Transplants, Open Top Chambers (OTCs) and Gradient Studies Ask Different Questions in Climate Change Effects Studies

• Published in: Frontiers in Plant Science
• Main Authors: Yang, Yan, Halbritter, Aud H., Klanderud, Kari, Telford, Richard J., Wang, Genxu, Vandvik, Vigdis
• Format: Article in Journal/Newspaper
• Language: English
• Published: FRONTIERS MEDIA SA 2018
• Subjects: alpine grasslands; experimental warming; integrated approaches; space-for-time; southwestern China; PLANT COMMUNITY RESPONSES; WARMING EXPERIMENTS; INTEGRATED APPROACH; VEGETATION CHANGE; SPECIES RICHNESS; TEMPERATURE; ECOSYSTEMS; MANIPULATIONS; DIVERSITY; PATTERNS; Plant Sciences; Arctic; Climate change
• Online Access: http://ir.imde.ac.cn/handle/131551/24231; https://doi.org/10.3389/fpls.2018.01574

Long-term monitoring, space-for-time substitutions along gradients, and in situ temperature manipulations are common approaches to understand effects of climate change on alpine and arctic plant communities. Although general patterns emerge from studies using different approaches, there are also some inconsistencies. To provide better estimates of plant community responses to future warming across a range of environments, there have been repeated calls for integrating different approaches within single studies. Thus, to examine how different methods in climate change effect studies may ask different questions, we combined three climate warming approaches in a single study in the Hengduan Mountains of southwestern China. We monitored plant communities along an elevation gradient using the space-for-time approach, and conducted warming experiments using open top chambers (OTCs) and plant community transplantation toward warmer climates along the same gradient. Plant species richness and abundances were monitored over 5 years addressing two questions: (1) how do plant communities respond to the different climate warming approaches? (2) how can the combined approaches improve predictions of plant community responses to climate change? The general trend across all three approaches was decreased species richness with climate warming at low elevations. This suggests increased competition from immigrating lowland species, and/or from the species already growing inside the plots, as indicated by increased biomass, vegetation height or proportion of graminoids. At the coldest sites, species richness decreased in OTCs and along the gradient, but increased in the transplants, suggesting that plant communities in colder climates are more open to invasion from lowland species, with slow species loss. This was only detected in the transplants, showing that different approaches, may yield different results. Whereas OTCs may constrain immigration of new species, transplanted communities are rapidly exposed to new neighbors that ...