U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


Forest Lichens May Suffer Changes in Production and Range with Future Environmental Warming
Published: February 26, 2018
Posted: April 10, 2018

Empirical and modeling approaches were used to assess the response of lichens as an indicator species for change.

The Science
The SPRUCE environmental manipulation experiment funded by DOE was used to study productivity and community composition of arboreal lichens (those living on tree branches) in a warmer future environment.

The Impact
Changing patterns of warming and drying are likely to decrease or reverse tree-based lichen growth at its southern range margins. Negative carbon balances among persisting individuals could commit these epiphytes to local extinction. These findings illuminate fundamental processes underlying local extinctions of epiphytes and suggest broader consequences for range shrinkage if dispersal and recruitment rates cannot keep pace.

Summary
Changing climates are expected to affect the abundance and distribution of global vegetation, especially plants and lichens with an epiphytic lifestyle and direct exposure to atmospheric variation. The study of epiphytes could improve understanding of biological responses to climatic changes, but only if the conditions that elicit physiological performance changes are clearly defined. The team evaluated individual growth performance of the epiphytic lichen Evernia mesomorpha, an iconic boreal forest indicator species, in the first year of a decade-long experiment featuring whole-ecosystem warming and drying. Field experimental enclosures were located near the southern edge of the species' range.

Mean annual biomass growth of Evernia significantly declined 6 percentage points for every +1°C of experimental warming after accounting for interactions with atmospheric drying. Mean annual biomass growth was 14% in ambient treatments, 2% in unheated control treatments, and -9% to -19% (decreases) in energy-added treatments ranging from +2.25 to +9.00°C above ambient temperatures. Warming-induced Biomass losses among persistent individuals were suggestive evidence of an extinction debt that could precede further local mortality events.

Changing patterns of warming and drying would decrease or reverse Evernia growth at its southern range margins, with potential consequences for the maintenance of local and regional populations. Negative carbon balances among persisting individuals could physiologically commit these epiphytes to local extinction. These findings illuminate the processes underlying local extinctions of epiphytes and suggest broader consequences for range shrinkage if dispersal and recruitment rates cannot keep pace.

Contacts (BER PM)
Daniel Stover
Terrestrial Ecosystem Science, SC-23.1
Daniel.Stover@science.doe.gov (301-903-0289)

(PI Contact)
Paul J. Hanson
Environmental Sciences Division, Oak Ridge National Laboratory
hansonpj@ornl.gov

Funding
This material is based on work supported by the US Department of Energy, Office of Science, Office of Biological and Environmental Research. Oak Ridge National Laboratory (ORNL) is managed by UT Battelle, LLC, for the US Department of Energy under contract DEAC05-00OR22725. The SPRUCE experiment is a collaborative research effort between ORNL and the USDA Forest Service.

Publications
Smith, R.J., P.R. Nelson, S. Jovan, P.J. Hanson, and B. McCune. "Novel climates reverse carbon uptake of atmospherically-dependent epiphytes: climatic constraints on the iconic boreal forest lichen Evernia mesomorpha." American Journal of Botany 105, 266-274 (2018). [DOI:10.1002/ajb2.1022]

Related Links
Spruce and Peatland Responses Under Changing Environments project

Topic Areas:

  • Research Area: Terrestrial Ecosystem Science
  • Research Area: Spruce and Peatland Responses Under Changing Environments (SPRUCE)

Division: SC-23.1 Climate and Environmental Sciences Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]

Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]

Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]

Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]

Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]

List all highlights (possible long download time)