• Ben Knapp

Silviculture...what is the state of the field?

I have an undergraduate degree in forestry and two post-baccalaureate degrees focusing on silviculture. I teach several silviculture courses and consider it the main area of my research. I love my job, working with students and land managers, researching questions about forest ecology that can be applied to practical problems. I see silviculture as a wide-open field right now, greatly needed in a time of intensified uncertainty regarding the management of terrestrial ecosystems and providing a critical link between science and on-the-ground implementation.

Despite my enthusiasm for it, I think silviculture has an image problem. I don't think that this is a new phenomena, but over the past several years it has been demonstrated to me in many different ways and gotten me thinking about the implications for the future of the field.

I often start my introductory silviculture course by surveying the students to see what they know coming into the class. Students commonly define silviculture as something in the ballpark of 'growing trees', which is logical and not entirely wrong. Some push the definition towards trying to maximize timber production, which is a much more limited view. Recently, a new graduate student entering our program expressed disinterest in silviculture because it was 'cutting down a forest' (to paraphrase). This perception of the field is disheartening, missing the point at best, but unfortunately appears to be common in some basic form.

So what is silviculture? As an applied field, it is dynamic - changing objectives of its focus with changing viewpoints of society. In a fundamental sense, it encompasses the practices and approaches we use to manage forested ecosystems. There is a persistent perception that silviculture is all about timber production (and perhaps even maximization of production at the expense of any other objective). This idea is founded in the development of the field, originally formulated with a primary focus on sustainable yield of forest products. The legacy of this initial timber focus can be seen in some of the core concepts and techniques used in silviculture, although applications today extend to a complex suite of objectives across a range of land ownerships, interests, uses, and values. In short, silviculture integrates forest ecology into management action to best meet objectives in a sustainable way.

Recently, there have been some interesting discussion articles that highlight the contemporary state of silviculture. For example, D'Amato and co-authors (2018)

describe changes to the field over the past 30 year period, noting the importance of changing land ownership, technologies, and management objectives in defining current silvicultural problems and approaches. The ecological challenges facing sustainable forest management are complex and varied, inclusive of climate change, interaction with invasive species, threats and effects of wildland fire, etc.. Consequently, silvicultural research draws on expertise across biological and physical sciences, often focusing on certain elements that contribute to a larger problem or question. So the research may explore aspects of physiology, or invasive species ecology, or fire science, or pathogen spread, or seed biology and dispersal, or soil chemistry, or many other topics that drive patterns in forest ecosystems. As noted by Jain and co-authors (2019)
, the skillset of the silviculturist is broad, but a critical element is the linkage between the scientific understanding and the application to management. And it certainly could be argued that a strength to the field is a pragmatic and operational approach to the application of ecological understanding.

I attended a forest ecology conference a few weeks ago and overheard a conversation about savanna restoration, in which one of the individuals commented to the effect that restoration efforts were misunderstood by the 'silviculture types' (again a paraphrase). I am interested in restoration ecology and much of the research I conduct is related to restoration objectives. I see many parallels between restoration ecology and silviculture. Both are intrinsically applied fields. Both require defined objectives for management (an endpoint condition), must evaluate the current conditions (the starting point), and determine appropriate practices for getting from the starting point to the endpoint. Restoration objectives do not need to maximize timber production, and in some case do not assess timber value at all. Restoration objectives are among the objectives that contemporary silviculture encompasses, and the 'silviculture types' should be able to provide useful perspective in restoration scenarios. As an example, silviculture places emphasis on understanding how ecosystems change through time (forest stand dynamics), and understanding that the endpoint condition for any restoration or management objective will not stay constant through time is a critical concept in developing sustainable management plans.

Effects of the current perceptions of silviculture may turn into a long-term pipeline problem for the field. I have noticed fewer applications received for graduate research positions I post if explicitly focused on silviculture, sometimes having to repost positions multiple times. I often raise this concern with colleagues at conferences and seem to not be alone. As the old generation comes into retirement in academia and federal scientist positions, there have been and will continue to be new opportunities for young silviculturists. I see the critical importance of continuing to usher through excellent students passionate about the field, and I feel blessed for the opportunity to work with the wonderful students in my lab.

Despite the expressed concerns, it is an exciting time to be a silviculturist. The breadth of the field gives great opportunity to develop and follow research questions of interest, and they abound. The impact from the application of those findings offers immense satisfaction in making a difference in ecosystem stewardship. We need advocates to communicate the good work being done by the many talented students, scientists, and practitioners, changing the perception of silviculture to one in which the scope of the field is better understood.

Old-growth longleaf pine managed with the Stoddard-Neel system