Living Lighter on the Land
The start of Autumn brings me a chance to reflect upon our busy Summer of gardening, field work, and internships at Pound Ridge Land Conservancy. Our programs of land protection and education depend upon the hard work of many helping hands, all of whom are learning to live lighter on the land. We received a grant from a local gardening club, Rusticus, that helped us to sponsor three wonderful summer interns. I will briefly summarize their projects here, along with the work of several volunteers who put in time and effort supporting our goals at PRLC. Stay tuned to our website, www.PRLC.net for greater detail on their accomplishments.
Tuddy (pronouced Too-dee) came to us from Columbia University Graduate School and completed an internship in Native Landscape Design. Her work was based at the Armstrong Education Center, where she analyzed site conditions and researched local ecology to find what plants would work best here to further our goal of establishing native plant gardens that benefit wildlife. She designed plantings for five micro-sites that can be used to educate other area landowners about how to augment the conservation value of their property, without attracting more deer. The over-abundance of deer in our area has resulted in decreased availability of food for other forms of wildlife, and Tuddy's plans address that issue with elegant style. Her designs do not require fencing and showcase plants with varying seasonal interest for humans and animals alike.
Nick grew up in this area and studies plant ecology at College of the Holy Cross. He conducted a baseline assesment of the vegetation community within our proposed deer-exclosure site at the Armstrong Preserve and documented seasonal change in the meadow community at Clark Preserve. Nick's meadow study plots were inadvertantly mowed by the landscaping crew of a helpful and supportive neighbor, but he responded adaptively, as did many of the plants in the meadow, making for a true learning experience. Nick's work will serve as a reference and guide for future projects to be completed at our preserves and on private properties with conservation goals.
Alizah is a rising senior at Fox Lane High School and has a vital interest in sustainability along with a strong work ethic. She provided consistent support in our organic garden, helping with planning, mapping, seeding, weeding, harvesting, and bug-control. She turned our compost and added it to the young and growing plants, watered when it was dry, and enthusiastically shared her learning with visitors to our garden. Alizah's interactive garden map will be used to plan next year's rotation of spring, summer, and fall crops.
Volunteers Kadijah, Scott, and Luke assisted in all of these projects, filling in the gaps to carry us successfully through the summer. Kadijah comes from an urban background and relished her time in the garden, absorbing information with spot-on precision. Scott is intent on learning the ropes of preserve stewardship and continues to provide invaluable help with meadow and forestry projects. Luke gained knowledge of landscape preservation in his hometown and helped to spread the word about our projects and the many events we host.
What is the common denominator that drives these young people's efforts? They are motivated by a desire to serve something greater than themselves, to provide for the greater good of their community and the larger world. Several of them were involved in the Boy Scouts of America as youth, and some continue to be and wanted to pass on this inspirational message to our readers:
"In addition to teaching kids about basic plant and wildlife identification, Scouting engages youth to make the smallest impact possible on the outdoors, to respect the life they encounter, to understand the man aspects of a healthy and balanced ecosystem, and to take the initiative in taking care of the environment in and around their communities. This summer, Pound Ridge's Scout 'Guy' completed a personal service project that earned him the rank of Eagle Scout, an achievement requiring hundreds of hours of service and self-directed commitment. He erected an information kiosk on the Armstrong Preserve that will serve to educate visitors for many years. Three of our other summer interns/volunteers were set on the path of environmental service through scouting and count their experience as a strong impetus for current engagement in conservation efforts. The excellent work done this summer by volunteer Scouts is a testament to the core values shared by these two organizations, and the magnitude of an effect thay have on young people."
I would like to express my sincere appreciation for the help of all our volunteers and interns this summer. I wish them the very best in their future endeavors within our community and beyond.
It always comes as a surprise to me that the first signs of Fall appear now, at the end of August. Sure, we can expect some more hot days, maybe even an Indian Summer, but the leaves are thinning out and beginning to drop already. You may sense a change in the light, which our trees respond to by ceasing production of chlorophyll in their leaves, revealing to us the brilliant colors of fall. Many of us wait for this time of year to find our favorite trees: we seek the red of oaks and cherry, the yellows of ash, hickory, birch, and poplar, or our real stunner, the red-orange-yellow leaves of the Sugar maple. I invite you to join me in practicing your tree identification skills on a Guided Walk and Talk in one of our most beautiful protected forests, the Richard's Preserve on Saturday, October 19, from 10am to noon. You can find information about other guided walks, and other preserves to visit, on our website www.PRLC.net.
