception) and warming with decreased precipitation (WDP, +2°C with OTC precipitation interception). Focusing on 50 plant species across various functional groups, we disentangled the independent effects of warming and decreased precipitation caused by OTC interception on seedling emergence, survival and establishment. We applied structural equation modelling (SEM) to analyse the relationships between emergence timing, rate, survival and establishment success. Our study demonstrates that W and WDP treatments accelerated seedling emergence but decreased survival and establishment rates at the community level. The WDP reduced survival by 20% compared to W. The SEM analysis revealed that earlier emergence and higher emergence rates under W indirectly reduced establishment success, while WDP directly suppressed survival by limiting water availability. Furthermore, W increased the biomass of grasses and perennials, whereas WDP significantly reduced their biomass. In contrast, annuals and non‐grasses showed no significant response to either treatment. Synthesis and applications . The OTC‐induced precipitation reduction can overestimate the impacts of warming on seedling establishment success, with species and functional group‐specific responses. Therefore, interpreting data from OTC warming experiments requires careful consideration of precipitation interception effects. To mitigate this issue, future studies should optimize experimental designs to minimize precipitation interception, incorporating methods such as collecting and redistributing precipitation to better support seedling water availability. Furthermore, to enhance ecosystem resilience and support biodiversity in the context of climate change, conservation strategies should prioritize species and functional groups that are especially vulnerable to changes in warming and precipitation.