Divergent Responses of Community Reproductive and Vegetative Phenology to Warming and Cooling: Asymmetry Versus Symmetry.

Fandong Meng,Tsechoe Dorji,Zhezhen Wang,Wangmu Renzeng,Qi Wang,Lili Jiang,Shiping Wang,Peipei Liu,Wangwang Lv,Zhenhua Zhang,Bowen Li,Mingyuan Du,Ji Suonan,Haishan Niu,Lirong Zhang,Caiyun Luo,Jichuang Duan

doi:10.3389/fpls.2019.01310

Abstract

Few studies have focused on the response of plant community phenology to temperature change using manipulative experiments. A lack of understanding of whether responses of community reproductive and vegetative phenological sequences to warming and cooling are asymmetrical or symmetrical limits our capacity to predict responses under warming and cooling. A reciprocal transplant experiment was conducted for 3 years to evaluate response patterns of the temperature sensitivities of community phenological sequences to warming (transferred downward) and cooling (transferred upward) along four elevations on the Tibetan Plateau. We found that the temperature sensitivities of flowering stages had asymmetric responses to warming and cooling, whereas symmetric responses to warming and cooling were observed for the vegetative phenological sequences. Our findings showed that coverage changes of flowering functional groups (FFGs; i.e., early-spring FFG, mid-summer FFG, and late-autumn FFG) and their compensation effects combined with required accumulated soil temperatureto codetermined the asymmetric and symmetric responses of community phenological sequences to warming and cooling. These results suggest that coverage change in FFGs on warming and cooling processes can be a primary driver of community phenological variation and may lead to inaccurate phenlogical estimation at large scale, such as based on remote sensing.

Highlights

Climate warming causes a series of ecosystem responses (Walther et al, 2002), including changes in plant phenology (Li et al, 2016; Körner, 2016)
Coverages of earlyspring FFG (ESF) and mid-summer FFG (MSF) were significantly affected by year, donor sites, receptor sites, and most of their interactions (Table 1)
Coverage of the late-autumn FFG (LAF) was only affected by donor site and interaction between year and donor site (Table 1)

Summary

Introduction

Climate warming causes a series of ecosystem responses (Walther et al, 2002), including changes in plant phenology (Li et al, 2016; Körner, 2016). Some studies have found that phenological temperature sensitivities are mismatched at community and species levels (Steltzer and Post, 2009; Wolkovich et al, 2014; Meng et al, 2016; Meng et al, 2017). This mismatch may be caused by divergent responses of different species to warming (Steltzer and Post, 2009; Wolkovich et al, 2014) These studies only consider that warming is the principal factor, ignoring daily or annual frequent temperature fluctuations (Menzel et al, 2011; Kosaka and Xie, 2013). There is little evidence to date on asymmetrical or symmetrical responses to warming and cooling for community phenological sequences

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Discussion

Conclusion