You don't need to wait for the leaves to turn to start looking at trees, however. I have recently become fascinated by an aspect of trees that can be studied year-round, and with many stories to tell: their bark. Be it flaky, shaggy, craggy, or peeling, bark is an integral part of a tree's structure, much like the skin on your body. It serves to protect the trees delicate inner layers, where sugars and nutrients flow from roots to tip and back again. Native Americans used the bark of several tree species as powerful medecine, as well as for shelters and canoes. Bark can also help us to identify a tree's species, for every one of our 60 or so species here has a distinctive look that a trained eye can discern. This is especially useful in winter, or when the tree canopy is so high that we can't make out leaf shape.
The evolution of tree bark into its many forms is due to the particular pressures that tree species encounter, or once encountered, in their ancestral habitats. For example, the peeling, papery bark of birches is easily shed to rid the tree of epiphytic plants and mosses that tend to accumulate in the fog-shrouded forests where birches thrive. In areas that are prone to fire, trees like the Pitch Pine grow thick bark at a young age to survive searing heat. While thick bark serves to also deter many of the insects and fungi that parasitize trees, it also limits their expansion somewhat, and impedes photosynthesis. Some trees, like Beech, do photosynthesize through their thin bark, and this gives them a head-start on leaf-out for the summer. It also means that initials and such that are carved into Beech bark can last for the life of the tree, or hasten its demise by allowing entry of tree-killing pathogens.
Trees other than Beech respond to wounding much like your skin does, by growing a thicker layer over the wound. Study the scars on an old tree and you might find that it has withstood damage from hurricanes, fires, wire fencing, and even bear and buck rubbing. Buck will rub their antlers on trees to help them shed their velvet. With the overabundance of deer in southern New York, we find an abundance of Sugar maples afflicted by disease that enters through their wounded bark.
In a healthy ecosystem, bucks and trees can coexist because of a natural balance, the same balance that keeps insects and fungi from killing the trees they need to live on. Human impacts have altered our forest ecosystems in the Northeast to such an extent that equilibrium has been lost. We now face the imminent loss of a number of cherished tree species, including Ash, Beech, and Eastern Hemlock, due to invasive insects that have surmounted the protective layer of bark and tunnel within. The top recommendation for controlling the spread of such invasives as the Emerald Ash Borer, Asian Long-horned beetle, and Hemlock Woolly Adelgid is to never move firewood across property boundaries. Campgrounds such as Ward Pound Ridge Reservation now provide firewood as a deterrant to transporting it. To report a sighting of an invasive insect in New York, or to learn more, click here.
For more information about forestry, trees in general, and bark in particular, I highly recommend Northern Woodlands magazine, published quarterly by the Center for Northern Woodlands Education, Inc. I can't rave enough about what an excellent resource this has been in my own education and teaching career. Many thanks to Michael Wojtech, whose 2011 article on bark inspired me to look upon it in a whole new light.
Have you ever found an active bird nest? Most nests are temporary structures, meant to house only one generation before they are left to the mites and lice that accumulate in them. Even the most intricate and pain-staking nests are abandoned, except for those of raptors, who may reuse the same nest year after year.
Songbirds generally build more than one nest in a season, either to house successive broods or because one is damaged or predated. Because they are often hidden, either high in treetops or low under thick cover, the best way to find nests may be to watch the birds that use them. That is how I have been finding the nests around the Armstrong Education Center this summer. Monitoring their progress has been a wonderful lesson in ecology for my daughter and I, one that I would like to share with you. I was observing wildlife around the vernal pool at Armstrong when I found the first
nest, which was easy to see at eye-level in a young maple tree. I would likely have missed it had the mother not flown off as I approached. She was drab and not easily identifiable without a good head shot, so I tried to find out what she was by using the contents and make of her nest.
