Climate Change for the Southern Coastal Plain

James M. Vose

Center for Integrated Forest Science USDA Forest Service

Southern Research Station

Today’s Talk….

• Overview and summary of potential changes

in climate for the coastal plain • Discussion of direct and indirect effects • Introduction to potential impacts and

vulnerabilities

Direct effects o Warming o Changing precipitation (amount and extremes) o Elevated CO2 o Sea level rise

Indirect effects o Fire o Insects and pathogens o Invasive species

Combined effects, stress complexes

Climate change effects on SE Coastal Plain forests

Changing Forests…Enduring Values

Updated Climate Projections

Future climate Temperature Precipitation

Changing Forests…Enduring Values

From Kunkel et al. (2013)

Temperature Precipitation

warmer wetter or drier

Changes are predicted to impact species….

….and processes

Lockaby et al. 2011

less

more

Extremes may be more important than changes in the mean

Climate Variability & Extremes

Drought severity will increase

Changing Forests…Enduring Values

From Burke et al. (2006) …the “hotter drought” (Millar and Stephenson 2015)

Clark et al. 2016 (Chapter 4)

DROUGHT in the SE Coastal Plain

Projected Keetch-Byram drought index, based on temperature and precipitation changes for the end of the 21st century

Orange-red colors indicate areas with highest fire potential

Projected wildfire potential

Changing Forests…Enduring Values

Data from Liu et al. (2010)

Winter

Autumn Summer

Spring

Insects and Pathogens

Kolb et al. (2016)

Invasives?

Interactions of multiple stressors will accelerate with higher temperature and more droughts

Stress complexes for upland and coastal forests in the southern U.S.

Stress complexes will be affected by a warmer climate

Changing Forests…Enduring Values

From Don McKenzie

Understanding and Managing Forests in the Face of Climate Change

Challenges: • Responses to novel and extreme conditions

– Biological – Physical

• Multiple, co-occurring stresses (complexes)

Impacts and Vulnerabilities

Forests are adapted to climate variation and composition, structure, and function has been shaped by historical and contemporary climate and disturbance regimes

• varies among species and ecosystems • management has and can shape resilience and

resistance

Impacts and Vulnerabilities Forests in many areas in the eastern US are changing in response to recent climate trends and new disturbance regimes…

McEwan et al. 2011

• mesophication of eastern hardwood forest • altered vulnerability to future climatic conditions pine plantation vs. hardwood • more susceptible to threshold responses?

Elliott and Vose 2011

(Klos et al. 2009)

Fig. 2. Mean annual mortality rates by drought class for the (a) pine, (b) oak, and (c) mesophytic species groups. For each species group, the results of the least significant difference test are indicated with letter designations shown above each bar. Significant differences were determined using a P value of 0.05.

Millar and Stephenson (2015)

How will SE Coastal Forest Ecosystems Respond to New Disturbance Regimes?

Can we manage forests to change thresholds or keep ecosystem services once thresholds are crossed? Manage “mega-disturbance” occurrence? Manage “mega-disturbance” impacts by…. Managing species? Managing genetics? Managing structure?

Clark et al. (2016)

Manage Impacts?

Conclusions

• Predicting climate futures are uncertain, but most models predict hotter and drier – the “hot drought”

• Forests are already being impacted by these environmental conditions (lower growth; higher mortality)

• It’s complicated – stresses are usually not individual, but rather a combination of stressors

Conclusions

• These stress complexes may create conditions that “tip” forests to new states – these may be undesirable

• Management intervention may be required to

change the tipping point and/or minimize impacts on ecosystem services.