Ecology Underfoot

    When you think of ecology, you probably think large and grand - towering rainforests, the depths of the ocean, acres of rolling grasslands. But ecology can also occur on very small scales, and closer by than you think!

    Across the street from Harvey Mudd college is the Robert J. Bernard Field Station, an 86 acre portion of native Californian ecosystem preserved for scientific study. As part of the class Experimental Ecology Laboratory, I go every week to take ecological observations of the native plants and animals there in my field journal. In past weeks, I have taken notes on a particularly fascinating cluster of cacti, the birdcalls I heard in the distance, and an oak tree overgrown with Wild Cucumber vines (Marah macrocarpa). This last week however, I zeroed in on something significantly more humble - the ground between the California sagebrush (Artemisia Californica) bushes that dominate the coastal sagescrub ecosystem present in the southern portion of the field station. I plopped my field journal on the ground, sat next to it, and started taking notes on everything I saw in the patch of bare ground next to me.

The area of ground I observed, with my journal and pencil for scale [1] 

    Of course, bare is a misnomer. What looks at first glance like a boring patch of sandy earth is in fact covered in tiny but fascinating organisms. The first thing that stood out were the tiny bright yellow flowers you can just barely see on the upper right edge of the above image. To aid in identifying these, I used the community science app iNaturalist, whose AI camera identified these flowers as California suncups (Camissoniopsis bistorta). Having identified them, I observed that the many other patches of radially spread leaves visible in the dirt had the same shape and structure of the leaves of the suncups just without the flowers, implying that they were also suncup plants. This patch of dirt might have more flowers at some point in the future!

A California suncup flower with my hand for scale [2]  

A cluster of suncup plants lacking flowers [3]

    I also identified a few small patches of what iNaturalist identified as bonfire moss (Funaria hygrometrica). I am however suspicious of this identification, because bonfire moss is supposed to grow in wet and shady environments, which does not match the sandy and sundried soil of this area. It’s possible that I saw it because it rained last week - some of the more shaded patches of soil still held some of the moisture - but it’s also possible that this is a misidentification; mosses are very hard to identify and I could not find any list of the mosses known to be present at the field station.

A patch of what may or may not be bonfire moss [4] 

    These were far from the only organisms in this seemingly bare land. In fact, the earth was covered in small grasses! There were many patches of very short (1-2cm) grass that grew in a tufted manner, with many thin blades of grass emerging from what seemed to be the same root, with the tufts separated by one or two centimeters. There also were a few areas that had what seemed to be a different species entirely - much longer stems (maybe 5 - 6cm?) which had only one or two blades of grass extending from them which branched off above the ground. Unfortunately, iNaturalist proved unable to identify these species, and although there are ways to identify grasses manually, these ones were simply too small for me to make out the features that would allow for identification.

Snapshot of my field notes about these two species of grasses, including sketches [5]

    The difficulty of identifying such tiny plants was a problem throughout the process of this observation. When making field observations, I tend to rely heavily on iNaturalist’s AI camera to identify plants, since my personal plant identification knowledge is somewhat lacking. But it turns out that Naturalist’s prowess was sorely tested by small and rather generic looking plants like many of these ground grasses and mosses. For many of the small plants I tried to identify, all iNaturalist could tell me was that they were dicots - an extremely broad classification which covers almost 200,000 species ranging from tiny herbs to trees! And for those grasses above, iNaturalist did even worse, giving me the incredibly unhelpful information that the organism I was attempting to identify belonged to the kingdom Plantae - that is, that it was a plant. Thanks iNaturalist! I also used the Bernard Field Station list of native plants to use confirm some iNaturalist identifications I was unsure about, such as the sand pigmyweed (Crassula connata) which looks very similar to another native plant, leather spineflowers (Lastarriaea coriacea). The two plants look quite similar; spineflowers have red stems and green leaves while the sand pigmyweed has green rounded leaves surrounding tiny red flowers. However even with this list I couldn’t identify many of the small plants present in this ecosystem, and I was forced to give up because my eyes were hurting from trying to focus on plants where the entire organism was smaller than my fingertip. Small scale ecology is hard!

 

Images of several of the small plants I was unable to identify [6] 

    I think the most notable part of this whole observation was that all of the plants I have described above were observed in a very small area - less than a square meter. From standing position looking down I could hardly see anything, let alone anything interesting - but once I crouched down and zoomed in there were dozens of unique plants, many of which were beautiful. I’ve probably stepped on these plants every time I’ve been to the field station before, and never would have known they were there if I hadn’t thought to look deeper. What this teaches me is looking is not the same as observing, and there are objects of ecological interest in places that I have seen many times without ever actually noticing. I wonder what unexpected location will be the subject of my next investigation!

Media Credits:

[1]: Photo by Anna Figge

[2]: Photo by Anna Figge

[3]: Photo by Anna Figge

[4]: Photo by Anna Figge

[5]: Photo by Anna Figge of own lab notebook

[6]: Photos by Anna Figge