Predicting effects of climate change on productivity and persistence of forest trees

Abstract

Global climate change increases uncertainty in sustained functioning of forest ecosystems. Forest canopies are a key link between terrestrial ecosystems, the atmosphere, and climate. Here, we introduce research presented at the 66th meeting of the Ecological Society of Japan in the symposium “Structure and function of forest canopies under climate change.” Old‐growth forest carbon stores are the largest and may be the most vulnerable to climate change as the balance between sequestration and emission could easily be tipped. Detailed structural analysis of individual large, old trees shows they are allocating wood to the trunk and crown in patterns that cannot be deduced from ground, thus can be used to more accurately quantify total forest carbon and sequestration. Slowly migrating species sensitive to novel climatic conditions will have to acclimate at the individual level. Accounting for physiological responses of trees to climate change will improve predictions of future species distributions and subsequent functioning of forest ecosystems. Field experiments manipulating temperature and precipitation show how trees compensate physiologically to mitigate for higher temperatures and drought. However, it is difficult to measure acclimation responses over long timeframes. Intraindividual trait variation is proposed as an indicator of acclimation potential of trees to future conditions and suggests that acclimation potential may vary among regional populations within a species. Integrating whole‐tree structural data with physiological data offers a promising avenue for understanding how trees will respond to climatic shifts.

Experimental warming across a tropical forest canopy height gradient reveals minimal photosynthetic and respiratory acclimation

“…This suggests that water‐use efficiency initially increases and then declines at high temperatures, providing further evidence that high leaf temperatures did not initiate transpirational cooling. As such, if T opt is not acclimating to warmer temperatures, the upper canopy leaves could be pushed towards a lower capability for carbon uptake (Kramer et al, 2020; Pau et al, 2018) with large implications for the biosphere's carbon uptake and exchange with the atmosphere.…”

Intra‐crown variation of leaf mass per area of Fagus crenata is driven by light acclimation of leaf thickness and hydraulic acclimation of leaf density

“…Growing conditions are changing quickly relative to the life span of individual trees due to climate change. Phenotypic plasticity can potentially buffer negative effects of future climate change on growth and productivity of individual trees (Kramer et al, 2020). While trait variation within and among individuals of a population has been used to infer phenotypic plasticity, our study suggests the degree of variation depends on traits examined and the extent that populations vary in exhibiting high or low phenotypic plasticity.…”

“…Our results also suggested variation of leaf morphology is largely driven by light acclimation, while anatomical traits like mesophyll porosity appeared to be affected by height‐related hydraulic limitation. Although it is difficult to clarify the critical factor affecting leaf traits based on observational data, comparison of genetic variation and phenotypic plasticity helps us to develop a more comprehensive understanding of how species will fare under future climate conditions and how their distributions might shift in the future (Fritz et al, 2018; Kramer et al, 2020).…”

“…The observed range of intra‐crown leaf trait variation reflects phenotypic plasticity and is regarded as a potential indicator of individual‐level acclimation potential to environmental perturbation (Franks et al, 2014; Kramer et al, 2020; Van Kleunen & Fischer, 2005). Thus, phenotypic plasticity is likely to be an important factor influencing growth and survival of trees under future climate change (Kramer et al, 2020; Nicotra et al, 2010; Valladares et al, 2014).…”

Uncovering the Research Gaps to Alleviate the Negative Impacts of Climate Change on Food Security: A Review

“…Moreover, the demand for fisheries and livestock products is projected Some forest species are expected to become limited due to direct impacts of climate change which ultimately will hinder the economic growth and food security of populations whose incomes are concerned with forest farming. Forest productivity may be basically shifted if especially vulnerable, yet ecologically essential species are lost due to physiological impacts of climatic stresses (Kramer et al, 2020). Direct effects result when climatic variables approach physiological limits of forest and affect tree functioning.…”