Wednesday, May 27, 2015

Rock Point inventory: Brick's Brook

Next stop: Brick's Brook. Much of the sediment deposited atop the calcareous bedrock is lacustrine in origin (from a lake), deposited 11,000 years ago when the glaciers were retreating - melting - but still blocking drainage of the fresh water to the north through the St Lawrence seaway. Water pooled up in the Champlain Valley, the only outlet being the Hudson River valley to the south. The drainage point here is about 600', so Lake Champlain, which was known as Glacial Lake Vermont, was about 500' above where it is today.
The wet meadow, this is the "headwaters" of Brick's Brook

At the edge of the meadow, it starts to cut into the soils
About 25 down from previous photo, excessive erosion exposing roots of white pine
(which once upon a time was a fence line as witnessed by the barbed wire embedded in it)
The melt water draining off the mountains into the lake via the Winooski, Mississquoi, Lamoille, etc. would have been a muddy mess with glacial sediments. So Rock Point, which is adjacent to the lake, would have been a deep water environment, buried in alternating layers of silts and clays each year when the lake froze over. These silts and clays drain very poorly, accounting for  the wet meadows and depressions found scattered over the land.

Further still downstream. Slopes of banks still steep. 
Once the glaciers retreated far enough to the north, finally opening up the St Lawrence seaway, water exploded out of the Champlain Valley, draining in a matter of hours or days down to an elevation of 300'. At that point, because the glaciers were so heavy, their weight had actually depressed the entire northern part of the continent - much like a large putting all your passengers at the stern of a flexible boat - by about 300' in this area. The glacial lake gradually grew saltier and saltier as water from the ocean filtered into Champlain Valley. The rivers continued flowing into the body of water; the Winooski River delta's edge terminated at Rock Point, depositing patchy layers of sand atop the lacustrine silts and clays.

Soil map generated by Web Soil Survey:
This sandier stuff erodes rather easily. Brick's Brook, which is only about 600m in length, starts as a trickle in the Old Pasture. A small bridge passes over the small notch carved into the clay soils. At the edge of the meadow, soils are much sandier and within 50m, the notch is a deep valley with steep slopes. Eventually the stream eroded down below the sandier soils, exposing silts and clays. Because these smaller soil particles are more difficult to erode, the valley widens rather than cutting further down. Towards the lower end of the stream the slope of stream is much gentler, water does not drain as well, and the course of the stream begins to meander, with water pooling up much more. In this section there are often green frogs and wood frogs.

Near the bottom, mellow grade to the brook and shallow slope to the banks due to erosion over time
High water table wreaking havoc on the hemlcoks and yellow birches
Species list is not complete (there are 5 different plants I need flowers to key out):