Some species make distinctively woven cups nests, like this one, while others make mud-and-stick structures, and still others use only cavities (the holes in trees). On this date, June 17, there was only one egg in the nest: whitish with a little brown speckling on one end. Over the next few days, more eggs appeared in the nest, but I didn't see the bird. On June 21, I took the photo above, in which you can see that one egg is different: it is a Brown-headed cowbird egg. Cowbirds are parasitic nesters, meaning that they do not make their own nests. Instead, they drop a single egg into the unprotected nests of other species, leaving the chick to be raised by its "adoptive" parents. I hadn't seen the host bird on the nest yet, but she won't sit until all of her eggs are laid, so that they incubate at the same rate and hatch at the same time. That way, the chicks have less time to attract predators to the nest before they fledge.
I was concerned about the cowbird egg in this nest. Cowbirds are big, about the size of a robin, and this nest was quite small. The parent, whoever it was would have a hard time feeding that big chick along with her three. Sometimes the smaller, weaker chicks are kicked out of the nest by the fast-developing Cowbird. I used a website run by Cornell's Lab of Ornithology to match the characteristics I had observed to likely candidates. I narrowed in on the Red-eyed vireo, a small forest bird that is very common in our area.
I had heard them singing all day for weeks, from high in the treetops, and I was surprised to learn that they generally nest much lower in the canopy, at a height of about 6 feet. You might have read in an earlier blog post, Late Spring Serenade, that birds sing to proclaim and protect nesting territory, thereby guaranteeing a food source for their young. I spied her on the nest on June 22, and she sat through June 26 (while her partner kept up his singing).
The saga of the Vireo nest was not lost on my eight-year old daughter, who once cried to me during a night-time thunderstorm, "can't we go put more branches out over the mother?" She was determined to take action against the cowbird egg. I tried to explain to her that human ideals of justice do not always apply in the natural world. Cowbirds do not make nests, not because they are lazy but because they evolved another strategy for survival, and they simply don't know how to make nests of their own. Without an occasional egg drop in a Vireo nest, we wouldn't have Cowbirds to enrich the web of life. That is difficult to understand for a child who does not especially care about something called a Cowbird. We went down to have a look at the nest. The mother was not about, and I lifted her up to look inside. Three chicks lay nestled within, pulsing with new life! We could only watch in wonder at their fragile strength, up against such a tough world.
On June 27, one of the Vireo eggs remained unhatched, and the Cowbird chick was perhaps twice as big as either of the other chicks. The next day, the fourth egg had hatched. The day after that, the Cowbird chick appeared about three times bigger than the others, and held its mouth open far above them. There was a lot of activity at the nest, with the parents flying in to feed them, so we went less often so as not to disturb them. On day four, July 1, there were still four chicks in the nest. On July 3, there were only two Vireo chicks left, and they looked too young to fledge. We searched the surrounding area and did not find any on the ground. On July 5, just one week after hatching, the nest was empty!
We hope they all made it. Red-eyed vireos and Cowbirds are two highly successful species in our habitat, evidenced by a second pair of vireos currently nesting by the Armstrong's garden in another young maple tree. They have three perfect eggs in their nest, and the female is now sitting.
Salamanders of Westchester County, New York
The northeastern region of the United States is home to vast numbers of a creature that many of us have never seen: the elusive, generally nocturnal, salamander. Our forest floors teem with these colorful animals on rainy warm nights, when they come out from underground and stream hideouts to prowl for insect prey. Salamanders are environmentally sensitive creatures and are considered to be indicators of forest ecosystem health, but they lack a voice (literally) and exist mostly outside of our consciousness. To protect them, we must remain conscious of their habitat requirements and preserve the conditions that foster them as an integral part of our forest web.
The New York State Department of Environmental Conservation offers opportunities for you to be involved in finding and recording the presence of wildlife, including a Citizen Science project to document salamander migration routes. They recently completed an inventory of amphibian and reptile species using input from thousands of citizen scientists over a ten years span. The Herp Atlas of New York documented twelve salamander species in Westchester County. One is considered to be endangered: the Northern dusky salamander, which inhabits rocky woodland streams. One of the most common, the Eastern newt, is often mistaken for a lizard in its juvenile life stage, and for an entirely different animal in its adult form (see pictures below).
