Tuesday, March 27, 2012

To mow or not to mow- that is the question

This post follows the recent thread about habitat fragmentation and managing your backyard with an eye towards the organisms that live there.  Just a brief recap on the issue: through intense urbanization and its sprawl large pieces of intact landscape  (forests, meadows, wetlands) have become less common.  This leaves thousands of small patches of wild land across the landscape, which means: our backyards are the ecosystem, the ecosystem is our backyard.  Our backyards have therefore become places relied on by wildlife (bugs, birds, trees, bacteria, worms, fox, coyotes, etc) and our management actions (mowing, planting, cutting, spraying, gardening, bee keeping, etc) affect their survival.

The commonly cultivated and manicured lawn is an intensely managed landscape that does little to boost the vitality of our backyard ecosystem.  If you compare the ecological processes of a manicured lawn to those of a forest or a meadow (termed 'non human-managed ecosystem' in the table) you will see some stark differences.

Manicured lawn
Non human-managed ecosystem
Nope.  Mowed grass does not flower.  No pollen= no food for pollinating insects. 
Yes. Most plants flower and their flowers produce pollen.  Pollen is food for animals and pollination is needed to produce the seeds for next year’s plants. 
Erosion control
Not really.  Unblocked water falls hard on a lawn and kicks up pieces of soil.  Water is then quickly shed from a lawn taking soil and nutrients with it.
Yes.  Plants slow the speed of falling water.  Once slowed it can percolate into the soil. 
Wildlife habitat
Not really.  There are no hiding places or food sources in a lawn.
Yes. Trees, shrubs, and herbs in a variety of heights and densities creates diverse habitat
Water filtration
Not really.  If water is shed it does not enter the soil where filtration happens.
Yes. Water enters the soil where soil microorganisms and plant roots clean it.

Pollution control
Nope.  Quick moving erosive water caries away excess fertilizer, acids from the rain, and household nasties (detergents, oils, cleaning supplies).
Yes.  Thick living soil can accept pollutants.  The living parts of the soil- roots, bacteria, fungus, and insects- can metabolize these pollutants and render them harmless.  
Oxygen production
Not really.  Lawns don’t contain much biomass (the amount of carbon).  Biomass is the direct product of respiration, where (in plants), carbon dioxide exchanged for gaseous oxygen.  Lawns don't make a lot of oxygen compared to a forest.
Yes.  Most non-managed systems contain more biomass than a lawn and therefor have produced wonderful, glorious, breathable oxygen.

This table could go on and on- obviously there are many ecological differences between our manicured lawns and non human-managed ecosystems.  Remembering that our backyards are the ecosystem we will see that the simple act of keeping a manicured lawn is preventing some pretty important ecological processes from occurring.      

So now what?  What can you do with your lawn?  What are the options?  Thankfully, gardeners, landscape designers, conservationists and permaculturalists across the country have begun to question the manicured lawn paradigm.  The goal is not to abandon backyard management, but instead, to manage our backyards in such a way that allows them to carry out ecological processes. The Mianus River Gorge Preserve in Westchester County has published this, which aids landowners in the conversion of their lawns into meadows.  For those of us don't have a large enough backyard to create a full blown meadow what are some other tools?  Ecosystem gardening is a neat way to incorporate ecological principals in your own backyard.  Also, the well known bird conservation group The Audubon Society has for a long time educated the public about backyard ecosystems.  On their website is this neat interactive drawing of a healthy lawn.  Alternatives to lawns differ from region to region, place to place, town to town.  Remember, the examples I have included in this paragraph are just jumping off points and they are meant to be modified to fit your backyard and your desires.  It is not necessary to have a backyard that looks like a jungle or a prairie- the goal of this post is to help landowners understand the natural processes occurring in their backyards and how they affect the organisms living there.  Simply cutting your grass less often would make a difference to the organisms that live in your backyard.     

What about unwanted organisms like ticks and poison ivy?  It is possible to choose an lawn alternative that protects you and your family from undesirable plants and animals. To avoid ticks, keep your recreation (gardening, game of catch) away from tick hot spots such as stone walls, leaf piles and dark, humid forest edges.  Also, by spreading a 3 foot mulch barrier between the nearby woodlot and your living/working area you can protect yourself from ticks.  

Mulch barrier: a landscaping tool to prevent ticks
The 100%, hands down, no foolin' best method to protect yourself from ticks is to check your body for them and be aware of your health.  Likewise, the best way to protect yourselves from poison ivy is to recognize and avoid it.  If desired, it can be removed from your backyard by hand (hands covered in gloves, that is).

Backyard management- to mow or not to mow? 

Thursday, March 22, 2012

Post #2 The trees in our backyards are animal nurseries

 Tate releasing a rehabilitated red tail hawk in Ohio

Once upon a time I rehabilitated injured raptors (wild eagles, owls, falcons, and hawks).  At the Glen Helen Raptor Center in Yellow Springs, Ohio roughly 150 injured raptors were brought to us each year and we assessed, cared for and (if appropriate) released the birds back into the wild.  In the wild world of raptor rehabilitation there are seasons you can predictably come to rely on, and these seasons reflect the rhythms of the natural world.  For example, we would only expect to see injured rough-legged hawks in the winter (in the summer they nest in the Arctic), fall and winter would bring us many juvenile birds out on their own for the first time, and our busiest season - spring - would bring us many injured babies.  Each spring we took in dozens of baby screech owls and kestrels, both of which nest in holes in trees.  How do baby raptors get injured?  1) They fall out of their nest or, 2) someone cuts down the tree they were nesting in.

