Monday, July 23, 2012

Pros and Cons of Local Field Work

My field sites are all within a day's drive of my home. Albeit it's a long day's drive to my sites in northern New Hampshire, but still, far easier to reach than some of my colleagues international field sites.   Three of my field sites are right here on Long Island, less than 30 minutes from my office.  I didn't necessarily pick my field sites out of convenience, but it's a nice bonus.  After college I spent two-plus years working as a Backcountry Caretaker for the Appalachian Mountain Club in the White Mountains of New Hampshire.  This experience, combined with numerous outdoor adventures throughout the northeast with my family during my childhood, instilled in me a deep love and appreciation for northeast deciduous and boreal forests.  So, when I came to grad school to study ecology, I naturally migrated to a project that I could do in this forest type.

Working close to home has many perks.  For example, generally I can look at a weather forecast and pick the nicest days to head out to my sites.  Generally I don't have to go out into the field during a down pour or a 100+ degree day.  Not that I don't spend time in the field during crappy weather, but for my Long Island sites, I can usually avoid it.  Another benefit is that I can go out to my sites just to satisfy my curiosity about field methods that pop into my head while I'm looking at my data.  "I wonder if fruit count on these plants markedly differs in July versus August versus September?" Well, I can just head out and look at my plants.

Counting fruit in July
However, there are a few cons I've experienced with having field sites so close to home.  For example, being so close to the office, I'm available to go to lab meetings, thesis defenses, random talks of interest, etc.  These events seldom take more than a few hours a piece, but it's enough to eat into my field work time.  Also, there's other projects I'm working on that feel more urgent at times - 'I can't go into the field today. I have to finish gathering data for project X!'

For me, and for many others too, being successful at grad school requires good time management.  Field work always requires time management, but having my field sites so nearby requires me to treat field visits like any other day-to-day task I have.  I often talk about my 'field season' as though it's a discreet period of time, but in reality,  it's really a portion of the year during which I shuffle in a few more tasks into my daily life.

Update: Since I wrote this short post, another researcher has also written a great piece on doing local field work. I figured I'd link to it here:

Thursday, July 12, 2012

On how I chose my samples - Part 1

One of the early challenges I had in doing field work was deciding how to chose plants to measure and tag for long-term monitoring.  At this point, I have read quite a bit about this topic and always take notice of descriptions of this process when they appear in papers. Sadly, such descriptions generally consist of a sentence or two buried somewhere between 'Study Species' and 'Study Site'. I did not have any formal field ecology experience prior to starting graduate school and my research adviser doesn't have any field based projects, so I felt a bit on my own in coming up with a sampling scheme. That's not to say that I didn't get advice from some very smart and experienced folks - just that at the end of the day, I had to cobble together a sampling scheme based on lots of reading, a fair bit of discussion, and a very small amount of experience.

My small bit of experience came by way of working as a Graduate Assistant to the chair of the department here at Stony Brook, Dr. Jessica Gurevtich. Dr. Gurevitch and her colleagues have been monitoring the post-fire recruitment and demography of pitch pine (Pinus rigida) here on Long Island since 1996.  The fire that affected these field sites was in 1995, and growing up near by, I remember it fairly well. Some of the results of this research have been published (Landis et al. 2005; Fang et al. 2006). As Dr. Gurevitch's GA, part of my job was to help out with the Pine Census during the summer of 2009, which that year was organized by my friends Adam and James.  In total, over the years well of 6000 pitch pine trees have been tagged with either plastic bird-band tags or aluminum tags, and once every two years a group of people would go out into the Long Island Pine Barrens, search for these marked plants, and take measurements - such as diameter at ankle height, diameter at breast height (DBH), height, presence/number of cones, etc.  When the census was initially established, 45 square 5x5m plots were distributed across various tree stands within three landscapes.  All pitch pine plants, and those that emerged during the study period, within these 45 plots have been tagged and measured.  It's a lot of work and a lot of data! So when I set to designe my sampling scheme, I had some notion that it would involve square plots and marking all of the Glossy Buckthorn plants inside of those plots with aluminum tags.  

