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Morning Session
Cumberland Room, 1st Floor

Session Co-Chairs:

• Sarah Nelson, Appalachian Mountain Club
• Rachel Hovel, University of Maine Farmington
• Julia Daly, University of Maine Farmington

Maine encompasses many types of habitats that could be critical to retaining cold conditions as winters warm and shoulder seasons shift toward later autumn and earlier spring. Climate refugia are places on the landscape that remain relatively buffered from changing climate, allowing species and ecosystems to persist. For example, mountain ecosystems develop and retain snow and lake ice more reliably and for longer durations than lower-elevation counterparts. In addition to elevation gradients, significant climate variability from coastal to northern and inland locations, and the effect of microclimate features, can produce cold climate refugia at different scales. In this session, we invite presentations related to climate refugia, trends and patterns in winter or dormant season processes, scale and connectivity of climate conditions, and novel approaches to maintaining or creating cold refugia. The session will open with an invited presentation regarding how climate change refugia conservation can help Maine’s ecosystems. Talks that cover freshwaters and forest ecosystems will follow.

Additional information for this session will be posted shortly.

Session Overview

• 8:30AM-9:00AM — How climate change refugia conservation can help Maine’s ecosystems. Toni-Lyn Morelli
• 9:00AM-9:30AM — Maritime climate and the forests of coastal Maine. Jay Wason
• 9:30AM-10:00AM — Integrated riverscape assessment and restoration opportunity identification including focus on thermal refugia to support recovery of native salmonids. Michael Burke, Keith Kantack
• 10:00AM-10:30AM — Lake phenology across the landscape and climate change refugia. Julia Daly

Session Presentations

Presenters are indicated in bold.

8:30AM – 9:00AM

How climate change refugia conservation can help Maine’s ecosystems

Toni-Lyn Morelli
Department of Environmental Conservation, University of Massachusetts Amherst

As Maine’s species, ecosystems, and livelihoods are threatened by extreme weather and warming lands and waters, researchers and resource managers look to solutions. Climate adaptation focuses on conducting and translating research to minimize the impacts of climate change, including threats to biodiversity and human welfare. One adaptation strategy is to focus on climate change refugia, areas that remain relatively buffered from contemporary climate change over time and enable persistence of valued physical, ecological, and socio-cultural resources. Refugia conservation offers some hope of maintaining current conditions, at least in some places and in the short term. In Maine in particular, there have been ground-breaking partnerships among management agencies and scientists, exploring how on-the-ground action can increase the persistence of the species and landscapes that define Maine. This talk will highlight examples, focused on maintaining snow and forests and moose and songbirds, that show how Maine has been at the leading edge of shepherding this aspect of sustainability.

9:00AM – 9:30AM

Maritime climate and the forests of coastal Maine

Jay Wason¹, Xinyuan Wei¹, Sean Birkel², Daniel Hayes¹, Peter Nelson³, Colby Bosley-Smith¹, Shawn Fraver¹, Rose Gellman⁴, Megan Grega¹, Emily MacDonald¹, Gregory McHale¹, Nicole Rogers⁵, Camilla Seirup⁶
1. University of Maine School of Forest Resources
2. University of Maine Climate Change Institute and Cooperative Extension
3. Laboratory of Ecological Spectroscopy
4. Smokey House Center
5. Maine Forest Service
6. National Park Service

The Gulf of Maine is one of the fastest warming places in North America, threatening the future of its coastal forest ecosystems. Spruce-fir forests exist further south of their typical range along the coast and depend on historically cool and moist conditions. However, we need to know more about where these climate refugia exist to inform sustainable management and conservation decision making. In this study, we used a spatial analysis of climate and forest data to identify the climate indicators that characterize this coastal region and compared a set of machine-learning clustering models to define new climate zones to inform regional forest management and conservation. We found that a model including seasonal indicators of extreme temperature, vapor pressure deficit (VPD; dryness of the air), and precipitation delimited zones along the coast of the Gulf of Maine that best matched the distribution of spruce and fir trees. These new climate zones can now be used to prioritize conservation and management decisions for this highly vulnerable forest type.

