Showing posts with label Naturalist Certification Field Trips. Show all posts
Showing posts with label Naturalist Certification Field Trips. Show all posts

Thursday, November 7, 2013

Trees and Shrubs





I was unable to attend the Trees field trip on September 14. I am making up the trip by describing some of the trees I saw in different parts of New Castle County over this past year. 

1. Osage Orange (Maclura Pomifera): As we learned on the Mammals trip, some Native Americans considered the hard wood of this tree the best for making bows. It's also called a "hedge apple" because of its odd-looking fruits. Although the trees are actually native to the Midwest United States, they work well here. They were brought in to provide windbreaks for farm fields. Now, as part of a hedgerow habitat, they provide an important food source for white-tailed deer and a good shelter for birds. According to Dave Bartoo, who tends trails at White Clay Creek, the Osage Orange stumps seen here show no signs of decay even though the trees have been cut down for years.

Osage orange trees, White Clay Creek State Park, 19 September


Osage orange fruit


2. American Sycamore (Platanus occidentalis): Sycamores can be identified by their patchy bark. Sycamore bark is more rigid than that of other trees, so it tears off as the tree grows.


Sycamore leaf




3. Bigtooth aspen (Populus grandidentata): Some very interesting information about these trees can be found here: http://www.rook.org/earl/bwca/nature/trees/populusgrand.html
This site explains that aspens are most successful after a disturbance like a fire. They put out suckers which grow into clones of the original tree.

In Yellowstone National Park, the reintroduction of wolves actually helped the aspens recover: http://www.sciencedaily.com/releases/2007/07/070726150904.htm

Bigtooth aspen, 25 October 11:59 AM
4. American Beech (Fagus grandifolia) The beech tree has an edible nut, also called "beech mast."
The tree is highly tolerant of shade. 

American beech, Lums Pond State Park, 24 October 11:23


5. American Holly (Ilex opaca): This is the state tree of Delaware. 



10 November 2013



Holly branch














6. Maples (Genus Acer): Sugar maples, red maples, boxelders, and Norway maples all seem to be well represented in the leaf piles I have walked through recently. Although maple trees are common and familiar, the family has some unusual members: two maples are evergreen instead of deciduous, and some maple leaves look nothing at all like the sharp-lobed leaves in our backyard: http://en.wikipedia.org/wiki/Acer_laevigatum
Boxelder (Acer negundo) and silver maple (acer saccharinum) leaves, 1 November 11:47

Boxelder, Lums Pond State Park, 1 November , 11:01 AM
Norway maple (Acer platanoides), 1 November 



7. Green Ash (Fraxinus pennsylvanica): The Green Ash is threatened by the Emerald Ash Borer (Agrilis planipennis), an invasive beetle. Purple EAB traps (like this one http://www.fairfaxcounty.gov/news/2009/emerald-ash-borer-traps-out.htm)
can be seen hanging over streams in Delaware.
Lums Pond State Park, 1 November 11:25 AM
T
8. Pitch pine (pinus rigida) The wood and pitch of this tree were once used for shipbuilding.
Pitch pine, Lums Pond State Park, 1 November, 11:30 AM
The trunk of this conifer--are the white spots caused by pine beetles?


9. Sweetgum (Liquidambar styraciflua): Each point of the sweetgum gumball opens to let out two seeds (according to http://www.fcps.edu/islandcreekes/ecology/sweetgum.htm)

Sweetgum leaf

Sweetgum gumball, Lums Pond, 1 November, 11:11 AM


Sweetgum tree in front of my apartment, 7 November,7:38 AM





10. Crabapple (wild apples in the family Rosaceae): Crabapples are the wild forebears of domesticated apples. The apples can be used to make jelly.

Crabapple, 19th September 3:20 PM
11. Black Walnut (Juglans nigra): The black walnut likes lots of water and light. It is native to the Eastern U.S., but one of the largest black walnut trees is on Sauvie Island in Oregon: http://ascendingthegiants.com/news/6/52/Black-Walnut.html


4 May 2013

12. Yellow poplar/tuliptree (Liriodendron tulipifera): This tree is not actually a poplar, but a relative of the magnolia.

