Predicting Effects of Climate Change on Habitat Suitability of Red Spruce (Picea rubens Sarg.) in the Southern Appalachian Mountains of the USA: Understanding Complex Systems Mechanisms through Modeling

Abstract

Alpine, subalpine and boreal tree species, of low genetic diversity and adapted to low optimal temperatures, are vulnerable to the warming effects of global climate change. The accurate prediction of these species' distributions in response to climate change is critical for effective planning and management. The goal of this research is to predict climate change effects on the distribution of red spruce (Picea rubens Sarg.) in the Great Smoky Mountains National Park (GSMNP), eastern USA. Climate change is, however, conflated with other environmental factors, making its assessment a complex systems problem in which indirect effects are significant in causality. Predictions were made by linking a tree growth simulation model, red spruce growth model (ARIM.SIM), to a GIS spatial model, red spruce habitat model (ARIM.HAB). ARIM.SIM quantifies direct and indirect interactions between red spruce and its growth factors, revealing the latter to be dominant. ARIM.HAB spatially distributes the ARIM.SIM simulations under the assumption that greater growth reflects higher probabilities of presence. ARIM.HAB predicts the future habitat suitability of red spruce based on growth predictions of ARIM.SIM under climate change and three air pollution scenarios: 10% increase, no change and 10% decrease. Results show that suitable OPEN ACCESSForests 2015, 6 1209 habitats shrink most when air pollution increases. Higher temperatures cause losses of most low-elevation habitats. Increased precipitation and air pollution produce acid rain, which causes loss of both low-and high-elevation habitats. The general prediction is that climate change will cause contraction of red spruce habitats at both lower and higher elevations in GSMNP, and the effects will be exacerbated by increased air pollution. These predictions provide valuable information for understanding potential impacts of global climate change on the spatiotemporal distribution of red spruce habitats in GSMNP.

Assessing Climate Change Impact on Forest Habitat Suitability and Diversity in the Korean Peninsula

“…The habitat suitability of a forest can be understood as a concept similar to the potential species distribution of a forest, in that it analyzes the area favorable for plant growth [10][11][12]. Many studies using future climate data that predict changes in forest habitat suitability or species distribution due to climate change have been performed at national and regional levels [13][14][15].…”

“…SDM finds suitable growth areas for the changing environment through the past occurrence data of species. The representative tools for the SDM are maximum entropy (MaxEnt), generalized linear model (GLM), generalized additive model (GAM), and random forest (RF) [11,[16][17][18].…”

Epidemic spruce beetle outbreak changes drivers of Engelmann spruce regeneration

“…However, our results indicated some level of spruce establishment across a range of environmental conditions. In other climatically limited systems, projected increases in temperature are expected to reduce low-elevation habitat (Koo et al 2015). If planning goals include maintaining Engelmann spruce in areas that have not yet been affected by an outbreak, management practices could be focused on creating resilience in terms of promoting advance regeneration-easily achieved through silvicultural treatments (Windmuller-Campione and Long 2015, Windmuller-Campione et al 2017).…”

“…However, if Engelmann spruce is desired in the wake of large outbreaks, where altered regeneration processes have the potential to influence future species composition, post-outbreak microclimate conditions should be considered when planning salvage harvests or planting operations. In other climatically limited systems, projected increases in temperature are expected to reduce low-elevation habitat (Koo et al 2015). However, given adequate soil moisture in monsoon-influenced regions, even lower elevations with high moisture deficit could be suitable habitat for Engelmann spruce seedlings whether regenerated naturally or planted.…”

Using Landsat imagery to map understory shrub expansion relative to landscape position in a mid‐Appalachian watershed

“…Large stands of P. rubens have been replaced by secondary growth forests often consisting of Betula alleghaniensis and Acer rubrum with P. rubens, Tsuga canadensis, and other species playing a less prominent role in the forest, or relegated to isolated mountain tops or sheltered fragments (Allard andLeonard 1952, Abrams andMcCay 1996). Recent efforts have been undertaken to restore P. rubens in potentially suitable areas within the mid-Appalachians and southern Appalachians in an attempt to preserve and expand these fragile ecosystems (Koo et al 2014a, 2014b, Koo et al 2015, Walter et al 2017.…”