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Tuesday, July 16, 2013

Managing Land for Ecological Diversity

         According to the Penn State Center for Private Forests, there are some 750,000 owners of forest lands in Pennsylvania.  For those that manage their woodlots to support ongoing timber harvesting, there are a number of resources to guide them toward sustainable practices.  See, for example, Forest Stuardship Principles for Landowners and Forest Stewardship: Best Management Practices for Pennsylvania Forests.  However, only some 15% of these 750,000 landowners timber their holdings.  What about the other 85%?  What do they do with their woodlands?

Some, we speculate, don't do anything with their parcels and just leave them alone.  Others use them for recreation and aesthetic pleasure.  Others to provide privacy.  Some for financial investment.  And some to provide habitat for wildlife and/or to promote ecological diversity.  (More research is needed to pin down the proportions of this number as well as their different motivations, goals, and constraints.)

For the 85% who don't timber, what resources are available to guide them, especially those who wish to emphasize ecological principles on their lands? 

Many of the documents written for specialized practices also include information potentially useful for the ecologically intent landowner, as well. For example. in the discussion of best management practices referenced above, a number of suggestions are included for maintaining forest sustainability (e.g., preserving robust seed-bearing trees, controlling the canopy, protecting seedlings) and for mitigating the damage done by timbering operations on the overall ecology (e.g., preserving vernal pools and other sensitive areas, not compacting the soil unnecessarily,  and protecting water and soil quality).  But, as would be expected in a discussion of sustainable forestry, priority is given to full-size trees, especially those valuable as timber.  Preservation of woody or herbaceous plants, of shrubs, and of mid-canopy trees is secondary; and wildlife is often viewed as a factor to be controlled.

Other possible sources of information for the ecologically intent can be found in publications aimed at improving wildlife habitat, especially for game species.  For example, there is currently a concerted effort to re-establish habitat for the American Woodcock.  A number of publications describe beneficial practices, trace progress-to-date, and promote these efforts. Woodcock require different terrain for courtship, feeding, nesting, and roosting.  These include clearings, grasslands, shrublands, and new-growth areas such as alder and aspen stands.  These varied conditions are often beneficial to other species of birds such as the Golden Winged Warbler as well as a number of herbaceous plant species.  Thus, developing a site to promote a particular species of wildlife can extend the ecological diversity of a location; however, the particular requirements of that species will likely skew the ecology toward their particular needs as opposed to a more balanced overall ecology.

What is needed is a set of principles and a set of practices that can extend the ecological diversity of an area in a way that is consistent with both the underlying physical characteristics of the location and the desires and goals of the landowner. This approach would not replace guidelines such as those for sustainable forest management or developing wildlife habitat nor would it imply any criticism of those approaches.  Rather, it would complement them by offering an alternative for those landowners who wish to focus on ecological diversity. The discussion below includes five tasks that could provide a start in this direction.

1. Catalog plants

Identify the plants present on the site.  For easy reference, you may wish to create a list, a spreadsheet, or a database of them. Since these plants are already on the site, they provide a ready reference to those that are likely to survive in the current conditions.  Consequently, the landowner can increase their numbers to achieve various goals, such as increasing wildlife habitat or providing visual screening, with a degree of confidence.  When cataloging plants, note those that are generally regarded as native, since they are likely to be less invasive than introduced species, better suited to the local environment, and require less maintenance.

2. Identify plant communities

Plants in nature do not occur in isolation but in relations to one-another, to underlying conditions, and to wildlife.  An interconnected group of plants is often referred to as a plant community. Jean Fike provides a useful definition: "A plant community is an assemblage of plant populations sharing a common environment and interacting with each other, with animal populations, and with the physical environment." (Jean Fike, Terrestrial and Palustrine Plant Communities of Pennsylvania, 1999.)
A first step for identifying a plant community -- and offering a useful perspective in and of itself -- is to identify the underlying physical conditions of the site.  Important factors include the following:
  • geographic location (latitude and longitude)
  • elevation
  • topography
  • light
  • soil
  • hydrology
  • disturbance
These factors, along with the soil seed bank, strongly influence the plants that will be present and, hence, the resulting plant community.
To identify the actual communities present on a site, you need to take into account both underlying environmental factors and the actual plants growing there.  Fike discusses some 105 communities found in Pennsylvania.  Hers is a good reference with which to begin.  A second edition, by Zimmerman, et. al., is also available.  It updates the Palustrine portions of Fike and includes additional materials concerned with ecology, conservation, and management.  Identifying your particular communities can be done by matching the conditions and plants listed in these references with those that you have observed and cataloged.

3. Create a vision and a set of goals

A vision is a description of what you would like the site to become.  Goals are intermediate steps between the site as it currently exists and the site envisioned.  Thus, the goals constitute a kind of action plan.
A vision can be completely passive, involve an ambitious plan of execution, or anything in between.  At one extreme, with a more detailed understanding of the plants present on the land and the environmental conditions in which they live, simply watching them evolve over time can be quite interesting.  On the other hand, you may wish to actively intervene in certain areas.  For  example, if the plot is an old farm, you may wish to do a prairie restoration on some fields by planting warm season grasses or you may wish to restore a forest in a cleared area by doing a hardwood planting. Assuming, of course, that the underlying environmental conditions support these plant communities. You may wish to refine and/or extend an existing plant community, such as a marsh or vernal pool.  This could be done by clearing invasives or plants inconsistent with the community and by supplement those present with desirable additions consistent with the community.  One could even "swap" one community for another if the conditions are conducive to both.  Finally, a plan could involve certain construction tasks to provide access, barriers, features of interest, etc.
Don't worry about getting your vision completely "right;"  it can, and likely will, evolve as you become more familiar with the site.  As you make changes, new ideas are sure to emerge. 