Maple, redAcer rubrumAceraceae (Maple)
Maple, sugarAcer saccharumAceraceae (Maple)
Ivy, poisonToxicodendron radicansAnacardiaceae (Cashew)
Birch, yellowBetula allegheniensisBetulaceae (Birch)
Viburnum, maple-leafViburnum acerifoliumCaprifoliaceae (Honeysuckle)
Honeysuckle, ??Lonicera ??*Caprifoliaceae (Honeysuckle)
Bittersweet, orientalCelastrus ????*Celastraceae (Bittersweet)
Dogwood, red-osierCornus sericeaCornaceae (Dogwood)
Witch-hazel, AmericanHamamelis virginianaHamamelidaceae (Witch-hazel)
Basswood, AmericanTilia americanaMalvaceae (Mallow)
Ash, greenFraxinus pennsylvanicaOleaceae (Olive)
Hemlock, EasternTsuga canadensisPinaceae (Pine)
Buckthorn, commonRhamnus cathartica*Rhamnaceae (Buckthorn)
Buckthorn, glossyFrangula alnifolia*Rhamnaceae (Buckthorn)
Blackberry, commonRubus allegheniensisRosaceae (Rose)
Cherry, blackPrunus serotinaRosaceae (Rose)
Raspberry, blackRubus occidentalisRosaceae (Rose)
Rose, multi-floraRosa multiflora*Rosaceae (Rose)
ThimbleberryRubus odoratusRosaceae (Rose)
Aspen, quakingPopulus tremuloidesSalicaceae (Willow)
GRAPE sp.Vitaceae (Grape)
Virginia creeperParthenocissus quinquefoliaVitaceae (Grape)
Jack-in-the-pulpitArisaema sp.Araceae (Arum)
Jewelweed, spottedImpatiens capensisBalsaminaceae (Touch-me-not)
Solomon's seal, falseSmilacina racemosaLiliaceae (Lily)
Crowfoot, small flowerRanunculus abortivusRanunculaceae (Buttercup)
Lily, troutErythronium americanumLiliaceae (Lily)
Skunk cabbageSymplocarpus foetidusAraceae (Arum)
DandelionTaraxacum officinalis*Asteraceae (Aster)
Meadow rue, earlyThalictrum dioicumRanunculaceae (Buttercup)
Baneberry, redActaea rubraRanunculaceae (Buttercup)
Nightshade, enchantersCircaea spOnagraceae (Evening primrose)
MiterwortMitella diphyllaSaxifragaceae (Saxifrage)
Nettle, woodLaportea canadensisUrticaceae (Nettles)
Nightshade, deadlySolanum dulcamara*Solanaceae
SpeedwellVeronica spScrophulariaceae (Figwort)
Fern, ladyAthyrium filix-feminaAthyriaceae
Fern, brackenPteridium aquilinumDennstaedtiaceae (Bracken)
Wood fern, spinuloseDryopteris carthusianaDryopteridaceae (Wood fern)
Wood fern, intermediateDryopteris intermediaDryopteridaceae (Wood fern)
Horsetail, woodEquisetum sylvaticumEquisetaceae (Horsetail)
Horsetail, meadowEquisetum pratenseEquisetaceae (Horsetail)
Fern, sensitiveOnoclea sensibilisOnocleaceae (Sensitive Fern)
Fern, ostrichMatteuccia struthiopterisOnocleaceae (Sensitive Fern)
Fern, cinnamonOsmunda cinnamomeaOsmundaceae (Royal fern)
Fern, interruptedOsmunda interruptaOsmundaceae (Royal fern)
Fern, maiden hairAdiantum pedatumPteridaceae (Maidenhair)
Fern, New YorkThelypteris noveboracensisThelypteridaceae (Marsh)

Monday, May 25, 2015

Rock Point Inventory - Hem of the Woods

Stand of hemlock, patches of moss indicating exposed bedrock (Dunham dolomite)
So it begins, my documenting of the plants of Rock Point, that is. Realizing I'd miss the early spring ephemerals, I thought I'd just start with the patches with lowest diversity and the ones that I'm most familiar with, before covering the rest of the property. I hope to finish these other patches by next summer. I spent a couple of hours this morning wandering around in my first area, which we call Hem of the Woods SW. Hem of the Woods is almost entirely hemlock in the overstory with very sparse cover in the understory. It is bordered to the NE by an artifical slope excavated out for the Island Line - now the bike path, the lake to the W, and a mature sugarbush along its southern border. Much of the diversity of plant life here is found at the borders or in breaks in the canopy.

Stand of wild sarsaparilla in foreground, growing in shade of a couple recently
downed hemlocks (one massive). Birch is relic of older logging
In one such sunny spot at the intersection of two trails where a few trees were cleared out (stumps remain as evidence), flowering plants thrive. In Hemlock Forests (yes capital H and F, see Wetland Woodland Wildland for the reference), flowering plants are incredibly uncommon. The anomalously high number of flowering plants in the understory can be attributed to the small size of the patch. In most cases, the understory vegetation is represented by small clumps of a single species, most of which can spread rhizomatically (e.g. posion ivy, rock polypody, false Solomon's seal, Canada mayflower). The seedlings are represented by an abundance of black cherry, a single basswood, occasional sugar maples, and several Norway maples, surprisingly. Shrubs were not abundant, and include glossy buckthorn, honeysuckle and red elderberry.

