Responses of Wildlife to Clearcutting and Associated Treatments in the Eastern United States

Black and white diagram illustrating cleracutting and wildlife

Department of Forest Resources
Clemson University

June 1997

credits and acknowledgements

 

Technical Paper No. 19
Posted March, 2000


Clearcutting is a controversial forest management practice. Controversy regarding clearcutting on public lands in the eastern United States began on National Forests in the mountains of West Virginia and North Carolina during the 1960's (Borelli 1972). Large cuts of 400 acres or more, some located on steep slopes and adjacent to highways, evoked instant criticism. Prompted by critics of the practice, the attitude developed that if it looks bad, it must be bad. The temporary absence of merchantable trees after cutting, the presence of logging slash, and soil disturbance made clearcuts seem uglier than areas harvested by other cutting methods (Lang 1975). Indeed, over the years, clearcutting’s unsightly appearance caused a general lack of public acceptance (Marquis 1972).

Photo of clearcutting

photo after one year of clearcutting

What the public fails to appreciate is that many wildlife species evolved in forests frequently disturbed naturally by fire, violent weather, and attacks by diseases and insects. The removal of the forest canopy by clearcutting allows sunlight to reach the forest floor, which in turn dramatically improves conditions favorable to the establishment of grasses, forbs, and shrubs (essential components of the habitat of many species) and those tree species (often some of the most valuable) that are intolerant of shade (Marquis 1972, Soc. of Am. For. 1981). Nevertheless, environmental activists (e.g., Wood 1971, Fritz 1983, Bourne 1986) have fanned the fires of controversy; as a result, clearcutting is considered by the general public to be disastrous to forest resources (Patric and Schell 1990).

Clearcutting is controversial in other parts of the world as well. In centuries past, on the steep mountains of Europe and more recently in mountainous parts of Thailand, laws were enacted banning clearcutting. In contrast, some countries in Europe, such as Sweden, have experienced problems with uneven-aged management and now require by law that most forests be harvested by clearcutting (Kimmins 1992). This European experience is similar to that of national forests of the eastern United States from about 1920 until about 1960, when high quality trees were selectively harvested under the guise of selection silviculture. Selective cutting eventually evolved into "high grading," a practice that accelerated the succession of less valuable, shade-tolerant species.

Forests in the eastern United States are particularly resilient to disturbance (Waide and Swank 1976, Sharitz et al. 1992, Van Lear 1992) and unless they are converted to agriculture, housing developments or other uses, harvested areas regenerate quickly. Unless there is further disturbance or management intervention, they usually return naturally through ecological succession to species mixtures similar to those of the preharvest forest. In fact, most current forest stands in the eastern United States coveted for their "naturalness" actually are the direct result of clearcutting or other heavy cutting which occurred during the late 19th or early 20th century (USDA Forest Service 1988, MacCleery 1991a, MacCleery 1991b). Even large portions of Great Smoky Mountains National Park, an area that many consider to be among the most natural in the East, were heavily cut in the early 1900's (USDI 1990).

Sometimes clearcutting is justly criticized where it has been inappropriately applied. Its use on fragile, steep mountain slopes may cause heavy soil erosion and land slides. However, in such cases roads into the logging area are generally more responsible for erosion problems than the practice of clearcutting per se (Brown and Krygier 1971). Clearcuts that have been cable logged in the Southern Appalachians seldom experience such problems. In fact, even-aged management using clearcutting generally results in less road mileage and fewer entries for harvesting activities than uneven-aged management systems, thereby causing less erosion and stream sedimentation in the long-run (Van Lear 1992).

Clearcutting also has been blamed for the decline of the longleaf pine ecosystem (Noss 1989). However, fire suppression and conversion of longleaf pine forests to agriculture, urban expansion, and to faster growing, more easily regenerated loblolly and slash pine have contributed much more importantly than clearcutting, per se, to the 97% decline in the area occupied by longleaf in the Southeast (Kelly and Bechtold 1990, Frost 1993). Without this intervention, many clearcut sites would have regenerated naturally to longleaf (Boyer 1990, Landers et al. 1995).

Pressures from human population growth drive most forest conversion activities in the United States and, in fact, throughout the world. By the year 2030, it is estimated that the population of the United States will reach 300 million; and the South, alone, will need another 18 million acres for urban expansion (Healy 1985). Accompanying such growth will be additional increases in commercial and agricultural uses of land. With this expected increase in population will also come an increase in demand for wood products, requiring more intensive management of the remaining forest. Thus, the need for effective, economical ways of producing wood, such as clearcutting, also will likely increase in the future.

The clearcutting controversy is not confined to its relationship to economics or human perceptions of beauty; the controversy extends to environmental concerns as well. In this report, we examine published scientific literature regarding the effects of clearcutting on wildlife populations and their habitat in the eastern United States. We begin by reviewing studies about effects of clearcutting on selected wildlife species and groups of related species. Then, having learned from these studies some of the behavioral and habitat adaptations of these animals, we can better interpret some purely botanical studies of clearcutting and suggest how the wildlife which inhabits such sites probably reacted. Finally, we summarize these studies and make suggestions for improved management.

With two exceptions, all studies of wildlife cited in this paper were conducted in the Humid Temperate Domain, which is the largest ecological unit in an ecosystem classification developed by Bailey et al. (1994) and described by Davis (1994). This unit includes that area from the extreme eastern portions of North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, and Texas to the Atlantic Coast. A major portion of the research studies referred to in the text were previously summarized in Harlow and Van Lear (1981; 1987) and Sweeney et al. (1993). Most of the data on amphibians was taken from deMaynadier and Hunter (1995). More than 80% of the 233 research reports regarding even-aged management and wildlife were published during the 1980s and 1990s. Twenty-six percent concerned songbirds and 21% concerned white-tailed deer (Table 1). Major sources included 24 different “mainstream” scientific journals and the publications of 5 United States Government agencies, 28 state universities, and 10 privately operated natural resource companies (Table 2).

Table 1.  Published reports cited regarding the effects of clearcutting on wildlife, by species and years in the eastern United States

Years

White-
Tailed Deer

Moose

Game Birds

Hares & Rabbits

Tree Squirrels

Black Bear, Marten,
Cougar, & Lynx

Nongame Small Mammals

Birds

Amphibians & Reptiles

Totals

1950-59

1

---

1

---

1

---

1

---

---

4

1960-69

9

---

3

---

1

1

---

---

---

14

1970-79

11

1

4

2

2

2

4

4

1

31

1980-89

20

1

12

7

5

11

13

22

11

102

1990-96

8

2

6

2

4

4

7

32

13

78

1997

---

---

---

---

---

---

---

3

1

4

totals

49

4

26

11

13

18

25

61

26

233


Table 2.  Major Sources of information used in developing this report.

Sources of Information

Number of Sources

Number of Articles & Technical Reports

Scientific Journals 24 126

U.S. Government Agencies

5

36

State Resources Agencies and Universities

28

54

Private Outlets

10

17

Totals

67

233

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