We hiked today for a few miles through Soldiers Delight Natural Area in Western Baltimore County to listen to and explore the varied habitats of a serpentine barrens. The underlying bedrock and thin soils are full of heavy metals, mineral poor, and inhospitable for most plants. The words toxic, poisonous, and rare seemed to pique my teenage grandkid's interest as I described this protected landscape.
|Serpentine bedrock and thin soils below the grasslands.|
The stark differences between the plant communities on serpentine soils and what was growing down slope in richer soils was dramatic. The difference between the two sites comes down to Calcium. A micro-nutrient essential for plant growth, the absence of Calcium is a limiting factor for what can and can't grow in serpentine areas. On serpentine bedrock and its weathered, thin soils, Calcium is absent while Magnesium is very high. It's a toxic environment where grasses and some very tough trees dominate.
We encountered a Common Wood Nymph butterfly on its last legs, flopping and weak, struggling across the trail. I moved it carefully to the side and watched as it struggled to climb a blade of Purple Top Grass in a sea of Little Blue Stem, an iconic species of the Eastern Prairie. We looked hard for some of the rare butterflies as well but struck out this time.
As we walked, I was thinking about all the different kinds of prairie that I've visited. I love them all. Grasslands are some of my favorite places to be, especially the rolling Blue Hills of Kansas and the gravel prairies of glaciated Illinois and Wisconsin. The oak-savanna of Iowa and the Appalachian balds are some of my favorite butterfly spots. I remembered the Scrub Oak leaf that a grad school friend brought me from the high chaparral of California and wondered where I'd put it. I found it later pressed in my Peterson's Trees of the Western U.S. still smelling of sagebrush. I found a fallen Post Oak leaf to compare it to at home.
|Little Bluestem, iconic native Eastern Shortgrass species. |
|Purple False Foxglove|
Calcium is essential to plant growth and is absorbed by roots and carried upwards through the xylem to where it is used to build cell walls, especially at the growing tips. But it cannot be stored by the plant - it must be readily available when needed in the soils where the plant grows. Serpentine is a terrible "keeper" of Calcium and challenges plants with a superabundance of heavy metals. Kenz is just beginning sophomore year in high school and takes her first biology course this semester, so a discussion of micro-nutrients and cell growth seemed the perfect topic to mention as we walked. Hiking through Calcium deficient fields of prairie grass made a great see-for-yourself experience of adaptive and tolerant plant communities.
We looped around through Greenbriar thickets and mixed oak-pine mixed deciduous woods and made note of how trees contributed leaf litter and decaying wood to building a soil base. Here we found a variety of fall fungi and made quick forays into the woods to snap pictures of those that caught our eye. Are there fungi in the grasslands? we wondered. Are mycorrhizal networks present in serpentine soils and if so, how do plant communities utilize them? Ah, ecology, I said to Kenz, who gave me the famous teenager's shrug.
|Wrinkled Psathyrella, Psathyrella piluliformis|
|Turkey Tail, Trametes versicolor|
|This mushroom's collar has just fallen away.|
|Red-mouth Bolete - Poisonous beauty|