9:30AM – 10:00AM

Integrated riverscape assessment and restoration opportunity identification including focus on thermal refugia to support recovery of native salmonids

Michael Burke, Keith Kantack
Interfluve

Following multiple decades of habitat connectivity barrier identification, inventory, prioritization, and mitigation, significant gains in habitat connectivity have been realized in many Maine riverscapes that critical to the recovery of native salmonids. Although naturalized, the riverine habitats that these fish return to lack diversity, richness, and quality, have impaired water quality regimes (in particular water temperature) during critical survival bottlenecks, and are often unable to overcome their degraded quality under present hydrological and sedimentary regimes. The emerging next phase of recovery in Maine requires increased direct action to improve the quality of riverscape habitats, yet the scale of the endeavor is daunting in the shadow of the magnitude of past impacts and degradation, and the expanse of the affected geography. Hence, strategic identification of the most impactful restoration actions will be critical to achieve measurable gains within limited timeframes and resources, and to effectively apply restoration funding efficiently as it becomes available. This presentation describes methods that result in streamlined assessment of geomorphic and habitat condition, identification of riverscape status and trajectory, synthesis of limiting factors, and identification project-scale restoration opportunities in an integrated process. This technique utilizes streamlined assessment protocols adapted from standard protocols and leverages multiple decades of applied restoration design and implementation experience to result in coupled opportunity identification including those targeting thermal refugia, which is a distinguishing improvement over other assessment protocols. The streamlined methods lead to more efficient identification of prioritized restoration actions when applied at the watershed, sub-watershed, or reach scale.

10:00AM – 10:30AM

Lake phenology across the landscape and climate change refugia

R. Hovel¹, J. Daly¹, S. Nelson², S. Dykema³, A. Gavin⁴
1. University of Maine at Farmington
2. Appalachian Mountain Club
3. Alder Environmental
4. University of Maine

Research on climate change refugia in aquatic systems frequently emphasizes cold-water habitats and resistance to increasing temperature. Higher-elevation locations are often identified as important for preserving conditions suitable for cold-water organisms or communities. However, this concept remains understudied in lentic compared to lotic systems, even as lakes variably experience pronounced climate-related impacts including ice loss and higher temperatures. Lake responses to climate depend on characteristics such as landscape position, but the role of elevation is not well-documented and associated biological responses are unclear. Here, we describe spring ice and thermal dynamics in small remote lakes in Maine, USA, ranging from 76 to 955 m above sea level, and how temperature influences zooplankton phenology and community composition. Ice persisted on average 8 days longer in high-elevation (>500 m) lakes and, after ice breakup, high-elevation lakes warmed faster (0.3ËšC/day) than low-elevation lakes (0.2ËšC/day), and reached maximum temperatures 45 days earlier on average. Zooplankton phenology was driven by water temperature, but zooplankton taxa varied in response to lake conditions, shaping different zooplankton assemblages in high- and low-elevation sites. This suggests that refugial high-elevation lakes with prolonged ice and cold spring conditions could present an important regional conservation priority.

Chair Bios

Dr. Sarah Nelson is Director of Research at the Appalachian Mountain Club. Her research focuses on understanding the effects of atmospheric pollution and climate change on forests, foodwebs, and freshwaters in remote and protected ecosystems. Current research includes geochemistry in lakes, climate change–especially snow and changing winter, and mercury contamination. Approaches include long-term monitoring, biosentinels, and citizen/community science at sites across Maine and the Northern Forest, mountain ponds, and national parks around the U.S. 

Dr. Rachel Hovel is an aquatic ecologist whose work focuses on environmental and organismal diversity, phenology, and ecosystem response to change across scales. Her work is motivated by informing decision-making for conservation and landscape resilience, and local projects include better understanding impacts of regional change in high-elevation lakes and watersheds of the Northern Appalachian Mountains. She is an Associate Professor of Biology at the University of Maine-Farmington. 

Dr. Julia Daly is a geologist with an interest in the intersection of landscape evolution, climate change, and human activity. In 2010, she began investigating the response of mountain lakes to shifting climate in western Maine. She is a Professor of Geology at the University of Maine – Farmington.