Damage caused by the Mountain Pine Beetle in E. C. Manning Provincial Park, British Columbia, Canada (Photo credit: Wikipedia) I think I’ve found a gem in the Naturalist Nights Series hosted by the Aspen Center for Environmental Studies (ACES). These interesting and entertaining presentations are held on Thursday evenings at their Hallam Lake location in Aspen, Colorado.
Last week's lecture, “The Future Forest: Understanding our Forests and Efforts to Protect Them”, was presented by Dr. Tony Cheng, PhD, Director of the Colorado Forest Restoration Institute at Colorado State University (CFRI).
CFRI’s mission is “to develop, compile, and apply the most current natural and social scientific information relevant to the needs of forest managers and communities in taking action to mitigate wildfire risk and restore healthy forest conditions and to “encourage the collaborative, science-based ecosystem restoration of priority forest landscapes”. The institute works locally with such organizations as the Colorado Bark Beetle Cooperative .
Dr. Cheng introduced the concept of resilience and described normal wildfire activity and healthy forest conditions using the Panarchy and the Resiliency Cycle outlined by Lance H. Gunderson and C. S. Hollings. This framework suggests that most ecological systems are governed by a repeating cycle comprised of four elements: exploitation; conservation; release (also termed “creative destruction,”); and reorganization.
Resilience may be defined as “the capacity of a system to absorb disturbance and reorganize while undergoing change so as to still retain essentially the same function, structure, identity, and feedbacks.” - http://www.resalliance.org/index.php/glossary .
The related Resiliency Cycle phases may be generally defined as:
- Exploitation : vegetation uses the soil resources to grow and mature
- Conservation : older, mature growth builds up and stores biomass
- Release : The freeing of the nutrients stored in the biomass as a result of natural or man-made disturbances (anticipated or unexpected) to an ecosystem. See Disturbance regime below.
- Reorganization : Nutrients freed by a release become available to be used in the next exploitation phase to produce a similar or different ecosystem.
- Disturbance regime : “ the pattern of disturbances that shape an ecosystem over a long time scale .” ( www.eoearth.org ) Examples of these disturbances are: fire; flood; disease; insect infestation; wind; avalanches; mining; and logging.
According to Dr. Cheng, we are currently seeing “large scale releases” due, in part to the forest management polices of the last 100 years. In light of this, “In Colorado, numerous initiatives are being undertaken to restore forest ecosystems that have been degraded through past management policies and practices.” ( http://aspennature.org/taxonomy/term/47/all?page=3 )
One major consideration with these initiatives is that currently there are not enough resources to restore all forests regions that might require it, therefore decisions must be made as to which forest zones and areas have the highest restoration need. A guiding principle is that forest restoration is warranted when the science (ecological need) and human values coincide.
According to Dr. Cheng, the forests around Aspen fall primarily into three ecological zones, the Lower Montane, the Upper Montane and Subalpine. Elevation ranges for the zones vary depending on several factors, but generally in the Aspen area the three zones appear to range from roughly 6,000 ft. to about 11,500 ft.
The Lower Montane zone is relatively hot and dry, has a high ecological need for restoration and is home to a lot of people. Therefore, the convergence of the scientific evaluation and the societal considerations indicate a high need for restoration.
The Upper Montane zone is generally more diverse and complex, is cooler and wetter, and is not as heavily inhabited by humans. Because of these characteristics, the restoration need for this zone is rated low to moderate. However, if projected climate changes occur, some think that it is likely that this zone will become warmer and drier (more like the current Lower Montane zone) and the ecological need for restoration will most likely increase.
The Subalpine zone is higher, cooler and wetter. This is generally where the ski areas are. These areas experience “infrequent but high disturbances” and have the least human habitation; and at the moment, it has been determined that they have no ecological restoration need.
Given the above relative restoration need assessments, restoration focus is presently on the Lower Montane zone, and one of the main issues of disturbance concern locally is mountain pine beetle infestation.
Dr. Cheng suggested that, contrary to what some have said, the mountain pine beetle infestation has perhaps actually resulted in net benefits to forest health by helping to increase diversity and therefore its potential resilience. This continues to be evaluated.
In closing, we were left with these concepts to consider:
- Appreciate diversity in the forests for its value in maintaining the health of our ecosystems
- Government agencies, schools, organizations, and individuals need to learn together in order to protect our forests
- We need to rely on and help organizations like ACES to inform the public as to what is going on
- We need to continue monitoring the trends
- We need to prioritize the high restoration need areas
The next Naturalist Nights Series presentation, "Climate Change and Our Future in the Rocky Mountains", will be Thursday, March 22nd at the Aspen Center For Environmental Studies – 7:30 PM.
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