A common theme among some discussions here seems to be a discrepancy as to what constitutes the 'environmental impacts' of climbing. There are also few real studies brought forward. I thought I'd do a bit of a literature search on the topic for those interested.
(Full disclosure - I'm finishing a phd in forest ecology at UW and currently working as an ecologist for Parks Canada; I like both trad and sport climbing and have doing both for about 12 years.)
A typical first area of focus for environmental impact analysis is to look at ecological effects of a management activity. A few recent studies show some regional variations (ecology is indeed a science of place; what holds true in one system will not necessarily hold true in another, although common themes can often be found in similar ecosystems).
The following article was published in the journal Conservation Biology in 1998, setting off considerable interest:
Effects of Rock Climbing on Cliff Plant Communities at Joshua Tree National Park, California
Richard J. Camp and Richard L. Knight
Conservation Biology 12: 1302-06, 1998
Abstract: We compared the plant communities on cliffs used for rock climbing with cliffs not used for climbing. Eighteen cliffs in Joshua Tree National Park, California (six each with no climbing, moderate climbing, and intensive climbing) were sampled for plant diversity and community structure. Plants were sampled on cliff faces and at the base of cliffs. The dominant taxa were Quercus cornelius-mulleri, Ericameria cuneata var. cuneata, and Bromus madritensis ssp. rubens. Plant species richness on cliff faces and at the base of cliffs was greater for cliffs with no evidence of climbing and lowest for cliffs with intensive use. Numbers of individual plants decreased with increased climbing use. Trees, shrubs, forbs, and cacti had greater relative abundances on cliffs without climbing than on cliffs with climbing. Plant cover on cliff faces decreased with increased climbing use. Adaptive management will be necessary to minimize the deleterious effects of rock climbing on plant communities associated with cliffs.
Results were reported in the highly respected magazine/journal Science:
Researchers venturing onto remote bluffs find them to be oases of diversity, but rock climbers are taking out species even as scientists discover them
By Kevin Krajick, Science 283: 1623-25
They're vertical, they're made of rock, and you can't see them up close without risking your neck. So it's not surprising that few biologists have paid much attention to cliffs. But lately, some hardy researchers have dangled from ropes alongside high bluffs, and they are finding unusual and ancient communities that don't exist in the flatlands below.
These first forays have turned up surprisingly diverse communities, including rare plants and lichens, birds, and trees nearly 1000 years old. "Cliffs protect themselves very well by being so inaccessible, so they can have unusual communities even in heavily populated areas," says Jerry Freilich, former ecologist for California's Joshua Tree National Park. Joshua Tree and other parks are commissioning new studies on these hard-to-reach habitats, largely because a boom in rock climbing is putting unprecedented pressure on them, says Freilich, now science director for the Nature Conservancy of Wyoming.
Wildlife biologists have long known that raptors such as peregrine falcons and red-tailed hawks nest on cliffs, where predators can't get at their young. And a few researchers cataloged sea-cliff plants in Ireland and Britain in the 1980s. But until fairly recently, there have been no studies of cliffs as distinct ecosystems. "Look at how hostile they appear. No one really viewed them as habitat," says Richard Knight, a professor of wildlife biology at Colorado State University in Fort Collins.
Knight and graduate student Richard Camp recently discovered that some of Joshua Tree's granite spires are actually islandlike centers of diversity. They found 60% more bird species, and three times as many plant species, on the cliffs than were on the flat, arid desert floors below. From top to bottom, the cliffs provide all sorts of niches: Rock wrens and white-throated swifts rush in and out of cracks where they nest in great chirping masses, while the prairie falcons that prey on them incubate eggs on nearby ledges. Rock faces concentrate infrequent rains, dribbling moisture down to ledges and cliff bases to supply trees and succulents such as quercus oak and staghorn cactus that won't grow elsewhere; Lazuli buntings and other Neotropical migrant birds use this vegetation for nesting and food.
Researchers are still figuring out what makes some of these rocky, windswept sites so rich. One reason is that cliffs create a classic "edge effect"--a break in the normal landscape that is often more diverse than, say, the monotonous interior of a forest. Winds that bring insects and seeds from all over may also play a role. For whatever reason, "we do know the Joshua Tree cliffs are a distinct place," says Knight.