Doll's eyes flower stalk
The two main limiting factor at this site are sunlight and shallow soils on calcareous bedrock. Lack of sunlight is controlled by the existing canopy in addition to a northern aspect. Where the deltaic sandy soils from the Champlain Sea era have eroded away with the occasionally flooding of the intermittent stream, Brick's Brook, the canopy is still composed of hemlock.

Red baneberry growing adjacent to doll's eyes. Note the much thinner stalks that the flowers grow from
Below is a complete list of all the vascular plants I saw, except for the ferns (* = non-native).

Trees + Shrubs
Hemlock, EasternTsuga canadensisPinaceae (Pine)
Maple, sugarAcer saccharumAceraceae (Maple)
Birch, whiteBetula papyriferaBetulaceae (Birch)
Basswood, AmericanTilia americanaMalvaceae (Mallow)
HophornbeamOstrya virginianaBetulaceae (Birch)
Buckthorn, commonRhamnus cathartica*Rhamnaceae (Buckthorn)
ThimbleberryRubus odoratusRosaceae (Rose)
Cherry, blackPrunus serotinaRosaceae (Rose)
Maple, NorwayAcer platanoides*Aceraceae (Maple)
Dogwood, alternate-leafCornus alternifoliaCornaceae (Dogwood)
Ivy, poisonToxicodendron radicansAnacardiaceae (Cashew)

Mayflower, CanadaMaianthemum canadenseLiliaceae (Lily)
Hepatica, round-leafHepatica americanaRanunculaceae (Buttercup)
Jack-in-the-pulpitArisaema sp.Araceae (Arum)
Wild sarsaparillaAralia nudicalisAraliaceae (Ginseng)
Jewelweed, spottedImpatiens capensisBalsaminaceae (Touch-me-not)
Solomon's seal, falseSmilacina racemosaLiliaceae (Lily)
Twisted stalkStreptopus lanceolatusLiliaceae (Lily)
Stinking BenjaminTrillium erectumLiliaceae (Lily)
Trillium, large-floweredTrillium grandiflorumLiliaceae (Lily)
Bellwort, sessile-leavedUvularia sessilifoliaLiliaceae (Lily)
Bellwort, large floweredUvularia grandifloraLiliaceae (Lily)
Crowfoot, small flowerRanunculus abortivusRanunculaceae (Buttercup)
Violet, downy yellowViola pubescensViolaceae (Violet)
SpikenardAralia racemosaAraliaceae (Ginseng)
Mystery mintLamiaceae (Mint)
Fern, christmasPolystichum acrostichoidesDryopteridaceae (Wood fern)
Oak-fernGymnocarpium dryopterisDryopteridaceae (Wood fern)
Wood fern, intermediateDryopteris intermediaDryopteridaceae (Wood fern)
Fern, sensitiveOnoclea sensibilisOnocleaceae (Sensitive Fern)
Polypody, rockPolypodium virginianumPolypodiaceae (Polypody)

Tuesday, May 19, 2015

Rock Point species inventory

Gill-over-the-ground, Ground Ivy, Creeping Charlie, super common lawn plant
So my amphibian project didn't work out as well as I had hoped, at least in a formal way due to travel and end of semester madness. I did, however, get out to visit a bunch of new breeding spots. Now that it's green in the forest and I have a bit more time on my hands I've decided to return to a project I started a number of years ago, documenting all (well most of) the plants at Rock Point. I'll focus first on wildflowers and as spring progresses, fill in the blanks on ferns, then shrubs and trees in the fall and winter. Photographs are of "type specimens" the first that I observed. Notably absent will be the grasses, mosses, and other of the more esoteric taxonomic groups.

Wild columbine (on calcium rich outcroppings)
Fringed polygala, not very abundant, but supposedly common across its range
Large-flowered trillium, prefers oak/maple and younger forests
Over the next few months I'll highlight many of these species in posts here. For each species, I'll track which patches of land at Rock Point they're found in using the map. It isn't completely finished yet, but will be in the next few weeks as I wanted to get a more accurate delineation on some of the forest types before finalizing. I'll be keeping a spreadsheet of all the plants and where each can be found for cross-referencing, which I'll post later.