As arborists, we play a roll in ecosystem management. Arboriculture can be viewed from the perspective of resource management over several spatial scales, from considering the individual tree to larger landscape blocks of urban forest. To consider an individual tree’s role in the ecosystem is a complex endeavor, because of how dynamic the organizational hierachry of the larger urban forest is. Our cultural management practices also adds even further to the complexity of the matrix.

The book Ecosystem Management, edited by Mark S. Boyce and Alan Haney, has encouraged this discussion because of some of the topics I have come across early in the text, especially in Chapter 3: Concepts and Methods of Ecosystem Management: Lessons from Landscape Ecology by Thomas R Crow and Eric J. Gustafson. It reads, “How do we take fundamental information about ecological processes obtained at small scales, such as the physiological response of leaves to elevated levels of ozone, and apply it to a landscape, a region, or even a global scale?…the transfer of information from one level to another is not a simple additive process. Vital information from lower levels in a hierarchy may be extraneous information at higher levels of organization…A leaf, for example, is sensitive to changes in light conditions that can be measured in seconds and minutes. A forest stand integrates this information over weeks, months, and growing seasons, and its growth responses are measured in these time frames. At each level in the organizational hierarchy, new organizing principles apply and new properties emerge, so properties of simpler systems cannot effectively be predicted from the properties of simpler subsystems,” ( Boyce, Haney, 56).

This is an interesting idea in terms of what we see when we are monitoring trees and portions of the urban forest at large, and then trying to apply that to large-scale management theory. Singular trees in comparison to old growth forests or even larger patches of urban forest create very unique matrixes; one system does not translate to the next because of the common vocabulary term ‘tree’. But we tend to manage in general terms though more often than not. At industry specific think-tanks and conferences, we ask our colleagues what is working for them, what dosages are sufficient, what prices are working well, what’s the perfect set-up?

I can think of one case in particular that pertains to a conversation I had not long ago about the Hemlock Wooly Adelgid pest and how plummeting polar vortex temperatures are a wonderful abiotic factor in managing this invasive pest population. On a very small spatial scale, say the region in particular that is experiencing these cold temperatures, the pest could potentially be affected negatively. But this only applies in the context of that particular region and that particular pest and that particular generation of pest. At larger spatial scales, the declining pest population may not translate to other populations outside of the effects of the polar vortex. Smaller spatial scales in the landscape, and maybe even in pest management, are not simply microcosms of larger spatial scales. So then, even managing the exact same pests can be very different from one region or one landscape to the next. Rules of thumb in terms of management should be defined within their spatial scale, and within time and space.

Which leads me to my next point-highlighted by another section of Ecosystem Management-of the importance of how context affects content. The text reads, “ecosystems are not closed, self-supporting systems, but rather parts of larger interacting systems. Serious problems can arise from treating each ecosystem as an isolated entity without regard for the context created by the broader landscape matrix, “(Boyce, Haney, 57).

I often wonder how important an individual tree may be in the context of the particular property where I work. This consideration is still narrow minded in the sense that I’m still thinking about the content (individual tree) in a rather small context (individual property). In ecosystem management terms, this is a very small spatial scale. In reality, the affects of that tree could be very large and very complex in ways that I may never understand. This consideration is not to discourage the prospect of arboriculture as it applies on small scales, but to think of content in different contexts-to actually broaden the prospect for arboriculture and its place in ecosystem management. Our management mantras or credos can have immense affects on the greater urban forest at large, but quite possibly in ways we can not define. How do our decisions on managing individual trees affect the larger landscape ecology; the “tens to hundreds of square kilometers in which mosaics of ecosystems are considered collectively and interactively,” (Boyce, Haney 56). I often think like a clinician in the sense of wanting my clients to feel better or for their trees to get better, as an arborist I want to diagnose properly and ease any pain as best I can (Stephan Zimmerman, Limbwalker). There must be something I can do. But am I a steward of the populace, or of the environment, or of the ecosystem, or of ecology? I feel like I am drifting into questions about ethics, but so be it. Maybe it’s a question of accountability. As arborists, what can we potentially be accountable for?

Chapter 3 of Ecosystem Management also reminds us that, “most critical environmental issues are broad-scale problems. Witness concerns about global warming, ozone depletion in the upper atmosphere, deforestation in the tropics, global loss of biological diversity, lost-distance transport and dispersion of toxins, and regional forest decline caused by interactions of drought, pathogens and pollution,” (Boyce, Haney, 55). When we become transfixed in our small spatial scales of individual trees and individual clients and contracts, our content and our context can dangerously shift from solving problems to endlessly treating symptoms. A polar vortex may kill a few generations of wooly adelgid, but does it halt global trade? These are vague and broad questions to consider.

I am intrigued by the idea of arboriculture in the context of ecosystem management theories and certainly want to pursue this inspiration further.