As an aide to you in your search to discover these fascinating animals, I will summarize key points of the natural history of Westchester’s salamanders. I will group them into two main groups: those that are most often found in or near streams, and those that are more associated with woodland pools and deciduous forest floors. Salamanders are a type of amphibian, meaning that they breed in water. However, some of our local amphibian species bypass the aquatic larval stage, no longer relying upon wetlands for breeding, and most species can be found away from water at some point in their lives. For help with identification, I suggest this field guide: The Amphibians and Reptiles of New York State (2007).
I invite you to join me this Saturday (June 29) at 10am at the Halle Ravine Preserve for a Guided Walk and Talk focusing on amphibians and reptiles of the area!
Salamanders Commonly Found in or Near Streams in Southern New York
Northern red salamander (Pseudotriton r. ruber)
• Found in springs, brooks, nearby woods and meadows
• In leaf litter or under rocks
• Lays 50-100 eggs in fall
Northern slimy salamander (Plethodon glutinosis)
• Found on forest floodplain, ravine slopes
• Under flat rocks and rotten logs (nocturnal)
• Lays 6-36 eggs in rotting logs or underground
Four-toed salamander (Hemidactylium scutatum)
• Found in bogs, streams, floodplains, associated with sphagnum moss
• Under stones, in leaf litter in bog forests
• Lays about 50 eggs singly attached to moss or plants, close to water, in spring
Northern spring salamander (Gyrinophilus porphyriticus) northern subspecies
• Found in springs and mountain brooks
• Nocturnal, may prowl in rain
• Lays 11-100 eggs singly attached to undersides of stones in cool water
Northern Two-lined Salamander (Eurycea bislineata)
• Found along rocky brooks, river swamps, also in damp forest
• Life history still relatively unknown!
• Lays 12-100 eggs underwater in one layer, attached to rocks or plants, in spring
Northern Dusky Salamander (Desmognathus fuscus) * endangered in Westchester County
• Found in or along edges of rocky wooded creeks, springs
• Lays 12-36 eggs in grape-like cluster near water beneath rocks or in logs, in late spring
• The female stays and broods the nest
Salamander Associated with Woodland “Vernal” Pools and surrounding Forested Areas
These species breed in pools but may be found on or under the ground some distance from water.
Marbled salamander (Ambystoma opacum)
• Lays 50-200 eggs in a depression in Fall which later fills with water
• The female usually guards her eggs
Spotted salamander (Ambystoma maculatum)
• Lives underground, may be found in hardwood forest
• Lays cluster of 100 eggs attached to submerged branches in ponds, in March and April
Blue-spotted salamander (Ambystoma laterale)
• Found in deciduous forest
• Lays 6-10 eggs singly or in a small cluster, on pond bottoms, in April or May
Jefferson salamander (Ambystoma jeffersonianum)
• Found in deciduous forest, under debris near water
• Lays 10-20 cylindrical masses of 15 eggs apiece, attached to slim submerged twigs in ponds.
• Our earliest breeder, they migrate to pools in March when snow may still be on the ground.
Other Salamanders (and the most commonly found)
Northern red-backed salamander (Plethodon c. cinereus)
• Found in moist forest, coniferous and hardwood
• Lays 6-12 eggs under stones or in logs
Eastern newt (Notophthalmus viridescens)
• Also known as the Red-spotted newt, it has one of the most complicated life histories, having three distinct body forms depending on its developmental stage. Adults are aquatic and live in almost any unpolluted waters.
• Their eggs develop into a larval aquatic stage resembling a tadpole, which then undergoes metamorphosis to become an entirely terrestrial juvenile – little orange “efts.” These spend 2-5 years in forest litter and are often mistaken for a separate species from the gilled parents.
Late Spring Serenade
I have been settling into the swing of things at the Armstrong House for a few weeks now and I find my attention consistently drawn outside. At any time of day, morning or night, there are the chirps, trills, and calls that signal nature’s most abundant season. Who might there be, serenading outside your window?