And because cliffs are so inaccessible, organisms once widespread may end up clinging to them as sanctuaries. About 5 years ago, in a boat off the Hawaiian island of Kaui, biologists from the National Tropical Botanical Garden there spotted what they believe were the last surviving individuals of Munroidendron racemosum, a primitive-looking tree with long, pendulous branches. The trees were sprouting from volcanic cliff ledges that looked as if they were about to crumble into the sea. All the others of their kind, once common on the island, had been eaten by human-introduced goats that couldn't reach this one last refuge. The biologists rappelled down, rescued seeds, and have since repropagated the species, says Paul Cox, director of the botanical garden.
Cliffs in the midwestern and southern United States also are home to a host of endangered species that have either been pushed there or just prefer rocky spots. They include such plants as mud warts and water hyssops, which grow in shallow seasonal pools that form in cliff rocks in Minnesota, and lichens such as Parmelia stictica, which cling to vertical faces.
Lichens are often a major component of cliff ecosystems, notes biologist Michael Farris of Hamline University in St. Paul, Minnesota, but these low-profile organisms are hard to identify and poorly known. So lichen biology remains a wide-open field. Last summer, rock climber Peter Smith, then a master's student in biology at Appalachian State University in Boone, North Carolina, surveyed one small part of the walls of nearby Linville Gorge and quickly came up with 23 genera inhabiting several distinct zones according to moisture. He also spotted one entirely new species, since named Fuscidea pallida. "He only did 12 transects, which makes us think there are many more undiscovered things up there," says Gary Walker, Smith's adviser.
In addition to their diversity, parts of cliff ecosystems can be remarkably ancient. Botanist Doug Larson and dendrochronologist Peter Kelly of the University of Guelph in Ontario, Canada, have found that some of the eastern white cedars dominating the 800-kilometer-long Niagara Escarpment of the Great Lakes region are up to 800 years old; well-preserved dead trees are more than twice that age.
Many of the cedars have multiple root systems attached directly to soil-less solution hollows and cracks in bare rock. Larson and his colleagues have found dense colonies of algae, bacteria, and fungi penetrating 1 to 3 millimeters into these apparently solid rocks. Larson hypothesizes that these so-called cryptoendoliths--previously known mainly from Antarctica--may help nourish the trees. Larson also notes that the cedars are apparently adapted to slow growth rates; in fact they are among the slowest growing plants known, adding only a couple of layers of cells each year, compared to perhaps 600 layers for their cousins on flat land. Twisted trunks may reach 3 feet in diameter, but some 200-year-old specimens are no bigger than a toilet plunger. Larson believes slow growth assures longevity and thus survival of the species. "It's an advantage--if they grew fast, gravity would drag them off before they got a chance to reproduce," he says.
Unfortunately, scientists are not the only ones discovering cliffs. Last year, 4 million people went rock climbing in the United States alone, and they left their mark on these fragile ecosystems, as Knight and Camp report in studies in the December 1998 issue of Conservation Biology and the April issue of the Wildlife Society Bulletin. Some Joshua Tree prominences are now hung with so many ropes that they look like Gulliver tied down by Lilliputians. To keep regular routes safe, climbers routinely "garden" them, pulling plants and soil out of cracks and wire-brushing lichens off protruding handholds.
Not surprisingly, Knight and Camp's studies show that climbers reduce plant cover and drive off birds. Independent botany consultant Victoria Nuzzo of Rockford, Illinois, showed that climbers reduced lichen cover and species by half and took out three-quarters of threatened cliff goldenrod plants at one site in northern Illinois's Mississippi Palisades State Park. Perhaps worst of all, climbers on the Niagara Escarpment are clearing the way by cutting down the old trees. Survivors may be used to fasten ropes, which strips their bark. Dendrochronologist Kelly has meticulously documented the damage; he dated one tree that germinated in 1215--and had its main axis sawed off in 1992.
Because the recognition of cliff life is so new, few parks have gotten around to making rules. As studies build, that may change. "I like to think that the more we learn about these places, the more we can demonstrate how special they are," says Kelly.
This prompted the following responses, both published in Science:
Climbing and Cliff Ecology
We are writing on behalf of the Access Fund (a climber's conservation and advocacy organization) to express concern regarding Kevin Krajick's article "Scientists--and climbers--discover cliff ecosystems" (News Focus, 12 Mar., p. 1623). We feel that Krajick presented only one side of the story with regard to climbing and cliff ecology. For example, Krajick points out that "the recognition of cliff life is so new, few parks have gotten around to making rules."
