Posts Tagged ‘alkali soils’

The Curious Disjunct Range of the Miccosukee Gooseberry (Ribes echineiium)

April 25, 2012

The Miccosukee Gooseberry grows in just 2 counties hundreds of miles apart.  One population clings to the shoreline of Lake Miccosukee in northwest Florida, and it numbers about 5,000 individuals.  The other population lives in McCormick County, South Carolina near the eastern border of central Georgia 1.5 miles north of Clark Hill Lake.  In this county there are 2 separate populations: 1 group is in Sumter National Forest and the other is located in the Steven’s Creek Heritage Area.  The McCormick County population is estimated to number between 13,000-160,000 bushes.

Leaves, flowers, and twigs of the rare Miccosukee Gooseberry.  I couldn’t find a photo of a whole bush on the web.

I suspect the Miccosukee gooseberry had a wider, more continuous range during the Pleistocene and maybe as recently as the Colonial era.  I hypothesize its decline to relict status is probably tied to the extinctions of the mastodon and the passenger pigeon.  Several clues support my hypothesis.  Notice the remaining populations grow near water.  They grow near the shore of Miccosukee Lake in Florida, and on a steep north-facing slope along Steven’s Creek.  Mastodons were semi-aquatic, and passenger pigeon flocks roosted along water ways.  The surviving colonies are likely remnants of once larger colonies that thrived thanks to the bio-activities of mastodons and passenger pigeons.  Mastodons facilitated the growth of gooseberries by eating branches and leaves of overstory trees, thus allowing more sunlight to reach the low growing bushes which don’t exceed 3 feet in height.  Mastodons helped spread gooseberries by eating the bushes–the pruning caused the plants to spread vegetatively–and by spreading the fruit seeds in their dung.  Passenger pigeon flocks had the same effect.  When the incredibly enormous flocks of passenger pigeons roosted in one area, their dung would cover the ground, killing the trees through overfertilization, and opening the canopy to the benefit of plants such as gooseberry which became one of the first floral species to colonize a pigeon roosting area after the tree kill (pokeberry and ginseng are 2 other plants noted for growing in this type of environment).  Poultry manure also raises the ph level of the soil.  The Miccosukee gooseberry only grows on alkali “sinks.”  The pigeons were also known for berry consumption and were capable of spreading the seed far and wide due to their highly migratory habits (their scientific name is Ectopistes migratorius).

Miccosukee gooseberries have a low germination rate, probably contributing to their relict geographic range.  This species may have been more widespread during the Pleistocene when mastodons roamed the land.  Mastodons helped propagate this species in several ways.  Mastodons ate tree branches, thus allowing more light to reach the low growing gooseberries.  When mastodons ate the gooseberry bushes, it facilitated the growth of clonal colonies which spread via the root system.  The gooseberries may have had a higher germination rate after passing through a mastodon’s digestive tract.

Miccosukee Gooseberries may have also relied on passenger pigeons to spread their seed.  Passenger pigeons carrying gooseberry seed in their gut could spead the species far and wide.  It’s probably no coincidence that the last 2 populations of Miccosukee gooseberries are located in the kind of habitat where massive flocks of pigeons formerly roosted.  The manure from the massive flocks of roosting pigeons raised the ph level of the soil.  This type of gooseberry only grows on soils with a high ph.

Scientists attempting to ensure the survival of this species of gooseberry face some obstacles.  The Miccosukee gooseberry has a low germination rate.  This low germination rate supports my hypothesis that its decline coincides with the extinctions mentioned above.  It’s likely gooseberry seeds need to go through the digestive tract of a mastodon or pigeon to improve germination.  Efforts to transplant and propagate the Miccosukee gooseberry have been a complete failure.  This species has low genetic diversity, but there is a high degree of genetic divergence between the Florida and South Carolina populations, evidence they’ve been isolated from each other for quite some time.  The species wasn’t known to science until 1924, a generation after the extinction of the passenger pigeon.  There’s no telling what its range was during the 19th century.  The South Carolina colony wasn’t discovered until 1957.

The Steven’s Creek population grows under a canopy of oaks, hickories, and beech.  Gooseberries leaf out in November and lose their leaves in mid-summer, thereby taking advantage of the increased sunlight they experience when deciduous trees drop their leaves.  Bumblebees and blueberry bees pollinate the flowers.  One source claims the fruit is delectable but sour; another source says the fruit is of poor quality.  I suspect the latter source is closer to the truth, but I don’t know because I’ve never eaten this variety.

Unlike the Miccosukee gooseberry, the eastern prickly gooseberry is more widespread ranging from the midwest to the southern Appalachians.  Reportedly, they are fairly common on Grassy Mountain in the Cohutta Wilderness Area of north Georgia where they grow on boulderfields in the understory of a birch-maple forest.

The eastern prickly gooseberry (Ribes cynosbati) is common throughout the midwest and as far south as the southern Appalachians.  Reportedly, they are a frequent component of an interesting forest growing on Grassy Mountain within the remote Cohutta Wilderness Area of the Chattahoochee National Forest.  According to Jennifer Moore who wrote her college thesis about the forest on this mountain, the prickly gooseberry grows among the boulderfields on Grassy Mountain.  The name is a misnomer–it hasn’t been grassy for over 100 years since pastoralists abandoned the land, and trees began growing in the absence of livestock grazing and fire.  The boulders are the result of severe Pleistocene freeze and thaw cycles that broke up the rocky mountain surface.  A forest of mountain maple, yellow birch, tulip tree, basswood, and buckeye dominates over a shrub layer consisting of smooth hydrangea, strawberry bush, raspberry, prickly gooseberry, and marginal wood fern.  Windthrows are common here, aiding the growth of the shrubby zone.  Much of the mountain is inaccessible to non-hikers, making it a real destination for people seeking solitude with nature.  Better bring pepper spray–I bet there are lots of bears here.

I’ve never eaten a fresh gooseberry.  They aren’t cultivated in Georgia as far as I know.  I tried growing some a long time ago but the plants croaked in the merciless heat.  The canned ones taste like sweetened okra.  Even canned gooseberries are rare in Augusta–none of the local grocery stores currently carry them.

Here’s a related article on Pleistocene Passenger Pigeon Populations. https://markgelbart.wordpress.com/2010/08/27/pleistocene-passenger-pigeon-populations/