Don’t assume that your troubadour is a bird, unless it is morning. As you probably know from experience, birds tend to sing early in the morning, with gusto, and then remain quiet the rest of the day. Most sing only during their breeding season, late April through July, to attract mates and also to defend their nesting territory from competition from other birds. A well-protected nesting territory ensures food for developing young. Alarm calls (which are very different from songs), are used by either sex and at any time of day or year. On a recent morning at the Armstrong Preserve, I heard American robin, Black and white warbler, Chipping sparrow, Downy woodpecker, Eastern wood-pewee and Tufted titmouse. In the evenings, a bird called the Veery sings a descending ethereal tune. Northern red cardinals may sing at any time of day, or year, in our area.
Chances are you have birds around your property, but they are not the only songsters out there. You may be hearing trills from the Common gray tree frog this month, which many people mistake for a bird. Tree frogs are nocturnal and generally very secretive, spending most of their lives high in the tree tops. At this time of year, adult male frogs call in the evening (click here to hear it). When spring rains fill their breeding pools, like our vernal pool here at the Armstrong Education Center, the frogs descend to lay and fertilize their eggs in the water. Tate wrote about two other frogs that depend upon vernal pools in the May 25, 2013 post of this blog. They were the Wood frog and Northern spring peeper, and peepers can still be heard early this month. If you would like to learn more about these fascinating animals, join us on Saturday, June 29, 2013 for a guided nature walk at one of our preserves in Pound Ridge, Halle Ravine. If you have a wetland on your property or an interest in preserving these valuable habitats, please attend our Land Stewardship in Action Workshop on Saturday, November 2, 2013 (location to be announced on our website).
The Common gray tree frog lives in forest, even suburban forests, where vernal pools are present.
They can be gray, green, brown, or nearly black, and measure up to 2 inches long.
Tree frogs change color for better camouflage against tree bark.
Another source of beautiful music (to the trained ear, perhaps) are the insects. Like birds and frogs, insects call only during the brief window of their specific breeding season. So far, we have heard the Spring field cricket, a species of katydid, and a few different grasshoppes. In other parts of New York, Cicadas are making big news (and big noise). For information about the current cicada emergence, click here. Many of us associate these sounds with hot summer nights, but by summer, our current singers will be replaced by later-breeding species such as the Snowy tree cricket. Their “chirp rate,” or song speed varies with temperature, and old-timers and naturalists can often guess the date by who is singing from the treetops. Join us for a fun Friday night at the Armstrong Preserve, July 19, 2013 for a guided tour of the sounds of Summer.
Watch a video of the Snowy tree cricket singing here
I hope you have enjoyed this musical tour of our local woodlands, and I hope it inspires you to spend a few minutes listening out your own window. Consider that each and every member of this chorus is integral to the great hum of life, and requires healthy, intact habitats to survive. Rachel Carson, the renowned biologist and conservationist, wrote in Silent Spring, “The more clearly we can focus our attention on the wonders and realities of the universe about us, the less taste we shall have for destruction.” Like the taste of a peach in summer, these sounds can bring you back to simpler times and to a stronger connection with the natural world.
Hi from Krista- Your New Land Steward: On My First Day in the Garden!
Hi, I’m Krista Munger, the new Land Steward/Educator in residence at the Armstrong Education Center here in Pound Ridge. Tate is off to Alaska, and has passed his Living Lighter on the Land blog to me so I might continue to share with you tips, stories, and practical information guiding our work at the Center and in your backyard.
To introduce myself, I have worked as a biologist and educator in the Hudson Valley since 1997.
I hold degrees in conservation biology and in adolescent science education. From 2002 to 2005, I lived and gardened at the Arthur W. Butler Memorial Sanctuary in Bedford, NY. When my daughter was born, we moved to Woodstock, New York to be closer to the mountains, but now we are thrilled to return. There is an old saying that you can never come home again. I have also heard, “never look back”. Well– we have done both! I am happy to report that little has changed, except that ground cover is increasingly dominated by invasive species like Japanese barberry and Japanese stilt-grass and recent storm damage to trees and soil stability is evident. Tate addressed problematic invasives and methods for controlling them in his blog post on April 9, 2013. I will return to the persistent dilemma of invasives in future blog posts.