However, he does not mention that where "rules" such as access restrictions for climbing have been established to protect sensitive cliff-dwelling species, and where these are coupled with education and outreach, there is widespread compliance by climbers. For example, the Access Fund has details of ecologically based climbing restrictions at 94 locations, some of which have been in effect for more than two decades. Most are enforced on public lands, and all were established through the cooperation of climbers and land managers.
Furthermore, while there have been few published studies that have directly measured the impact of climbing on cliff systems (1), rock-climbers themselves, through their support of the Access Fund, have contributed financial support toward this field of research for the past 10 years. This includes the studies by Nuzzo (2) and four new partnership projects in 1999. In addition, the Access Fund is often acknowledged in other published work for providing advice and support. Unfortunately, these commitments to cooperation and to the advancement of our understanding of cliff systems are not well reflected in Krajick's article.
As scientists continue to explore cliff systems and as this information is passed along to land managers, the climbing community should be involved at each step so that appropriate education, resource protection, and recreational use can be established. We encourage interested parties to contact the Access Fund for information about climbing-related management plans or the possibility of small-dollar grants to support cliff-related research.
The Access Fund,
P.O. Box 17010,
Boulder, CO 80308, USA
Having climbed more than 35 years, and twice in Joshua Tree Park, I would like to point out that cliff-climbing routes are generally restricted to very narrow vertical paths because they follow faults and cracks that provide hand- and footholds. Generally, less than 1 percent of the rocks are actually trod on. This would not lead to climbers "taking out" an entire species.
Congressional acts that created parks emphasized use and conservation for future users, which has resulted in many more citizens who appreciate wilderness and who promote conservation. Trying to lock up the wilderness--or the top of a pinnacle at Joshua Tree--for ideological reasons is shortsighted, not to mention unfair to users.
Warren G. Guntheroth
Department of Pediatrics,
University of Washington School of Medicine,
Seattle, WA 98195, USA
Studies in other areas have also been done. The following caught my eye, from a search in Web of Science:
Structure of cliff vegetation on exposed cliffs and the effect of rock climbing
Author(s): Nuzzo VA
CANADIAN JOURNAL OF BOTANY 74 (4): 607-617 APR 1996
Abstract: Vegetational structure of exposed dolomitic cliffs in the driftless region of northwest Illinois was quantified from 186 quadrats on five cliffs. All cliffs were sparsely vegetated, with a total of 41 species (14 lichen and 27 vascular) recorded in the upper 6 m. On all cliffs, cover averaged 16.03%, with lichen contributing 10.23% cover and vascular vegetation 5.80% cover. Seventy percent of all vegetation grew within 3 m of the cliff top. Linear regression indicated that both cover and density of vascular, but not lichen, flora increased with increased fracturing and decreased with distance from the cliff top. TWINSPAN arranged the quadrats into five groups that differed in lichen and vascular cover and a sixth group that consisted of bare rock. Spatial distribution of the community groups occurred at a small scale, influenced by small scale differences in rock fracturing, slope, weathering, and likely moisture availability. Climbing significantly reduced lichen cover and lichen species density by 50%, from 13.7% cover and 2.4 species/0.25 m(2) on unclimbed cliffs, to 6.7% cover and 1.2 species/0.25 m(2) on climbed cliffs. Climbing did not have an apparent effect on vascular vegetation, which ranged from 2.74 to 10.62% cover on individual cliffs. Total plant cover averaged 19.7% on three unclimbed cliffs and 12.3% on two climbed cliffs, because of the impact on lichen cover. Although climbed cliffs had lower lichen cover, distribution of TWINSPAN-defined community groups was similar on both climbed and unclimbed cliffs, indicating that environmental and physical variables were the primary determinants of cliff flora on these vertical exposed cliffs.
