June 3rd, 2008

woods, Elizabeth, camera, April

80 acres: Diversity

New (newly noticed/IDed) species go on the list as soon as I've seen them (and usually after being photographed for documentation and ID, though some critters aren't very cooperative about that.)

Periodically--several times a year--I spend the time to count up the increase, taxon by taxon.  Yesterday, since I had a nasty headache, seemed a good day for that chore, so I printed out the current list (could not face the glaring computer screen that long) and went to work.  Here are the results:

Total species identified on the entire place: 778
Total plant species: 318
Total animal species: 460

The critters are not confined to the place, of course, and many are seasonal (transients using it in fall or spring, summer-only residents in summer, winter-only residents in winter.)   Others are permanent residents in the area but with a much larger range than our land provides, so they are on it only part-time.  Doesn't matter to me.  What does matter is the dramatic increase in native plant species in 7 1/2 years and the increase in specific groups of critters (the ones we counted right at the start) responding to the improvement in resources.  I know there's a lot that hasn't been counted (not that many plants, but certainly among the invertebrates) so the count should continue to rise.

Current numbers for a few taxa: 

Trees and woody shrubs: 56 species
Grasses: 50
Forbs: 144
Mammals: 20
Birds: 151
Butterflies & moths: 77
Dragonflies & damselflies: 48
Beetles: 21

Population sizes range from fewer than ten (Scheele's setaria, a grass found in only one location with only a few individuals) to "more than I can count" (Lone Star tick, not my favorite critter., and many other abundant invertebrates.)   It would be great to hit 800 species by the end of the year (the end of our 8th year of management) but that's just human-thinking, making the numbers neat.  More species, more diversity, especially the more natives, indicates a healthy balance, an enhanced food web and more complex cycling of nutrients.  All good stuff you want. 

If the 80 acre field we now own had sold to a developer in 2001, and become, say, a shopping center, the species count would be WAY down.   Oxygen production would have dropped to zero.  Carbon emissions would have risen.   No rainwater would infiltrate roofs and pavement to replenish the aquifer;  and  290,545 cubic feet of dirty runoff would flood the creek with per inch of rain.  (80 acres/12 inches/foot = 6 2/3 acre-feet of water per inch of rainfall.  An acre-foot is 43,560 cubic feet. )   Instead, it's home to over 770 species of plants and animals, absorbs many rains with  no runoff, and its ~20 acres of woody vegetation sequester the carbon from an average car driving more than 500,000  miles.  (That figure comes from research showing that 1 acre of central Texas "thicket"  takes in the carbon from 26,000 miles of driving.) 

Yeah, I'm kinda bragging here.  But not a lot, because there's a lot still to do with this 80 acres, and I would love to get hold of the acreage between it and the county road to the north--another run-down piece of ag land.  There's a T-intersection, the kind of place developers long to find so they can pave it over.