Tuesday, April 24, 2012

Pink Surprise

Last Saturday morning (April 21), Kali and I took a 1.5-hour walk along "my" creek, but several miles downstream of "my" natural area.  This section of the creek flows through public parkland, and is paralleled by a well-used and popular bike path.

Since the creek is flowing through the Piedmont, the topography is rolling.  As Kali and I "summitted" the highest hill along the bike path (about 50 feet above the creek), a knoll which provides my favorite viewpoint in the entire 21-mile stream valley, we stopped to enjoy the vista and I was astonished to see native azaleas blooming on the very steep hillside below us.  This azalea is also known as pinxter-flower, pinxter-bloom, and election pink (Rhododendron periclymenoides).  The occurrence of the plant, which should be a typical and significant component of the woodland flora, surprised me because most showy plants in the park fall victim to human abuse if they haven't been eaten first by the very abundant deer.  I suspect that these plants have persisted only because the hillside is so steep--although there were obvious paths through the stand.

How about that name?  Azaleas belong to the genus Rhododendron, and periclymenoides means honeysuckle-like.  But pinxter-bloom? Because it’s pink?  According to the Sierra Club Potomac Hiker's Handbook:
The term is of Dutch origin, a shortened form of Pinxter blomachee, which translates roughly as 'blossoming on the Pentecost.' The Dutch settlers of the Hudson River valley noted that the flower reached full bloom near the date of this important Christian festival.
We descended the other side of the knoll and continued our walk, crossing to the opposite side of the creek on a very busy road bridge high above the stream.  We decided to return on the opposite (non-bike path) side of the creek.  While there's no paved path, there is still a well-used footpath along the creek.  Nevertheless, we startled a female Canada goose who was sitting on her nest full of eggs less than two feet off the trail and three feet above the water.
A view upstream from the bridge

Monday, April 16, 2012

Talking Trash and Getting Goat

A very small sample of the trash scavenged from the creek

We held our annual creek clean-up on Saturday, April 14.  About 115 volunteers came out on a beautiful spring morning to scour three miles of streambank for trash washed down from the upper watershed by the twin tropical storm floods we experienced last August and September.

The clean-up is our organization's biggest annual event in terms of attendance, but 115 volunteers is a smaller group than we usually attract.  It's a two edged sword, though; on the one hand fewer volunteers means that we collect a smaller volume of trash, while on the other hand, a smaller group is much easier to manage.  Actually, the trash-per-volunteer ratio seemed just about right this year.

I escorted a small group to clean up The Mysterious Island (see February 25 post).  Unfortunately, though we've had almost no rain this spring, the creek was still too deep for most members of the group to get across, so they cleaned the trash on the mainland and another fellow and I excavated tires, wood, and plastic debris embedded in the logjams that resulted from the flooding.  My most interesting find was a Nikon camera (sans guts).  In trading stories with other volunteers during the picnic lunch afterward, the best finds of the day were a gasoline powered lawnmower and soft drink vending machine.
Kali with a full load

On another front, my land stewardship staff has purchased four goats that we will use to clear invasive, non-native plants and underbrush.  The goats have been on site since last Monday (April 9) and are getting used to their surroundings.  They'll be set out into the field today to begin eating their way through multiflora rose, Asian bittersweet, and porcelainberry.  Kali has named them Mustard (for garlic mustard), Rosie (for multiflora rose), Honeysuckle (for Japanese honeysuckle) and Babe (because this goat is especially affectionate).  Stay tuned for updates.
Rosie (top) and Honeysuckle

Monday, April 9, 2012

Eastern Easter

Kali scanning the ocean for surf ducks at North Brigantine Natural Area

You can't get much further east than the Atlantic coast, so Kali and I had an Eastern Easter this last Sunday.  We had so enjoyed our visit to the Edwin B. Forsythe National Wildlife Refuge on New Year's Eve that we decided to make the 2-hour drive to the New Jersey shore on Easter.  The day was nearly perfect--temperatures in the upper 60s, cloudless skies, and low humidity.  The only drawback was a strong wind that chilled us if we stood in one place for too long.
Atlantic City across the marshes