The landscape of northern Westchester County is still lush and idyllic, perfectly suited for humans and for many kinds of wildlife. I am afraid this would not be true without the tireless work of local conservation groups and their partners. In this blog and through our programs at the Armstrong Education Center recently started in the Spring of 2012, we go beyond the more traditional work of land protection to focus on human relationship with nature and highlight how our daily lifestyle choices impact local ecosystems. We recognize that the quest to live more harmoniously with nature is never-ending, and there is much to be learned (and re-learned).
I experienced something like this on my first day in our community vegetable garden at Armstrong. I had visited the garden previously on a tour of the outdoor classrooms at the Center, and surmised from Tate that I should be prepared to hit the ground running. It seems that no matter how much garden planning we do in February and March, the month of May is always a mad rush to get plants in and weeds out. This is only the second growing season at the Center’s garden so there is more preparatory work to do than should be necessary in later years. On first day, I was going to show how productive I could be. The first order of business was to attack the mass of early spring arugula that had gone to flower. Behind it, the kale was in flower too. Greens that have bloomed have a bitter taste and are generally considered undesirable as they continue to draw nutrients from the soil and can drop seed where you don’t want it. I ripped most of these flowering unwanteds out and added them to my compost pile.
Then I noticed a bee–a honeybee from our own hive at the Armstrong, visiting one of the flowers I missed! (See April 2012 Blog Post). I sat back and watched as another came and stuck its face deep into the yellow flower center. It occurred to me that in my haste to ‘clean-up’ the garden, I had removed a food source for the bees! Bees need a variety of nectar sources and are especially vulnerable to food shortages at the beginning and end of summer, when temperatures vary widely and blooming can be sporadic. I looked around and didn’t see much else in flower aside from dogwood and an apple tree. Their blossoms provide good nectar, but still I regretted my singular focus. I wish I had thought more about what I really want to accomplish here: a working landscape that provides for the wildlife as much as for me. This is the basis of permaculture and is one of our goals here at the Armstrong Education Center.
Our 2012 Garden Student Intern, Gabby S. described our intention best in her report. She said, “our concept of an interrelated, multi-part garden is guided by the principals of permaculture, where garden elements work together to produce greater productivity and reduce waste. Multi-part gardens are practical and sustainable since each part uses another’s waste as an input, reducing the need for outside resources. For example, instead of purchasing all of our fertilizers and soil conditioners, our composting system allows us to inexpensively improve our soil.”
Tate drew up a schematic of the inputs and outputs of our system, and how they are related which I have included here. The bees may very well have enough forage from the tree blossoms abounding, but I’ve still learned my first lesson on my first day of work! I am going to try to be more thoughtful about the overall effects of my actions, in the garden and beyond! This means that the focus has to be on the health of the interconnected natural web or system in my backyard and garden, more than on the appearance of things. Please, if ever you hear of my unruly arugula here in the Armstrong educational garden, know that I am letting it go for the bees at this time of year!
The past month has been busy at the Pound Ridge Land Conservancy. I've been knee deep in logistics preparing for a series of public workshops focused on planting trees, shrubs and flowers. Now that the events are past and the plants are in, it is time to share with you our work.
April 13: Stewardship in Action, Managing your meadow for fruit and wildlife
During this workshop we took the next big step in our ongoing meadow management, which aims to revitalize the shrubby edge of the meadow with native and edible plant. We planted 10 northern bayberry shrubs, which produce small edible fruits that birds go crazy for. Over time these bayberry will grow into a dense stand to provide a zone of cover to wildlife between the meadow and the forest. We will continue to plant northern bayberry along the meadow's perimeter until we have replaced all of the Japanese barberry that currently grows there. We also planted an heirloom apple tree and two paw paw trees in the part of the meadow with the most amount of direct sunlight. We chose these trees to demonstrate the productive potential of an open meadow and to increase the productivity of the Armstrong Preserve's working landscape. These trees will grow to provide fruit to the occupants of the Armstrong House and along with the rest of the working landscape (organic gardens, chicken flock and honeybee hive) will supplement trips to the grocery store.
