Natural complexity and the scientists’ responsibility

I just came back from a week of backpacking in the Gila Wilderness. I hiked from the hot New Mexico desert into cool moist canyons lush with blooming yellow Columbines and omnipresent poison ivy all the way to cool dry peaks where firs, pines and aspen formed healthy green forests. In places, wildfires have killed trees whose boles will retain the stored carbon for years to come providing great drumming opportunities for the local woodpeckers and flickers. We discover these while pitching our tent under a patch of remnant green trees in a large burn area.

Regeneration is obvious everywhere and young aspens illuminate the trail with their white bark and fluttering bright green leaves while small evergreen seedlings sprout underneath. I see remnants of snow on north facing hills, in dark places under large rocks, snow left over from this cold wet winter that has all the springs gushing.

Fresh feces from bears, bobcats, elk, deer are everywhere on the trails. Trail maintenance is limited and I have to climb over many downed logs, survive many stream crossings, while admiring the magnificent old growth trees standing along the trail. Butterflies of all colors flutter around us every day. We refresh ourselves in crystal clear streams where nice trout taunt my fisherman husband who left his fishing rod at home. A beautiful healthy wilderness.

I did this hike following a week of meeting where scientists had gathered to discuss climate change impacts on mountain flora and fauna. 110 scientists met in western Oregon where record cool temperatures occurred this spring. After many very interesting talks, the message I gathered was: mountains are complex systems and projections of future climate are not up to the task of telling us enough about the interactions between complex topography and vegetation dynamics to conclude with certainty about extirpations of existing species for example. Climate change will definitely impact the alpine systems but it behooves us to look, to monitor, to watch and understand how natural processes operate, when physiological thresholds are passed, and how organisms deal with various types of disturbance.

As we observe increases in mortality and habitat shifts in certain areas, it is too simple to just point to large-scale temperature changes, to use colorful maps to indicate “refugia” where models agree and doom and gloom where they disagree.

Deep western valleys allow inversions and cold air ponding, shaded riparian corridors like the steep New Mexico canyons allow plants and animals to remain cool and moist, both causing an obvious decoupling from the regional warming. Animals like pikas move up and down through the talus rocks avoiding cold by diving in or gathering heat by reaching the surface of rock piles, adjusting their behavior seasonally. Just like rattlesnakes will avoid the peak of the heat during the day, animals adapt their behavior or sometimes their morphology to fit the climate they are subjected to.

We need to remain aware of the complexity of the landscape we study. We need to see more, to understand more, to ultimately build more reliable models that can help us extrapolate from our observations and be more aware of what the future might have in store for us. Things are changing but we are so focused on developing new technology that we forget models are only as good as the assumptions scientists have built in them and the parameter values programmers have picked from more or less recent published papers.

One of the meeting speakers showed us maps reflecting the admirable patchiness of alpine meadow mammal encounters concluding we had to be really careful about talking about extinction, that other options might be possible in these complex alpine environments. I thought of that patchiness as I looked at the interdigitation of forest types high in the Gila. Wildfires have been the main drivers of this striking mosaic of species assemblages. And the forest has responded with new trees, shrubs, new seedlings, new animals using this evolving system. Nature is complex.

Before we decide we need more genetic manipulations or assisted migrations, we need to think that we may not be the wizards we think we are. Old naturalists spent a lot of time observing and describing. Today’s land stewards hold knowledge that is invaluable to prepare for the future.

One speaker concluded his talk by saying we needed a stronger conceptual foundation as our technical focus was outstripping our conceptual basis. Climate modelers have done a great job building models based on state of the art knowledge of how we understand our planet is working but there are still plenty of unknowns.

 The ball is squarely in the ecologists’ court to observe and understand what is happening, how organisms respond to the changes we are measuring. We need to be careful and not use decade old theories from laboratory experiments about how plants and animals function. Adaptation is an on-going process in nature that has never ceased to occur. Even humans in history adapted their behavior, their food choices, and the shape of shelters to the local climate, the local conditions. Our society is always ready for quick action and technological fixes.

As we see in the Gulf of Mexico, technology can fail us. It would behoove us all to go back to the field, to pay attention to systems’ responses to the many types of on-going disturbances, to watch, to note and describe how we think we understand these systems are changing. It is the challenge of today’s scientists. Computers are great tools but behind it all we need to base our work on a solid understanding of biological processes.

A colleague used to gloat “who needs data when you have a good model”. As things change and model assumptions become obsolete, only the data we collect and the appreciation of the myriad connections between system components and environmental drivers can inform the thinkers of today. They might then develop strategies for our society to survive the on-going disturbances it brings to our planet. As John Muir used to say: “In every walk with nature one receives far more than he seeks.”