Thursday, August 20, 2009

Olympic National Park

Isabel and Micah ascending the world's largest Sitka spruce.

The family and I are on vacation in the Olympic Peninsula of Washington. We’ve spent the past three days at Lake Quinalt, which is on the southwest side of mountains and surrounded by temperate rainforest. A few things struck me while here. First, 15 feet of rain (the record annual precipitation) is a lot, but it can be hot and dry here. Second, it would have been wise to have bought a cooler and fast on smoothies for three days. There are few places to eat around here, especially since we are going back to Seattle to eat at places like Salumi and Pike Place Market.

The Quinalt River Valley has six record trees in it. The world’s largest western red cedar, Douglas fir, mountain hemlock, and Sitka spruce, are all in the one valley. The western red cedar is 19.5 feet across. It’s hollow in the middle and you can see daylight when you look up from within. I’m not sure where the phloem was, but there were green limbs up high. The Sitka spruce is 17 feet across and aside from being stuck between an RV park and a golf course, is impressive.

As we’ve hiked through the forests here, it has been interesting to think about how these trees have been accumulating environmental records for so long. Tree ring width and carbon and oxygen isotopes are the main records examined, but I’ve been thinking more about the nitrogen isotopes. From work I’ve done with Kendra in the past, every tree potentially has a record of nitrogen availability in its rings. The isotopic ratio of nitrogen stored in wood is largely set down initially and has been shown to track N availability. Only a small number of trees have had the N isotopes in wood measured and for the most part we are ignorant about how N availability has changed in these immense forests or others. It’s an important question since we don’t know how elevated CO2 has affected N availability or how frequently N availability might peak with disturbances, which has important implications for the ecology of these forests.

I am pretty sure we don’t have a 10 foot increment borer in the lab, but there are some long records here just waiting to be read.

Tuesday, August 11, 2009

Ecological Society of America Conference

ESA was in Albuquerque, NM this year. A couple of things stood out.

First, I attended a number of talks about plant traits and performance of species. Very little of the intellectual energy in these talks focused on the relationships among traits or how traits would affect the abundance of species. Instead, most of the energy focused on phylogenetic relationships of species. In some cases, the simplest of traits was overlaid on somewhat complex phylogenies. No one seemed to say species A is more abundant than B because of trait X. Instead, there was more focus on phylogenetic distance of how individual traits changed with evolutionary time. These types of questions are incredibly interesting, but there was almost no balance. The field still seems to be avoiding central questions about traits and abundance.

Second, NSF had put together two days of talks on Coupled Biogeochemical Cycles. The talks were a murderers row of speakers. Members of the National Academy were pushed back to the second day. The talks focused on understanding how coupling different biogeochemical cycles together better helps us understand the functioning of ecosystems in different contexts. For example, coupling the carbon and nitrogen cycles better helps us understand the responses of ecosystems to elevated CO2 than just examining the C cycle. Investigating Ca availability helps us better understand NO3- loss from ecosystems. Not much in any one talk was that novel, but together, the talks provided a great overview for the science. I would have liked to see some questions discussed a bit more. For example, how do researchers choose which elemental cycle to consider when trying to understand a given process? When modeling the global C cycle, should we next incorporate the N cycle? Or P? These are pretty tough questions without roadmaps. Still, the symposia were pretty amazing. It'd be great if NSF could continue to host these multi-day events within ESA.