Below: Alan Haigh, from the Home Orchard Company, planting an heirloom apple tree in the Armstrong Preserve's meadow
April 27th: Gardening workshop at Sara Stein's Garden.
Before she died, botanist and writer Sara Stein lived in Pound Ridge where she transformed her ~3-acre suburban property into a diverse natural haven for birds, bees, flowers and native plants. We used the Sara Stein Garden (now in the hands of a generous Pound Ridge family) as the backdrop for two gardening workshops aimed at incorporating native plants into your home's garden. Led by local garden designer and Chair of Bedford Audubon's Leon Levy Native Plant Garden, Lynn Becker, these workshops were a huge hit. Workshop participants toured Sara's garden before getting their hands dirty and planting new beds of bearberry, indian pink and blueberry. As a group we discussed the advantages of gardening with native plants (for example, natives are well-suited for our soils and envionment and native plants carry out associations with wildlife that imported plants sometimes cannot) and shared resources on native plant purveyors. We look forward to getting back to the Sarah Stein Garden for another workshop soon.
April 28th: Replanting Carolin's Grove
Carolin's Grove is a 5-acre preserve dominated by Norway spruce trees on Stone Hill Road (Rt. 137) in Pound Ridge. Hurricane Sandy toppled dozens of spruce trees in the grove and left big openings in the forest canopy. Under these canopy openings we planting 150 small saplings which will utilize the sunlight reaching the forest floor and grow to fill in the forest. To deter deer from munching on the new saplings we choose white spruce and pitch pine (both of which are not favored by deer) and placed most of the saplings in areas that the deer will have a hard time reaching.
This new age class of spruce trees will add some diversity to the grove, which is currently comprised of similarly aged trees (all around 80 years old). It is important to have multiple age classes in a forest to provide a variety of habitat to wildlife and to ensure that smaller trees will always be available to grow into newly formed openings. In this sence, Hurricane Sandy was beneficial to Carolin's Grove. We will allow the dozens of downed trees and branches to decay on the ground because they will provide carbon and nutrients to the soil and habitat to a whole suit of small animals.
Below: PRLC board member, Jim Evans, plants a white spruce sapling in Carolin's Grove.
We conduct our land stewardship in a way that is demonstrational, educational and exciting. If you are looking to increase the value of wildlife habitat on your property, become more sustainable or support declining populations of native plants then join us on one of our workshops. Look for the tagline 'Sewardship in Action' for our series on property management (next workshop: June 8th). Check our event calender for event postings. Stay tuned!
Lets think of all the mammals that currently inhabit Pound Ridge, NY: chipmunk, grey squirrel, mice, vole, groundhogs, moles, opossum, cottontail rabbit, raccoon, red fox, gray fox, bobcat, mink, white tailed deer, bats, coyote and bear. Now think of the additional mammals that were here before the eastern forests were cut down: there were mountain lion, wolf, porcupines, beaver, woodland elk and weasels of all sizes. When you stop to list them all, this diversity seems impressive. It should be obvious this wildlife diversity varies greatly from place to place and depends on the presence of suitable habitat.
Consider our Lower Hudson/ Southern New England/ NY Metro region and all of the landscape pieces that make it up. We have cities, state parks, county parks, small lot suburbs, large lot suburbs, farms of all sizes, pasture, orchards, wooded wetlands, lakes, ponds, rives, stream, town centers, tree farms, and (thanks to groups like PRLC) small nature preserves. As you can see, there are a lot of different places for our mammals to live and each of these landscape pieces support a unique diversity of mammals.
For example, the diversity of mammals in Van Cortland Park is expected to be lower than that in Ward Pound Ridge Reservation. Certain mammals need large tracts of land on which to roam (bobcat, for example), while other animals do fine in a heavily fragmented suburban setting (such as the white footed mouse).