Most of the very abundant wintering birds had left the refuge, and the refuge managers had drawn down the water levels in the impoundments, but we still had plenty of birds to observe on the 8-mile Wildlife Loop road through the refuge.  Osprey pairs were using every available nesting platform.
Osprey (Pandion haliaetus)

Though very common, I had a chance to get a good shot of this adult Herring Gull diving for crustaceans.
Herring Gull (Larus argentatus)

A small flock of Snow Geese, which numbered in the thousands in the winter, still hadn't flown north to their Arctic wintering grounds.
Snow Geese (Chen caerulescens)

The highlight of the day, though, came right at the end of the drive when a flock of Glossy Ibises, recently arrived migrants, flew to the edge of one of the impoundments.  There were at least a dozen birds combing through the muck in search of food.  We hadn't seen these birds since we left Florida 24 years ago.
Glossy Ibises (Plegadis falcinellus)

We had lunch at the edge of a freshwater pond at the refuge.
Holding onto her cap in the strong breeze

Then we drove off the mainland and onto Brigantine Island, a barrier island just north of Atlantic City.  The southern end of the island, adjacent to Atlantic City, is densely developed.  Somehow, the northern third of the island was protected as the North Brigantine Natural Area.  While vehicles are allowed to drive out onto the sand, the beach and dunes remain nearly natural.  When sensitive bird species are nesting in the summer, the beach is closed to vehicles.  We walked about halfway out to the end of the island.
Few walkers venture beyond the condos and motels on the island

 A maritime Stonehenge at North Brigantine Natural Area

Wednesday, April 4, 2012

Wissahickon Wetland

Killdeer (Charadrius vociferus) See end of post.

I am adjunct faculty at a local university this term, teaching undergraduates about ecological restoration.  Most of the class time consists of lectures, but on Thursday, April 29, we visited a wetland restoration project.

This project lies on the floodplain of Sandy Run, the largest tributary of Wissahickon Creek, which is itself a tributary of the Schuylkill River in southeastern Pennsylvania.  Like all of the streams around Philadelphia, the Wissahickon and its tributaries are heavily urbanized and very "flashy" (i.e., they have low baseflow between precipitation events because groundwater recharge is limited by the imperious surfaces in the watershed, and they become roaring torrents after storms because so much water runs directly off the pavement and rooftops and into the streams).

The Wissahickon Valley Watershed Association received a $40,000 grant to convert a perennially soggy softball field adjacent to Sandy Run into a wetland.
The original plan for the project called for the creation of a seasonally flooded wetland that would dry out between storms.  But, once excavation got underway, the planners found that the groundwater level was higher than they had anticipated, so the basin was perennially flooded.  Instead of a seasonal wetland, they created an emergent marsh.
Emergent marshes aren't "bad" but, because they hold water all the time, they allow for the colonization of fish, which are amphibian predators.  Thus, the habitat is not as desirable for amphibians as a seasonal wetland would be.  In a second phase of the project, the planners "got it right," and created shallower depressions above the water table that only hold water after storms.

Between the created wetland and Sandy Run lies a mostly wooded riparian zone.  Floods have deposited gravel and sand from the stream into a low dike adjacent to the stream channel, and that berm has been colonized by scrubby box elders and sycamores.  The floodplain as been invaded by the non-native invasive buttercup, lesser celandine (Ranunculus ficaria), and by pernicious purple loosestrife (Lythrum salicaria).  As part of the wetland restoration project, the planners also planted trees on the floodplain to augment the riparian buffer that had developed naturally.
All of the trees have to be caged to protect them from deer damage.  Bob Adams, Director of Stewardship for the Watershed Association, showed the students how the cages are subject to damage from floods and how they snag debris washed downstream during storms.

And, the Killdeer...