The effects of rock climbing on the vegetation of three Minnesota cliff systems
CANADIAN JOURNAL OF BOTANY 76 (12): 1981-1990 DEC 1998
Abstract: I quantified the distribution and abundance of major plant taxa on three distinct cliff systems in Minnesota and examined the effects of recreational rock climbing on that vegetation. The three cliff systems differed significantly in the amount and type of vegetation present in undisturbed plots. Frequencies of most taxa were lower in climbed areas, although the differences were generally not significant. Total plant cover was significantly lower in climbed plots at all three locations. Fragile forms, such as umbilicate and fruticose lichens, were especially sensitive to human disturbance. The microtopography of the rock substrate had a significant impact on both the amount of vegetation present and the use of a cliff area by climbers. Cracks in the rock were significantly more common in climbed areas while ledges were less common. Microtopography also varied with the technical difficulty of the climbing route. While human impact decreased vegetation frequency and cover on these cliffs, identification of causal links between human disturbance and vegetation structure must include a careful assessment of the geological and environmental factors that strongly influence both human use and vegetation dynamics.
EFFECTS OF ROCK CLIMBING ON CLIFF GOLDENROD (SOLIDAGO-SCIAPHILA STEELE) IN NORTHWEST ILLINOIS
AMERICAN MIDLAND NATURALIST 133 (2): 229-241 APR 1995
Abstract: Solidago sciaphila is an endemic goldenrod, restricted to dolomite or sandstone cliffs in and near the driftless region of the upper Midwest. A demographic study of 544 genets on currently climbed, previously climbed and unclimbed dolomitic cliffs in NW Illinois indicated that position on the cliff face was the most significant factor affecting growth. Seventy percent of all plants grew within 3 m of the cliff top, an area that comprised only 18% of the cliff face. Within the upper cliff zone, rock climbing significantly reduced Solidago density. Cliffs that were actively climbed had few genets in the upper 3 m, averaging 3.2/m(2), while unclimbed cliffs and cliffs not climbed for 2 yr supported 14.2/m(2) and 12.0/m(2), respectively. Basal area/m(2) and flowering ramet production/m(2) were significantly lower, and inflorescence length nonsignificantly louver, on currently climbed cliffs, due to the lower genet density. In the lower cliff zone (>3 m from the top) genet density was low (0.2-2.1/m(2)) on all cliffs, regardless of climbing intensity. On climbed cliffs > 50% of flowering ramets were broken, significantly more than the 15% broken on unclimbed cliffs. Broken flowering ramets produced 22% of total inflorescence length on the currently climbed cliffs (compared to <5% on unclimbed and previously climbed cliffs), resulting in total inflorescence production statistically similar to, but lower than, that on unclimbed and previously climbed cliffs. Two years after cessation of climbing, Solidago in the upper zone of the previously climbed cliffs had similarly high density basal area, ramet production and inflorescence production as on unclimbed cliffs. Climbing appeared to skew the population structure, favoring survival of large flowering genets and inhibiting survival of smaller nonflowering genets. This difference largely disappeared on cliffs unclimbed for 2 yr. To protect Solidago sciaphila, it is necessary to protect the entire cliff face, with highest priority given to the upper 3 m.
Effects of rock climbing on the vegetation of the Niagara Escarpment in southern Ontario, Canada
McMillan MA, Larson DW
CONSERVATION BIOLOGY 16 (2): 389-398 APR 2002
Abstract: The cliffs of the Niagara Escarpment support unique and diverse plant communities. Although recreational rock climbing has become extremely popular in North America over the past two decades, little is known about the effect of this sport on the natural biota. We examined the ecological effects of rock climbing on vascular plant, bryophyte, and lichen communities along the Niagara Escarpment in southern Ontario. We made comparisons among randomly, selected climbed and unclimbed rock outcrops by, sampling from three positions: plateau (or cliff edge), cliff face, and talus (or cliff base). Density,, percent cover, species richness, and species diversity, of vascular plants were lower on climbed outcrops than on unclimbed outcrops. In addition, the proportion of alien plants was three times greater in climbed areas than in unclimbed areas. The frequency and richness of bryophyte species were also significantly, lower in climbed areas. The frequency, of lichens was the same on climbed and unclimbed cliffs, but species richness was significantly, lower in climbed areas, and community, composition differed between climbed and unclimbed areas. Our results suggest that rock climbing has significant negative effects on all aspects of the vegetative community, on cliffs. Therefore, we recommend that conservation plans be modified to include specific Policies regarding recreational rock climbing for lands containing exposed cliffs. For example, we suggest that the establishment of new climbing routes be banned in protected areas along the Niagara Escarpment.
So climbers, on the whole, tend to reduce plant cover and plant diversity, relative to similar cliffs without climbers' impacts. However, study findings differ between locations. Lichens seem to be the most sensitive to climbers. No kidding, eh? As a climber, these findings seem pretty intuitive to me.
