Thursday, November 14, 2013

You don't know where you're going until you know where you've been...





Hiking through a powdery layer of snow on a crisp day in early November, moisture for the valley was looking promising for this fall. It was not even Thanksgiving, and the snow was already deep enough to over-top our boots when we went off trail. There were other clues as well, hinting this was a wet late summer/early fall. Many service berry bushes were still loaded with fruit. The fruits were dry and wizened by then, but the fact they still clung to the brown branches suggests that berries were so plentiful this summer that the bears and birds found more than they could eat. But is this really a wet year or a normal year? What is normal? These are questions that observations of just a day or even just a season can't answer.  These are the types of questions that require gathering information long before you know you'll need it.

This monitoring station measures air temperature, 
soil moisture, relative humidity, and precipitation.
Credit: Marci Krivonen
Monitoring is not a glamorous business, routine rarely is. Yet it is consistency and long-term commitment that makes data from monitoring valuable. Monitoring is type of scientific practice whereby a single or a few variables are measured on a regular basis for an extended period of time--the longer the period of time the better. Once data on these variables has been gathered, it can be analyzed to show changes (or lack thereof) in the variables, to find natural patterns, or to compare current conditions with conditions of the past.

Human activities--where we live, what crops we grow, where we vacation--are based on assumptions about the conditions of certain areas, and if conditions in those areas change, they may no longer be able to support the our activities. Natural systems likewise require specific conditions to function and survive. By looking at conditions in the past and comparing them to the success of human or natural systems, we are able to gain understanding about what conditions are conducive to a system thriving and what conditions may threaten it.

With the widespread use of human fossil fuels that skyrocketed in  the 20th century, changes have begun occurring on our planet at a rapid rate and on a large scale. Monitoring provides a lens through which we can study those changes. Looking at a past dataset, the last 100 years of temperature for example, gives us an idea of what we may need to prepare for in the future. If we saw that the average temperatures for each year went up and down a little bit over the past century but that the cold periods and warm periods alternated pretty regularly, then we could speculate that the climate in the valley is likely to continue to be similar to conditions in the past and can plan our growing season accordingly. If the average yearly temperatures vary from year to year, but in general show that each decade is on average warmer than the last, then we can speculate that our future climate is likely to be warmer than our past one has been. Warmer temperatures on a regular basis translate into local concerns such as higher risk of fire and the possibility of drier soil during the growing season.
The famous Keeling curve shows a clear trend in atmospheric CO2. Credit: NOAA

Mundane though gathering data (by instruments or by hand) on a regular, extended basis may be, monitoring data have been the trigger for important discoveries and even political and social debate. Perhaps the most well-known example of a revolutionary monitoring application is the CO2 monitoring station on Mona Loa. Founded by Charles David Keeling in the late 1950's, the instruments on this Hawaiian volcano provided scientists with evidence that atmospheric CO2 levels were rising at an unprecedented rate. Because of CO2's role as a greenhouse gas, this data provided warning of a potential global warming trend.

Service berries cling to branches nearly bare of leaves
Service berries in November. Credit: AGCI
By giving us a window into the past, monitoring helps us to better understand what present conditions mean for our ecosystems and what we might expect from the future. So to return to the snowy November day when we hiked to our own, young monitoring station: what did the snow on the ground mean for the aspens, sage, scrub oak, and service berries that depend upon it?  It's all a matter of context. This fall (the portion that has already passed at least) received considerably more rain than the previous fall (see iRON's data page comparing 2012 and 2013). That being said, the late rains came on the heels of a dry summer preceded by a "drought condition" spring. Whether or not the trees and shrubs in this sub-alpine ecosystem survive depends on more than just a season--it depends on the cumulative conditions of a number of years. In other words, only time will tell. In the meantime, we'll be keeping tabs.