Here is the $64,000 question: does a place’s diversity affect how that place functions? For years Dr. Richard S. Ostfeld from the Cary Institute of Ecosystem Studies has been asking this question. Specifically, Dr. Ostfeld studies the ecological components that contribute to Lyme disease risk across the tri-state region. His findings are shocking! In a nutshell, here is what he has concluded:
First, a bit of background:
Back legged ticks (Ixodes scapularis) carry a spirochete (Borrelia burgdorfii) which, when entered into humans through a bite, causes Lyme disease. These ticks are not born with the spirochete, they must pick it up from a vertebrate (commonly a bird or mammal) during a blood meal. The animal that initially gives the spirochete to the tick is called a reservoir. Just stop here for a second. This is an important piece to understand. Without the reservoirs, ticks in Pound Ridge wouldn’t carry the spirochete that causes Lyme disease. It is the reservoirs that keep infecting new generations of ticks with the infectious spirochete.
Now on to Dr. Ostfeld’s research. He has found that:
1) Not all potential reservoirs are equally good at giving the spirochete to ticks. Specifically, ticks that feed on white footed mice are very likely to obtain the spirochete during their blood meal, whereas ticks on opossum are much less likely to obtain the spirochete. (*The reason behind this is not totally understood but it likely has to do with the reservoir’s immune system*). This means that we would be better off with less mice and more opossums. There’s more.
|This cartoon shows the differences between two disease reservoirs|
2) Reservoirs vary in the amount of ticks that they carry. Specifically, the average mouse carries roughly 50 ticks whereas the average squirrel carries roughly 150.
3) Reservoirs vary in the amount of ticks that they remove from their body. Specifically, mice remove far fewer ticks from their body than opossums.
|A white footed mouse with an ear full of ticks|
4) A tick’s chances of surviving the winter (an important component of their life cycle and therefore, disease transmission) depends on where it obtained its pre-winter blood meal. Specifically, mice-fed ticks survive the winter better than opossum and squirrel-fed ticks.
From these findings we begin to realize that it matters very much which animal an uninfected tick feeds on. Now on to the question of diversity. If it matters which animals an uninfected tick feeds on and we know that different places have different groups of animals and levels of diversity, can we then begin to predict which places are more likely to have infected ticks (and sadly, infected humans)? This is exactly what Dr. Ostfeld has done.
As diversity declines, disease risk goes up.
Think about it this way: as a forested landscape gets fragmented by development the first animals to be lost are those that are long-ranging – animals like the bobcat and bear that just love to roam. As we continue to whittle away at the landscape animals drop out in a predictable pattern based on their habitat requirements such as area, cover, and food source. Some animals do very poorly in the modified environments that are now common throughout the region while other animals do very well. You don’t see a lot of porcupines around your house but you do see a lot of chipmunks, right? What Dr. Ostfeld has discovered is that the species that thrive in our fragmented and human dominated environments (specifically, the white footed mouse) are the most efficient disease reservoirs. His research shows that as animals are taken out of an ecosystem (aka, as diversity decreases), the risk of Lyme disease goes up. He also shows that as predators are removed from an ecosystem the number of mice (very efficient disease reservoirs) goes up.
For these reasons, managing for vertebrate biodiversity should be a priority. Predators like the red fox and bobcat are important in keeping down mice populations and critters like raccoon and opossum are helpful in diluting the reservoir effect or Lyme disease. It makes me happy to know that the compost at the Armstrong House is visited by raccoons and opossum!
Its official, spring has arrived: the pheobes are back, I heard an american robin singing, the leaves of the trout lily have emerged and I saw a red maple in bloom. In the coming weeks the forest will green out and it will start with the Japanese barberry. This shrub (originally from Japan and eastern Asia) is one of the first plants to push forth its leaves. For someone suffering from the winter blues the early-spring color of Japanese barberry can be quite welcoming but unfortunately there is a downside to its leaves.
|Japanese barberry leafs out while most of the forest remains dormant|
If cutting is your method of barberry managing, now is a great time to get out your tools. Hit the plant before it leafs out to 1) prevent it from building up a tick-friendly microclimate and 2) prevent it from photosynthesizing (growing). Cut every winter/spring until the plant gives up. By continued cutting you are forcing the roots to resupply the shoots. If you keep taking the shoots, the roots will shrink and eventually poop out.
This problem isn’t going away. Take up the fight, at least on your own property.