Antagonistic biotic interactions mitigate the positive effects of warming on wood decomposition.

Global change drivers such as habitat fragmentation, species invasion, and climate warming can act synergistically upon native systems; however, global change drivers can be neutralized if they induce antagonistic interactions in ecological communities. Deadwood comprises a considerable portion of forest carbon, and it functions as refuge, nesting habitat and nutrient source for plant, animal and microbial communities. We predicted that thermophilic termites would increase wood decomposition with experimental warming and in forest edge habitat.

A framework for localizing global climate solutions and their carbon reduction potential.

Localized carbon reduction strategies are especially critical in states and regions that lack top-down climate leadership. This paper illustrates the use of coupled systems in assessments of subnational climate solutions with a case study of Georgia, a state located in the southeastern United States that does not have statewide climate goals or plans. The paper illustrates how robust place-specific plans for climate action could be derived from foundational global and national work and by embedding that research into the context of socio-ecological-technological systems.

Translating a Global Emission-Reduction Framework for Subnational Climate Action: A Case Study from the State of Georgia.

Subnational entities are recognizing the need to systematically examine options for reducing their carbon footprints. However, few robust and comprehensive analyses are available that lay out how US states and regions can most effectively contribute. This paper describes an approach developed for Georgia-a state in the southeastern United States called "Drawdown Georgia", our research involves (1) understanding Georgia's baseline carbon footprint and trends, (2) identifying the universe of Georgia-specific carbon-reduction solutions that could be impactful by 2030, (3) estimating the greenhouse gas reduction potential of these high-impact 2030 solutions for Georgia, and (4) estimating associated costs and benefits while also considering how the solutions might impact societal priorities, such as economic development opportunities, public health, environmental benefits, and equity.

Root standing crop and chemistry after six years of soil warming in a temperate forest.

Examining the responses of root standing crop (biomass and necromass) and chemistry to soil warming is crucial for understanding root dynamics and functioning in the face of global climate change. We assessed the standing crop, total nitrogen (N) and carbon (C) compounds in tree roots and soil net N mineralization over the growing season after 6 years of experimental soil warming in a temperate deciduous forest in 2008. Roots were sorted into four different categories: live and dead fine roots (≤1mm in diameter) and live and dead coarse roots (1-4 mm in diameter).

Thermal adaptation of soil microbial respiration to elevated temperature.

In the short-term heterotrophic soil respiration is strongly and positively related to temperature. In the long-term, its response to temperature is uncertain. One reason for this is because in field experiments increases in respiration due to warming are relatively short-lived.

Long-term CO2 enrichment of a forest ecosystem: implications for forest regeneration and succession.

The composition and successional status of a forest affect carbon storage and net ecosystem productivity, yet it remains unclear whether elevated atmospheric carbon dioxide (CO2) will impact rates and trajectories of forest succession. We examined how CO2 enrichment (+200 microL CO2/L air differential) affects forest succession through growth and survivorship of tree seedlings, as part of the Duke Forest free-air CO2 enrichment (FACE) experiment in North Carolina, USA. We planted 2352 seedlings of 14 species in the low light forest understory and determined effects of elevated CO2 on individual plant growth, survival, and total sample biomass accumulation, an integrator of plant growth and survivorship over time, for six years.

Elevated CO2 reduces leaf damage by insect herbivores in a forest community.

By altering foliage quality, exposure to elevated levels of atmospheric CO(2) potentially affects the amount of herbivore damage experienced by plants. Here, we quantified foliar carbon (C) and nitrogen (N) content, C : N ratio, phenolic levels, specific leaf area (SLA) and the amount of leaf tissue damaged by chewing insects for 12 hardwood tree species grown in plots exposed to elevated CO(2) (ambient plus 200 microl l(-1)) using free-air CO(2) enrichment (FACE) over 3 yr. The effects of elevated CO(2) varied considerably by year and across species.

Net primary production of a forest ecosystem with experimental CO2 enrichment.

The concentration of atmospheric carbon dioxide was increased by 200 microliters per liter in a forest plantation, where competition between organisms, resource limitations, and environmental stresses may modulate biotic responses. After 2 years the growth rate of the dominant pine trees increased by about 26 percent relative to trees under ambient conditions. Carbon dioxide enrichment also increased litterfall and fine-root increment.