So, in the post below, and probably in a number of posts that will follow, I criticize the results of or approaches to research that relies on field botany and plant identification. I should say now: it’s hard. None of us always get it right and mistakes will be made. A major target of my ire tends not to be that people aren’t perfect botanists, but that I think there is a systematic undervaluation of botanical expertise. Field personnel whose work requires them to be able to identify plants are often poorly trained and poorly paid, because the difficulty of the work is not appreciated. So far as I can tell, land management agencies and ecological research stations assume that someone who’s taken a couple of courses in plant taxonomy can be sent into the field and will bring back reliable data. Well, I’ve taken those courses, I’ve taught those courses, I’ve botanized extensively across much of the western United States, and I can tell you (assuming, hypothetically, a reader) now: this simply is not the case.
Someone who’s taken the courses available at NMSU (Rangeland Plants, Rangeland Grasses, Plant Taxonomy), done well and studied conscientiously, should be able to sight-ID a fair number of the common species (but few of those uncommon species that make up most of the biodiversity), and should be able to key out most plants assuming there is flowering and/or fruiting material available (and there often isn’t, but field crews don’t tend to have the luxury of waiting for good conditions). But that’s it. Don’t expect or rely on sight-IDs of most of the plants in the area, and don’t expect that any kind of identification will be possible for most species if the plants are in poor shape and many or most of the diagnostic characters are absent.
Suppose you want to answer a simple question: is plant diversity higher in grasslands or shrublands in southern New Mexico? Well, if you want reliable data, you need a field crew of people who already have several years of experience–probably voluntary / recreational since, AFAICT, no one will pay you to learn plants–botanizing in the area. Those people are scarce, and most of them have Masters or PhD degrees (and many are retired!); you probably can’t (and, ethically, shouldn’t) hire them for crappy minimum or near-minimum wage temporary positions. If, on the other hand, you hire a field crew of people fresh from their undergrad degrees whose experience is limited to two or three courses in plant ID or taxonomy, either that crew is going to be spending 90% of its time learning plant ID, or you’re going to get crappy, unreliable data. (As for the simple question, so far as I know there is no reliable answer! More on that some time later.)
One way to minimize the expertise required is to only focus on a few of the dominant plant species (as in the vegetation maps discussed in the post below). It is better to recognize one’s limitations and work within them, but this approach means you’re ignoring most of the botanical diversity in the area… not exactly ideal, in my opinion.
The gist is, if you try to fill botanical field crews on the cheap, rather than hiring highly trained botanists with extensive experience, you have a few options, none of them particularly good: deal with poor accuracy of identifications; get very little data back because your field crews are spending most of their time learning the plants; adopt a very myopic view of plant communities.