The devil is in the detail

The devil is in the detail: Nonadditive and context‐dependent plant population responses to increasing temperature and precipitation

Plants marked with toothpicks for demographic study. Picture: Siri Lie Olsen

In climate change ecology, simplistic research approaches may yield unrealistically simplistic answers to often more complicated problems. In particular, the complexity of vegetation responses to global climate change begs a better understanding of the impacts of concomitant changes in several climatic drivers, how these impacts vary across different climatic contexts, and of the demographic processes underlying population changes. Using a replicated, factorial, whole‐community transplant experiment, we investigated regional variation in demographic responses of plant populations to increased temperature and/or precipitation. Across four perennial forb species and 12 sites, we found strong responses to both temperature and precipitation change. Changes in population growth rates were mainly due to changes in survival and clonality. In three of the four study species, the combined increase in temperature and precipitation reflected nonadditive, antagonistic interactions of the single climatic changes for population growth rate and survival, while the interactions were additive and synergistic for clonality. This disparity affects the persistence of genotypes, but also suggests that the mechanisms behind the responses of the vital rates differ. In addition, survival effects varied systematically with climatic context, with wetter and warmer + wetter transplants showing less positive or more negative responses at warmer sites. The detailed demographic approach yields important mechanistic insights into how concomitant changes in temperature and precipitation affect plants, which makes our results generalizable beyond the four study species. Our comprehensive study design illustrates the power of replicated field experiments in disentangling the complex relationships and patterns that govern climate change impacts across real‐world species and landscapes.

Picture on title page

My new paper on trait differentiation and adaptation along elevational gradients is out. And my picture is on the title page!

Abstract

Studies of genetic adaptation in plant populations along elevation gradients in mountains have a long history, but there has until now been neither a synthesis of how frequently plant populations exhibit adaptation to elevation nor an evaluation of how consistent underlying trait differences across species are. We reviewed studies of adaptation along elevation gradients (i) from a meta‐analysis of phenotypic differentiation of three traits (height, biomass and phenology) from plants growing in 70 common garden experiments; (ii) by testing elevation adaptation using three fitness proxies (survival, reproductive output and biomass) from 14 reciprocal transplant experiments; (iii) by qualitatively assessing information at the molecular level, from 10 genomewide surveys and candidate gene approaches. We found that plants originating from high elevations were generally shorter and produced less biomass, but phenology did not vary consistently. We found significant evidence for elevation adaptation in terms of survival and biomass, but not for reproductive output. Variation in phenotypic and fitness responses to elevation across species was not related to life history traits or to environmental conditions. Molecular studies, which have focussed mainly on loci related to plant physiology and phenology, also provide evidence for adaptation along elevation gradients. Together, these studies indicate that genetically based trait differentiation and adaptation to elevation are widespread in plants. We conclude that a better understanding of the mechanisms underlying adaptation, not only to elevation but also to environmental change, will require more studies combining the ecological and molecular approaches.

OpenTraits

The popularity of using traits data in ecology has increased a lot in the last years. Traits can be used to describe species communities across different regions and how they respond to environmental change, and much more.

The goal of OpenTraits is to increase our global knowledge of traits from different organisms by

  • Developing shared data standards;
  • Developing open-source tools and techniques for gathering, cleaning, curating, and analyzing trait data;
  • Developing methods for the prioritization of trait sampling;
  • Increasing collaboration among trait researchers; and
  • Organizing trait sampling efforts for priority regions, taxa and traits.

If you are interested to learn more about OpenTraits, there is a blog post on the Functional Ecologist blog and there will be a workshop prior to the Ecological Society of America annual meetings, New Orleans, Louisiana, USA (August 4-5, 2018).

Working and Learning in a Field Excursion

A colleague has published an article on how biology students learn on field excursions. In addition, to study and learn about nature, these students were themselves being observed by Torstein Nielsen Hole, currently a PhD candidate at bioceed, university of Bergen.

For this study he joined a field course on Svalbard. It’s interesting to read about how biologists discuss their work in the field. And the article covers all from bare soil, death and guns (protection from polar).