As the field trip was winding down, I heard the distinct call of a Killdeer, but didn't give it much more than passing notice.  Then, I saw a group of students gazing down at the ground, captivated by something.  When I went to investigate, I discovered a Killdeer sitting on the ground, and I was able to get within three feet of the bird, which didn't move a muscle.

Floods associated with Hurricane Irene and Tropical Storm Lee late last summer had washed gravel off a parking lot and deposited it in a think layer adjacent to the wetland restoration project.  It provided perfect nesting habitat for the Killdeer, which wasn't about to be moved off her territory.  I despair for the bird's success, though; the site is very near a very busy road, and people use the trail through the wetland for recreation and to walk their dogs.

Monday, April 2, 2012

Bronx River Restoration

The Bronx River in Bronx River Park.
The rock vein on the right side of the image is an in-stream habitat improvement structure.

On Saturday, March 24, I took a tour of three restoration sites along the Bronx River in New York as part of the Society for Ecological Restoration's Mid-Atlantic/New England chapter conference held the previous day at Brooklyn College.

The Bronx River (a creek, really) rises in Westchester County north of New York City and flows 23 miles to its mouth at the East River.  The lower half of the watershed lies in the Bronx, where the stream is tightly confined to a narrow riparian corridor hemmed in by the Bronx River Parkway and the commuter railroad line serving the northern suburbs.  The watershed is fully urbanized/suburbanized, so the stream is "flashy" (i.e., it floods readily and rapidly during most rain events because of the extensive impervious cover throughout the watershed).

Our first sop was in one of the New York City parks, Bronx River Park, just north of the New York Botanic Garden and the Bronx Zoo.  There, members of the non-profit Bronx River Alliance and New York City Parks' Natural Resources Group showed our group a perennial wet cricket pitch that had been converted to a flood detention basin densely planted with willows and other native trees.  Then, our group walked a bit downstream to view areas where Japanese knotweed (Fallopia japonica) had been uprooted and replaced with saplings of native trees.
With traffic on the Bronx River Parkway roaring in the background,
a new riparian forest is growing on the floodplain (covered with invasive lesser celandine (Ranunculus ficaria).

After restorationists hand-dig out Japanese knotweed,
they lay down a layer of fabric and plant new tree saplings in holes in the cloth.

Our second site was further downstream, outside the park.  Behind a huge home furnishing and carpet store called ABC, we visited a restoration and art installation called WaterwashABC.  Environmental artist Lillian Ball has created environmental art installations called "Waterwash" in various locations, all of which serve to clean stormwater runoff in an aesthetically appealing way.  At WaterwashABC, Ball replaced an unsightly, rubble-filled, invasive-dominated slope leading down to the Bronx River behind the ABC store with an attractively landscaped water-permeable pathway leading down to a long, narrow stormwater wetland that receives all of the runoff from the store's parking lot.  The wetland vegetation will remove sediment, nutrients, and pollutants before the water enters the Bronx River.
The porous pavement walkway, surfaced with recycled crushed glass, 
leads down to the stormwater wetland observation deck behind the ABC store.
The stormwater wetland was installed last summer.  Across the Bronx River, 
the city has converted an old cement factory to Cement Factory Park.

Our third stop was a salt marsh restoration site at the mouth of the Bronx River in the city's Soundview Park.  Nearly all of the tidal wetlands in New York have been filled to create developable upland, and the city is trying to recover some of the lost habitat to improve water quality.  At Soundview Park, the U.S. Army Corps of Engineers excavated countless yards of fill to create new tidal wetlands.  Most of the fill was used to build-up a derelict area of the park that had become overgrown with invasive plants.  The filled area will be restored to upland forest.
New York City Parks personnel discussing the wetland restoration project.  All of the area to the left of the group, out to the orange fence line in the water in the background, has been excavated to re-create wetland.
The upland area where the excavated fill was spoiled.  The fill was covered with a combination of compost and good, clean soil.
The recreation path temporarily closed wile the wetland restoration work is underway.  The brown hill on the left is the compost that is mixed with clean soil and used to cover the excavated ill.  The boulders were all removed from the wetland restoration site and will be moved off site.