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Managers need information about the vulnerability of historical plant communities, and their potential future conditions, to respond appropriately to landscape change driven by global climate change. We model the climate envelopes of plant communities on the Kenai Peninsula in Southcentral Alaska and forecast to 2020, 2050, and 2080. We assess 6 model outputs representing downscaled climate data from 3 global climate model outputs and 2 representative concentration pathways. We use two lines of evidence, model convergence and empirically measured rates of change, to identify the following plausible ecological trajectories for the peninsula: (1.) alpine tundra and sub-alpine shrub decrease, (2.) perennial snow and ice decrease, (3.) forests remain on the Kenai Lowlands, (4.) the contiguous white-Lutz-Sitka spruce complex declines, and (5.) mixed conifer afforestation occurs along the Gulf of Alaska coast. We suggest that converging models in the context of other lines of evidence is a viable approach to increase certainty for adaptation planning. Extremely dynamic areas with multiple outcomes (i.e., disagreement) among models represent ecological risk, but may also represent opportunities for facilitated adaptation and other managerial approaches to help tip the balance one way or another. By reducing uncertainty, this eclectic approach can be used to inform expectations about the future. [ABSTRACT FROM AUTHOR]

Rapidly changing environmental conditions are influencing distributions of wildlife species in Alaska. Due to strict physiological requirements, the distribution of American martens (Martes americana) is theorized to be driven by changing habitat, climate, and other anthropogenic conditions. We aimed to quantify marten distributions on the Kenai Peninsula, Alaska, and compared historic and contemporary occurrence records. To illustrate changing distribution patterns, we developed predictive niche models for 2 decades and investigated patterns by relating environmental trends with predicted distributions. Museum and trapping records, supplemented by aerial videography detections for martens on the Kenai over the past century, served to train Random Forests based niche models for 1988-2001 and 2002-2010. Change-detection analyses revealed an ongoing westward expansion of likely marten distribution on the Kenai Peninsula since at least 1988, and historic records indicated longer-term growth. Top predictors in the models included soil ecotype, landcover, distance to trails, and distance to recreation sites. Our research suggests that on the Kenai Peninsula, marten distribution is responding to a combination of landscape and climate effects that have contributed to expanding marten distributions over the past century. [ABSTRACT FROM AUTHOR]

Alaskan boreal forests frequently suffer from outbreaks of bark beetles and fires, factors that appear to combine to alter charcoal production. Charcoal (black carbon) production in forest ecosystems is an important pathway to clarify for a more complete understanding of the effects of fire on carbon cycling in boreal forests. In this study, we aimed to clarify the effects of prevalent outbreaks of the spruce beetle, Dendroctonus rufipennis (Kirby), on charcoal production during forest fires in boreal forests. Snags with prefire damage by the spruce beetle (infested snags) have significantly more charcoal than those undamaged before fire (noninfested snags). This increased amount of charcoal in spruce beetle-damaged trees was probably the result of dried biomass in the canopies of these trees. The results of this study suggest that with changing environmental conditions, the proliferation of insect damage in the boreal forest can modify the effects of fire on carbon sink via a change in the amount of charcoal production. [ABSTRACT FROM AUTHOR]

Klein et al. (2005, Can. J. For. Res. 35: 1931-1941) compare aerial photographs and report dramatically lower lake levels on the northern Kenai Peninsula, Alaska. They hypothesize that the lower lake levels may be caused by a decline in moisture surplus driven by climate change. However, the reported decline in surplus appears to be insufficient to explain the lower lake levels. Here I develop a simple sensitivity analysis to test their hypothesis and also show how tectonic processes such as the Great Alaskan earthquake could dramatically lower lake levels by fracturing an underlying aquitard. Tectonic processes, therefore, could potentially alter forest succession and wetland ecosystems by inducing hydrologic changes that mimic changes in climate. Klein et al. (2005, Rev. Can. Rech. For. 35: 1931-1941) comparent des photographies aériennes et rapportent une baisse dramatique du niveau des lacs dans le nord de la péninsule de Kenai en Alaska. Ils ont émis l'hypothèse que la baisse du niveau des lacs pourrait être due à une réduction de l'excédent d'humidité causée par le changement climatique. Cependant, la diminution de l'excédent d'humidité qui a été rapportée semble insuffisante pour expliquer la baisse du niveau des lacs. Dans cet article, j'élabore une simple analyse de sensibilité pour tester leur hypothèse et je montre comment des processus tectoniques, tels que l'important tremblement de terre de 1964 en Alaska, auraient pu causer une baisse dramatique du niveau des lacs en fracturant une couche semi-perméable souterraine. Des processus tectoniques pourraient par conséquent modifier la succession forestière et les écosystèmes des zones humides en induisant des changements hydrologiques qui imitent des changements climatiques. [ABSTRACT FROM AUTHOR]