Resilience Ecology in a changing world

Door prize winner Jean Patton and Don Falk; photo by Ed Skaff

Door prize winner Jean Patton and Don Falk; photo by Ed Skaff

Pam Boedeker

SaddleBrooke Nature Club has again benefitted from the incredible speakers, research and resources about our desert environment at the University of Arizona. Our speaker at the November meeting was Dr. Don Falk. He is on the faculty at the University of Arizona teaching a class on Watershed Management and Ecohydrology. His research areas include fire history, fire ecology, restoration ecology, landscape ecology, the impacts of land management and global change on ecosystems. Don is also a renowned tree ring biologist.

According to Dr. Falk, SaddleBrooke Nature Club has earned a reputation with University of Arizona speakers for being an inquisitive, knowledgeable and skeptical audience. This was particularly significant to him as his presentation would frequently reference climate change.

Don was among the scientists who participated in The World Economic Forum. The economists listed failure to adapt to climate change as one of the most serious problems that would affect the world economy.

Dr. Falk and other researchers look at both precipitation and temperatures over time to predict future patterns that will affect our environment. Precipitation is variable and thus a less reliable source of data. Changes in temperatures, especially in the Arctic regions, are better indicators for scientists.

Don is associated with the Tree Ring lab at the University of Arizona. Tree rings can reveal 1,000 plus years of information. In the Southwest, Don explained, they look to winter (not monsoon) precipitation, seasonal temperatures and how dry the air is. There have been five significant droughts in the Southwest including our current drought. (The good news according to Don is that there are signs we may be coming out of the drought!)

The bad news is that over time our climate will become inhospitable for forests. Our trees are showing signs of chronic stress.

Wild fires are a natural component of maintaining a healthy tree population. Man has altered that pattern by extinguishing those natural fires and not allowing scrub trees and brush to be reduced. The larger, more productive trees’ source of light and nutrients are limited. From the 1990s to present fires have grown to ten times the size they used to be! Our fire season has grown to be year round.

Our eco system has magnificent capacity to recover from major disturbances such as wild fire. For example, a forest of conifers might be destroyed by fire. In their place a forest of Gambel Oak will grow.

These trees take less water but they also absorb less carbon.

Nature has a plan for reorganization. There are practices humans can adopt to assist and encourage this reorganization. The field is called Restoration Ecology. Before and after photos were shown from Spain, Costa Rica, India and South Africa. Scientists and locals are learning to help nature heal itself.

The message Dr. Falk left us with is that there will be change but we can prepare for it and assist nature in adapting to that change.

A thought-provoking question and answer session followed Don’s presentation.