PJ vulnerability

Background

Pinyon-juniper woodlands cover over 100 million acres of the western United States and are the most abundant old-growth and mature forest type, providing extensive ecosystem services and hosting vast biodiversity. Across the wide geographic range of PJ ecosystems, they are experiencing widespread climate-driven declines and are susceptible to ecological transformation (replacement by another ecosystem type).

Land managers have expressed a need for better insights on PJ poulation dynamics under changing climate, and whether management action could reduce PJ declines, but modeling these species has been limited by the quality of inventory data, specifically in difficult to observe juvenile saplings. Successful management of PJ ecosystems would greatly benefit from improved demographic models that quantify how climate change is expected to alter population demographic rates.

Objectives & Approach

This project is focused on modeling how PJ demographic rates (mortality, recruitment, pop. growth) will change under a variety of future climate scenarios. We then place our results in the context of a climate adaptation framework to resist, accept, or direct ecological transformation.

Specifically, we use data from national forest inventory plots (USFS's Forest Inventory Analysis) across the western US combined with a novel demographic model to estimate mortality, recruitment and overall population growth changes in five PJ species.