The tuliptree is the tree on the left.

This gives you an idea of the tuliptree leaf's shape, if not the color.



13. Sassafras (trees in the genus Lauraceae): Sassafras trees have leaves with different numbers of lobes. On the same tree, there are oval leaves, bilobed leaves, and trilobed leaves like the one below.
Sassafras leaf found 11 October around 12:00 PM


14. Buckeye (Aesculus glabra) The buckeye tree can be identified by its spiny fruits. They look like horse chestnuts. Information on telling the buckeye from the horse chestnut can be found here: http://www.extension.umn.edu/yardandgarden/ygbriefs/h401chestnuts.html
Bellevue State Park, 13 September 10:30 AM

15. American chestnut (Castanea dentata) This tree is in front of the office at Lums Pond. American chestnuts are scarce because of the chestnut blight, but there are still some healthy ones. This one may be a showcase tree for the park.

Leaf of an American chestnut (Castanea dentata)  4th November, 10:04 AM
16. Swamp White Oak (Quercus bicolor): White oak leaves have rounded lobes, while red oak leaves have pointed leaves.

25 October 11:58 AM

Chestnut oak leaf (Quercus Prinus), I think







A few more leaves and trees I have yet to identify:


1 November, 11:22 
 September 

Lums Pond State Park, 4th November, 10:04 AM



Lums Pond State Park,1 November 11:34 AM



Sunday, September 29, 2013

Aquatic Ecology

Elizabeth Osborne

28 September
9AM

Ashland Nature Center
Hockessin, DE

On September 28th, the Naturalist Certification Class, led by Kristin Travers, did a survey of the Red Clay Creek to determine its health and learn some things about aquatic ecosystems.

Just looking at Red Clay Creek, one can see that it's a likely place to find macroinvetebrates. The movement and clarity of the water shows that there is oxygen in the stream. In addition, the stream is healthy enough to support vegetation on either side.

For comparison, here is a creek at Lums Pond that does not have as much oxygen, but does have healthy vegetation. The low oxygen in the stream makes it an unfavorable habitat for fish, but, like Delaware's inland ponds, a good place for reptiles and amphibians.



Still stream

When I dug up some of the sediment from the bottom of the creek, I didn't find any living organisms.



Riffles are the best place to find macroinvertebrates--they are places where the current is interrupted by rocks or logs, creating a safe habitat for the small organisms to hide and cling. In fact, the macroinveterbates we found tried to cling to anything they could find in the trays, including each other.

At Red Clay Creek, we used simple tools to survey the living organisms in the water: nets, small plastic containers, buckets, and out feet to stir up the sediment.


Using the net
Sorting through to see what we found

Kristin also had a scope we could look through:


When we had gotten some organisms in the bucket, we left the creek and deposited them in ice cube trays to sort them.
Leaving the creek

Here are the organisms we found:

Damselfly larva (Damselflies, like dragonflies, are in the order Odononata)


Two damselfly larvae
Water penny (larvae from the family Psephenidae)
Planaria (non-parasitic flatworm)

Another damselfly larva
The Big Three of stream health are the larva of the cranefly, stonefly (order Plecoptera), and mayfly (order Ephemeroptera, literally "wings that last a day"). These are indicator species because they can only live in very healthy water. Although we found only one or two of each of these, Kristin told us that ten years ago, there would have been none. Red Clay Creek has been undergoing rehabilitation since its time as a dump stream for industrial chemicals in Wilmington. There should be more mayflies, stoneflies, and craneflies, but it's a start.
Cranefly larva (members of a family in the order Diptera)
Another view of the cranefly larva
Crayfish
 
Scuds

Stonefly larva
Orange caddisfly larva

 

Underside of dragonfly larva, showing powerful jaw



 
Diana's waders did not pass the test