There was much to see at Grover Hot Springs a couple of weeks ago (in early May). As soon as I stepped out of the car on arriving in the campground, I found bunches of pine seedlings, most still holding on to their seed coats, scattered widely through the forest.
Why would a dozen to 30 or more pine seeds be germinating all together, as if a hand-full of seeds were planted all in one hole? Although a falling Jeffrey pine cone may hit the ground with enough force to knock loose some seeds, it’s unlikely that would explain the large number of seedlings emerging from an area of just a few square inches. It would appear that scatter-hoarding is the answer here.
Many small mammals and birds will store quantities of surplus seeds in the ground to consume later, when food supplies are scarce. It’s a common adaptation to seasonal changes in food availability. Some animals do “larder-hoarding,” where relatively few and large caches are created, then often defended. Another strategy is “scatter hoarding,” where many small hoards or even single food items are buried over a large area. Scattering the hoards provides some insurance against all of the food being lost to pilfering, but the hoarders themselves need a good memory and/or a good nose to be able to find their caches again.
Some seeds will, of course, escape both consumption by the hoarders and pilfering by other hungry critters, so they end up germinating. Producing large quantities of nutritious seeds can thus be a good way for plants to have their seeds dispersed and planted. Some plants may even manipulate the scatter-hoarding behavior of seed-dispersing animals.
Then there were galls I had not seen before, fairly common at the tips of huckleberry oak (Quercus vaccinifolia) stems. Searching the internet, I found the ones above are likely produced by Heteroecus melanoderma (Hymenoptera: Cynipidae), the Golden Gall wasp (another photo). The galls above appear to be from last year, so their golden hairs have faded or worn off.
Apparently the Heteroecus wasps are partial to canyon live oak (Quercus chrysolepis), but may also use huckleberry oak as a host plant. Aside from canyon live oak being a tree and huckleberry oak being a shrub, there are resemblances between these two oaks, and they will even hybridize.
Nearby, on the same bush, was a shorter, more squat gall (above) that appears to be that of Heteroecus sanctaeclarae, the Mushroom Gall wasp (another photo).
Cynipid wasp habitat: Huckleberry oaks beside a seasonal stream
at the edge of the pine forest.
Not galls: the acorns of Huckleberry oak.
The new checklist, Plants of Hot Springs Valley and Grover Hot Springs State Park, Alpine County, California is available for download HERE.