Saturday, April 28, 2012

More little leaves

American beechRed oak

Witch-hazel with veery

Striped mapleStriped maple

Silver maple
What: So in response to Ryan's comment about sugar maples being considerably later than their breathren to leaf out I set out to document some of the later-to-burst buds. A loose pattern I thought I found was that the later species to bud out seem to be the ones that are more shade tolerant. But my sample is too small to make anything other than a very gross generalization (and probably not that correct). I also didn't notice whether or not there's a difference between individuals in the canopy and individuals in the understory. I couldn't find great data on the order of when species leaf out (Project Bud Bursts data set isn't that great) so looks like I'll have to keep investigating.

I know that there is variation within a population due to small-scale climatic features. In the posting on dandelions I described finding dandelions that had gone to seed earliest in south-facing spots adjacent to buildings or rocks. Trees in similar warm areas tend to leaf out earlier. I followed up on the shade-tolerance piece and didn't find a whole lot pertinent to leafing out. It is pretty well established that a woody species' shade tolerance is most relevant in the seedling/sapling stages. The following table is condensed from Humbert et al.'s 2007 paper "A shade tolerance index for common understory species of northeastern North America". It gives ranks each species from 1-9, with 9 being the least tolerant of shade and 1 being the best, an X means that it has a wide range of tolerances. The real table has more trees, lots of herbaceous plants and even some mosses and liverworts.

Latin name
Common name
Shade tolerance index
Abies balsamea
Balsam fir
3
Acer pensylvanicum
Striped maple
3
Acer rubrum
Red maple
5
Acer saccharum
Sugar maple
4
Acer spicatum
Mtn maple
5
Alnus incana ssp. rugosa
Speckled alder
7
Betula alleghaniensis
Yellow birch
5
Betula papyrifera
White birch
7
Comptonia peregrina
Sweet fern
7
Cornus alternifolia
Alt leaf dogwood
4
Cornus canadensis
Bunchberry 
X
Corylus cornuta
Witch hazel
4
Fagus grandifolia
American beech
2
Fraxinus nigra
Black ash
5
Larix laricina
Tamarack
9
Ledum groenlandicum
Bog Labrador tea
7
Lonicera canadensis
Fly honeysuckle
X
Myrica gale
Sweetgale
8
Ostrya virginiana
Hophornbeam
X
Picea glauca
White spruce
4
Picea mariana
Black spruce
X
Pinus resinosa
Red pine
8
Pinus strobus
White pine
6
Populus balsamifera
Balsam poplar
9
Populus grandidentata
Big-tooth aspen
9
Populus tremuloides
Quaking aspen
9
Prunus pensylvanica
Pin cherry
9
Prunus serotina
Black cherry
8
Prunus virginiana
Chokecherry
X
Quercus rubra
Red oak
7
Salix discolor
American willow8
Salix humilis
Prairie willow
9
Sambucus racemosa
Red elderberry
5
Taxus canadensis
Canada yew
2
Thuja occidentalis
White cedar
3
Tsuga canadensis
Hemlock
3
Ulmus americana
Elm
6
Vaccinium angustifolium
Lowbush blueberry
7





The other columns that I would like to see in here would be simple vs compound leaf, ring-porous vs diffuse porous, successionary stage, and dry vs wet habitat preference, freezing killing temperature, herbivore pressure, leaf drop date, flowering date, furthest north latitude, center of evolutionary group's range, among others. So it's a start, but for now mostly just pretty pictures and a cool table.

No comments:

Post a Comment