4. Identify plants to be added or removed

Once you have a vision for your land, buttressed by a catalog of the plants growing on it and an awareness of its underlying physical attributes, a next step is to identify any plants you would like to add or remove. Let's start with removing plants.
You may wish to remove plants for any number of reasons.  For example, you may wish to remove a particular tree because it is diseased or injured, or a whole collection of trees to open up a view.  You may decide  to remove a particular species because you just don't like that plant.  But, by far, the most important reason for removing plants is to control invasives.  These are species that are likely to overrun and force out other desirable species, if left alone.  In central Pennsylvania, some invasives that must be controlled include Autumn Olive, Tartarian Honeysuckle, Multiflora Rose, Purple Loosestrife, and Japanese Knotweed.  Also threatening under some conditions are Bittersweet, Goldenrod, and Black Walnut.  For a comprehensive list, see the DCNR Invasive Plants list.  If you have any of these plants -- and you likely will -- you must reconcile yourself to ongoing vigilance and maintenance or suffer the consequences.  DCNR provides several helpful publications pertaining to controlling invasives.
Adding species is a lot more interesting than removing them!  Again, there are several reasons you may wish to do so.  You may wish to add a plant type that you don't have simply because you like it or it serves some landscaping purpose.  If you do, be sure that it is compatible with the conditions and plant community where you want to plant it.  You may wish to add one or more species to extend an existing plant community, thereby extending the ecological diversity of your property. Under some conditions, you may wish to "swap" one plant community for another, assuming the new one is compatible with the underlying environmental conditions of the location.  However, this is an extreme undertaking and, given the inherent power of the soil seed bank, probably one best avoided.

5. Develop plans for management, control, and financial support

What will happen to your land beyond your lifetime or your capability to manage it?  These are uncomfortable questions, but ones that should be faced, perhaps sooner than later.  Again, one option is to do nothing.  If your land has been managed for ecological diversity for some period of time, along with similar parcels by other landowners, collectively they will have contributed to the overall ecological health of your area.  Over time, the addition and subtraction of individual tracts to this collective should produce at least some benefits to the environment.  But, how much better it would be if individual tracts could be sustained indefinitely!  For this to happen, your tract is likely to need some type of perpetuating management and control structure as well as on-going financial resources.
Perhaps the simplest management and control structure is to be sure that the heirs to the property (e.g., your children) share your vision and goals and are willing to put the time and effort into carrying them forward.  But there is, of course, no guarantee they will follow through.  Adding a conservation easement can help to ensure that your primary objectives are continued, but even easements are not 100% certain.  An alternative is to assign actual ownership to some continuing entity such as a corporation or trust set up to maintain the property.  This is a complex process and will require serious negotiations among the interested parties.
Last but not least is the question of how the property will be supported financially beyond your lifetime.  A hard fact of reality is that maintaining a property with the intent of extending its ecological diversity is not likely to be financially neutral.  It probably has few, if any, ways of generating a cash-flow.  Perhaps you have been fortunate enough to receive grants or incentives to establish the ecological basis for the site, but such payments can't be counted on, especially if someone else will have to draft the proposals and manage any funded projects that result.  Moneys from admissions or fees are likely to be inadequate and, ironically, if public access could generate substantial resources, incursion by such numbers would likely be counter-productive ecologically.  You  may be able to identify an on-going organization, such as The Nature Conservancy, who could take ownership, but even they may not maintain the property in accord with your wishes.  One other possibility is to establish some type of financial trust or endowment with resources sufficient to maintain the property in perpetuity.  Not every landowner will have or wish to assign such resources, but for those that do, this option may be the most promising at the current time.


Why would a landowner devote a tract of land to ecological diversity? Whereas this may result in healthy soil and water, abundant plant and animal life, and a landscape with an attractive natural look, doing so is unlikely to maximize financial return. The reason is more likely to be personal. Doing so will almost certainly enable a broader as well as more detailed understanding of the land.  He or she will know more about the varied plants and animals living there, the underlying conditions that affect them, and the relations among them.  The landowner will see more and be more aware.  For better or worse, this is likely to lead to a more intimate relation between landowner and land, perhaps including affection for it.  I am reminded of Aldo Leopold's notion of a land ethic. Leopold believed that we live in an expanded community that includes not just other people but also soils, waters, plants, and animals, which he called the land. Implicit in this view is that we should cooperate with each other for the mutual benefit of all. By placing land stewardship in an ethical context, Leopold provides a means for us to decide what we should or should not do and for deciding what is important. Having an ethical and philosophical foundation for one's actions is reassuring, but such deep considerations will not be necessary or desirable for all landowners.  Perhaps, in the end, it may be sufficient that managing land for ecological diversity just seems like a good thing to do, the right thing to do.

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