As it turns out people do a lot of tree work during the nesting season- felling trees, limbing trees, pruning shrubs- which means there are lots of unhappy parents out there.  Nesting in trees is not unique to birds either- bats, raccoons, squirrels, opossums, hornets and sometimes porcupines all nest off the ground.  Once separated from the nest, young animals stand very little chance of surviving.  The guaranteed food source from mom and dad, warmth of the nest and the protection from predators vanishes instantly.  Could you imagine spending some quality time at home with the newborn when all of the sudden you start to feel your house rattle?  A loud tool with a smoking motor is slicing into your foundation and causing your house to slump.  Obviously devastating.  

Eastern screech owl in a tree cavity

A crow nest in a tree
To avoid cutting down a tree that contains a nest be aware what's living in your backyard.  Singing birds are a dead give away for an active nest.  Look for physical nests (usually made out of sticks) in trees and if you see tree a cavity, watch for animals coming and going.

Try to work around animal's nesting schedule.  Raptors usually next first, in late winter/early spring.  Songbirds start nesting in the early spring and continue through to mid summer.  Squirrels and bats nest in the spring.  To best avoid nesting critters, the fall is the best time to conduct tree work.      

If you do happen to cut down a tree which contains an animal nest you can call your local rehabilitator for instructions on how to help.  Just google 'wildlife rehabilitation' and your location and you will find a place.  Almost any bird will be taken in by a nearby rehabilitator. Mammals of greater conservation concern like bats (yes, bats are mammals) might be taken in.  Raccoons are not people's favorite so you might not find a lot of resources available for their rescue, but again, call your local rehabilitator.  See what they recently did for a squirrel.

As a result of habitat fragmentation (see post #1) our woodlots, backyards, town parks, old fields, and vacant lots are now the wild places for plants and animals to call home.  Like the baby screech owl that falls from its nests during our spring cleaning, our backyard management could mean a great deal to the critters that live there; sometimes the different between life and death.  


Friday, March 2, 2012

Post # 1. Where are we?

First post, let's start simple.  Where is Pound Ridge and how it fits into its larger landscape.  This can be answered in many ways- politically, socially, financially, aesthetically, ecologically, historically, geologically, physically, artistically, culinarily, etc., etc., etc., but because I like thinking about land use let's begin by considering the land use of the Eastern Seaboard, on which Pound Ridge, NY happily sits.

This video maps the densities of light pollution and human population along the Eastern Seaboard in 3-D, creating a rather bumpy surface. Consider any raised area on this map- this place has lights and people, (and therefore) houses, stores, roads, highways, buildings, ect.  These places are said to 'fragment' the landscape and leave the wild forests, meadows and wetlands that much smaller and less connected to one another.  Ecologists now have to ask themselves 'how do animal and plant populations (and their genes) move across a fragmented landscape?'      

This is a picture from space of the Northeast Megalopolis at night.  

This is Pound Ridge's backyard- we are part of this high density fragmented landscape.  Pound Ridge might appear only as a small bump in the video but we have to consider all of the map's mountains that surround us.  We can take a closer look at Pound Ridge (the pink balloon in picture) to see how the high density of the Eastern seaboard affects our local landscape.  We will start at the regional level and zoom into the town level:  

Region level.  The Hudson River is far left, Bridgeport, CT is far right.  
County level: highway 684 is visible on the left side.  

The squares in the picture are houses.  
The town of Pound Ridge.  A semi-fragmented landscape.

We can see that fragmentation happens at many scales; coastal, regional, sub-regional-town, watershed, etc.  What does this leave us with?  We find ourselves left with small bits and pieces of once continuous wild terrain.  Many big animals (big cats, bear, fisher) can't survive in a fragmented landscape like Pound Ridge, while others (gray squirrels and English sparrows) do quite well.  This shifting in animal abundances leaves ecologists and land managers wondering about animal-animal and animal-plant interactions of the future.  What about entire ecosystems?  How do they respond to fragmentation?  It is thought that fragmented ecosystems have reduced production of ecosystem services and biodiversity. 
It is futile to think that our ecosystems are like they were 100 years ago, therefore a growing emphasis is being put on our 'novel (or new) ecosystems' (see abstract here).  We are forced to engage nature in its current shape: chopped up, comprised of new animal and plant associations, invaded by plants from other continents, and possibly worst of all- an abstract notion almost totally removed from the thoughts, feelings and experience of most humans.  

Landowners have to recognize that the only wild places left in town may be their backyards.  We may not see our backyards as prime wildlife habitat, but in many cases it's all we've got left. To live lighter on the land we have to recognize how our actions at home and in our towns (planting trees, cutting down trees, mowing our lawns, etc.) affects the organisms that live there.