So what about bolts? Well, the above studies didn't weigh the issue - trad climbers were viewed the same as sport climbers, as far as impacts go. Some more recent studies (more in the recreation management field) have indeed looked at bolting issues.
Here's an interesting look at modeling climbers' behavior in J-Tree, from the perspective of managing new bolting activity. My personal feeling is that the author could have used some more input from climbers in analyzing the data (most of you reading this here will have many 'duh, no kidding' responses to comments like "Fifty percent of the survey respondents ranked traditional (mostly naturally protected) climbing as their top activity whereas only 15% ranked fixed anchor protected climbing as their preferred activity." That's right - few self-identified sport climbers go to J-Tree because there are few sport climbs...). I'm also not crazy about the use of the YDS as an unbiased indicator of route difficulty, although I guess that's the best measure available. Also note that the bit about managers concern over bolts is part of the context of the study, not the results of the study itself. Anyway, enough editorializing.
Understanding Recreation Flow to Protect Wilderness
Resources at Joshua Tree National Park, California
Abstract: Joshua Tree National Park (JTNP) has the highest concentration of rock climbing routes in the world and an estimated 250,000 people visit JTNP each year to rock climb. Although less than 5% of rock climbers visit the designated wilderness areas, a steady increase in the number of climbers has
focused attention on managing wilderness climbing resources to retain wilderness character. The main controversy centers on rock climber’s placing fixed anchors, or bolts, while establishing new climbing routes. Park staff believes that continued unregulated placement of bolts in JTNP’s wilderness leads to greater impacts and is unsustainable. This paper describes a method for understanding wilderness climbing in order to develop fair and effective wilderness recreation policy. Behavior and spatial modeling is based on two years of data that include a comprehensive climbing resource inventory,
wilderness visitor flow data, and psychological test results. Static and dynamic models consider factors such as travel networks, climbing route difficulty and quality, sensitive resources, landscape complexity, and climber preferences. A comprehensive understanding of recreation flow allows fixed anchor regulations and wilderness management to address site-specific issues.
The full article can be accessed online for your enjoyment (no, I don't know if it was ever published in a peer-reviewed journal, so caveat emptor...). It's an interesting read, showing things like just how many people flock to small numbers of routes in J-Tree:
As for aesthetics, they are indeed a component of environmental impact. However, most non-climbers will not see bolts. I believe that I've heard that the non-climbing public usually feels stronger about other issues (chalk, for instance, or seeing climbers on the walls) than bolts. I did find one study that had a really nice literature review on these topics (KT Wood's Master's thesis on recreation management in Shenandoah NP). Some key excerpts:
"Jones (2004) examined visual preferences among rock climbers and non-climbers in Utah’s Rock Canyon Park concerning impacts caused by fixed anchors and climbing chalk on cliffs.
Using a series of near-view photos of cliffs containing a mix of fixed anchor/chalk scenarios (i.e. all impacts, anchor removed/chalk present, chalk removed/anchor present, all impacts removed), 143 respondents rated photos on a five-point scale according to visual preference. Results of paired t-tests suggest preferences for photos with impacts were not significantly different than photos without, and rock climbers and non-climbers did not differ in their visual preferences.
The results of this study suggest decisions to regulate the use of fixed anchors or climbing chalk on the basis of visual impacts to visitors alone may be unfounded (Jones, 2004)." (p. 17)
Furthermore, "A recent study of climbers in Adirondack State Park in New York was conducted to examine their perceptions concerning social and resource impacts of rock climbing, as well as their attitudes toward management (Monz et al., in press). The authors of the study note that the majority of rock climbing research prior to this study has focused on evaluating climbers’
attitudes towards impacts occurring on the rock face, particularly the presence of fixed anchors. Further, the authors note that cliff-face impacts such as the presence of fixed anchors may not represent the greatest threat to resources posed by rock climbing, and consequently may be over emphasized in literature (Baker, 1999; Waldrup & McEwen, 1994)."
Have a look for yourselves:
If you've read this far, you know that I agree with the last statement - bolts per se are not particularly visually offensive, and represent a very minor environmental impact relating to climbing in themselves. However, I would add that they are a significant factor insomuch as they increase the amount of rock available to climbers, and thus increase the amount of cliff ecosystem affected by climbers.