Ok - plots and tags - that made sense.  However, the few papers actually related to Glossy Buckthorn that I had found (nearly all from groups at UNH associated with either Drs. Tom Lee or Robert Eckert) had used transects.  And transects seemed so much easier! Lay down a measuring line, then walk along it.  So, near the end of the summer of 2009, I head up north to the White Mountain National Forest (WMNF), walked into a field of Glossy Buckthorn and laid down a transect.
One end of a transect in WMNF
And this is when I learned that transects are not always the best option.  For one, I wanted to place the transect down in a random spot, and what that meant was that my tape was laid down right next, but not touching, a large patch of buckthorn.  Moving my tape would be biasing my data collection, but not having my tape touching any buckthorn made that transect useless.  Then, I couldn't help but notice that some of my transects went through incredibly dense stands of buckthorn, with trees that had pretty low fruit count, while other transects went through very sparse stands of buckthorn, but each tree had hundreds, if not thousands of fruit.  Hmm ... and this lead to a realization I should've had much earlier - before you decide on a sampling scheme, you have to know what you're planning on doing with the data you collect.  And I don't mean have some vague notion like, 'I'm going to make a demographic model!', I mean, you need to know what values you need to estimate, how much error is acceptable, how you're planning on dealing with outliers and missing data, and there's a whole slew of other things to think about carefully.  So I headed back to Stony Brook and gave this a lot more thought.  And that I'll talk about in the next post.

Landis et al. 2005. Variation in recruitment and early demography in Pinus rigida following crown fire in the pine barrens of Long Island, New York. Journal of Ecology 93(3):607-617.

Fang et al. 2006. Sources of variation in growth, form, and survival in dwarf and normal-stature pitch pines (Pinus rigida, Pinaceae) in long-term transplant experiments. American Journal of Botany 93(8):1125-1133.

Wednesday, July 4, 2012

Another Field Season Begins

While carrying out my field work in the past I've often thought, "Hey, it would be nice to document some of the thoughts that pop into my head while standing out here measuring plants." Most of these thoughts have been related to the process of trying to figure out how exactly to go about doing my field work. Perhaps they may blossom into something useful to me, or perhaps someone else might find them interesting. Regardless, I should write them down. And so, I thought I could use some motivation to write and the world probably has room for another blog. I have every intention of writing about ideas that are not born from my field work too, but this seems like a good place to start.  Here's a picture of how happy I look when standing in a thick patch of Glossy Buckthorn (F. alnus), a non-native plant I'm studying as part of my Ph.D. dissertation work. I'll discuss it more later, but I also have a blurb about my research here.
For now, let me explain this blog's logo, the image to the right that reads 'Ecologist at Work'.  As an ecologist, I'm working towards being many things: a conservation biologist, a quantitative ecologist, a plant ecologist.  It is in working towards the latter that I get to do my field work.  My field sites are generally pretty close to hiking trails.  There are a few reasons for this that I can think of: 1) non-native plants generally grow closer to places that are disturbed, such as roads and trails; 2) many of my sites are in fairly developed areas (e.g. Long Island, NY and southern New Hampshire), thus every plot of woods is either near a trail or a road or someones backyard; and 3) ok, I admit it, access to sites near trails is much easier.  However, even though I'm am near trails, my plots are still off into the woods a bit.  So, while someone is out enjoying a walk in the woods or a jog through the park, they may stumble upon a scene in which a relatively dirty looking man is thrashing around the bushes, just off the trail, with a long stick (a measuring pole) or a saw (to take samples).  Or perhaps they may see a man quietly crouched behing a tree (measuring the basal diameter of a plant).  In any case, the hiker usually appears pretty sketched out.  Last season I had the thought that I needed a folding sign that said 'Ecologist At Work' to put out in the middle of the trail, something to let hikers know that there may be someone just off in the woods cursing about falling into a black berry bush, again.  Mostly this thought was in jest, but during my first field day this year, I looked up from my measurements just in time to see a young jogger come around a corner, see me, and promptly turn and run back the way she had come.  I thought, "I really need that sign".  So I enlisted the help of my awesomely talented sister-in-law, Andrea Sorrentino, and she put together this awesome designe.  Next step, get it printed out on a folding construction sign! So if you see such a sign in the woods, just say hi to the ecologist off in the woods.