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The Namche Conference: May 24-26,
2003 Participants and Presentations:
Agustina Barros and Jorge Gonnet |
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Lic. Agustina Barros Programa de Maestría en Manejo de Vida Silvestre, Centro de Zoología Aplicada, Universidad Nacional de Córdoba, Argentina; email: agustinabarros@hotmail.com, and Dr. Jorge Gonnet, Departamento de Áreas Protegidas, Dirección de Recursos Naturales Renovables, Ministerio de Ambiente y Obras Públicas Mendoza Argentina; email: jorgegonnet@hotmail.com
Impact of Tourist Activity on Mountain Vegetation and Soil NOTE: A complete draft of this paper, with figures and tables, is available in the Namche Conference Files folder at groups.yahoo.com/group/namcheconference/. (Look for "008-ab.doc".) Please let us know if you have difficulty accessing this file. ABSTRACT Aconcagua Provincial Park is located in the Andean Range at 70 31’ W 32 39’ S, in Mendoza province, Argentina. It is an ecosystem with singular characteristics due to amazing landscapes and particular biota. It belongs to the altoandina biogeographic province with predominant open grasslands and under-shrub vegetation, adapted to hard weather and poor soil conditions. In meadows, there is another kind of vegetation (Cypereacea, Junceacea) which supports long periods of frozen soils, with higher species richness and vegetation cover. Every year, during summer season the Park attracts tourists from all parts of the world, as it has the highest mountain of West Hemisphere (Aconcagua 6962 m asl). In the last 10 years the tourist activity has been increasing 10% annually, with the same tendency for mules. Around 4500 people visited the park last season (2001-2002) and around 1600 mules were used as equipment transport. It is important to quantify the environmental impacts to understand the processes and mechanisms that cause them. This study proposes recommendations for minimizing negative effects of human activities in the Park. The study was done in the intensive use area of the Park (Horcones U-shaped valley) from 2700 to 3500 meters above sea level. The impact was assesed in camp areas and trails, in dry-land vegetation and meadows. There were selected undisturbed areas with similar environmental characteristics (slopes, vegetation communities, soils, altitude) as controls. From preliminary results, we can tell that the major impact is caused by mules related to the way of transit and the lack of regulations. In places with trails the vegetation cover has a significant decrease, and in meadows the proportion of change is much greater. At lower heights (2700-2900 m asl) the frequency of exotic plants species is bigger. The major impact is punctual, restricted to defined areas (meadows, campgrounds, lower altitudes). Management through environmental education, zonification, and the control of rangers, will contribute in decreasing the negative effects and will help mountain ecosystem conservation. INTRODUCTION Aconcagua Park is located in the Andean Range at 70 31’ W 32 39’ S, Mendoza Province, Argentina. It is an ecosystem with singular characteristics due to amazing landscapes and biota. It belongs to altoandina biogeographic province, predominating open grasslands and under-shrub vegetation, adapted to hard weather and poor soils (Ambrosetti et al 1986). In meadows , there is another kind of vegetation (Cypereacea, Junceacea) which supports long periods of frozen soils, with more biodiversity and vegetation cover (Wingeroth 1992).The Park attracts tourists from all parts of the world as it has the highest mountain peak of Western Hemisphere (Aconcagua 6962 m asl). During the last 10 years the tourist activity have been increasing (10% annual), with the same tendency for mules of tranport. Around 4500 persons had visited the park last season (2001-2002). Detailed description of climatic change in the recent Quaternary (Wingeroth 1992), research in Geology (Ramos 1996), Glaciology (Espizua 1993, Videla 1996), Mountain Exploration (Reichert 1929, Punzi and Ugarte 1952), and plant inventories in surrounded U-shaped valleys (Wingeroth and Suarez 1984) were made in the Aconcagua Region but there is a lack of information about biological community ecology, anthropogenic impacts and long term sustainability concerns, contemporary trends, problems and prospective solutions. It is important to quantify the environmental impacts to understand the processes and mechanisms that cause them. This study proposes recommendations for minimizing negative effects of human activities in the Park. METHODS The area was divided in three altitudinal sectors according to their features and characteristics (plant communities, slope, geomorphic units). The classification and estimation of vegetation patches surfaces was done by visualization and digitalization of a satellite image (LANDSAT 5 TM January 2000) using the ERDASS GIS system. 48 line transects were systematically arranged perpendicular to the ridgeline, both in trail zones and adjacent control sites (Figure 1). The following variables were estimated in every transect along the 12 kms of the study site: impact zone width, vegetation species cover and plant richness. All transects were recorded with a hand held GPS to facilitate relocation and method replication for possible future studies. Plant sample collection for herborization and taxonomic classification was performed. Although individual species were identified for statistical analysis, plants were grouped in 4 categories in dry-lands (shrubs, grasses, herbs and exotic species), and in 5 groups in meadows (herbs, grasses, Cypereaceae, Junceaceae and exotic species). The line transects started at the first trail and went perpendicular to the last one. Variables recorded included number of trails, individual trail width and depth. The percentage of ground cover (rock/denude soil) and plant cover was estimated by using the Point Quadrat method along the line transect. All vegetation or “ground touches” on a vertical pole (placed every 0.2 m2) were recorded on every transect. Four 0.5-m2 random sampling plots were established along the transect line to estimate species richness. The same variables were surveyed at control sites, with the exception of trail impact variables (social trail number, trail width and depth) (Fig.1) To know the procceses that influx in trail impact, parametric and non parametric analyisis by using ANOVA’S between sites (4) and treatment (disturbed sites and undisturbed sites) were done. In order to understand the historical, contemporary human use and Park management, the information related to legislation, politics, research activities and other important information recorded by the public agency was compiled and reviewed . Interviews were performed to the public agency and questionares to park visitors were also conducted. The identification of mule’s and hiker’s routes as well as mule’s grazing and rest areas were established by direct observations. Fig.1 Field area sampling in Horcones Valley, Aconcagua Provincial Park. Trail area Control Site Fig. 2. Line transect located in the ridge line to estimate soil variables ( trail width and depth, ground cover) and vegetation variables (species richness and plant cover). Fig. 3. Radial line transect to estimate vegetation and soil variables in Confluencia Campsite and control Site. RESULTS The Central Andes mountain ecosystem is a cold and harsh environment with poor and thin soils, which implies a low plant cover adapted to hard weather conditions and high altitudes (2000-6000 m asl). Among direct impacts in alpine vegetation, trampling effects are commonly small in area, compared with agricultural land use, but they rather affect sensitive terrain, which would be better not to be touch on (e.g dwarf shrub vegetation in the lower, and fragmented vegetation in higher alpine zone, on steep slopes in particular) (Korner 1999). The study area includes a surface of 6890 hectares, which only 32% have vegetation cover: 30% corresponds to dry-land vegetation and only 2% corresponds to meadow vegetation. Having an equal use in dry land and meadow environments, it was observed that the proportion of change in plant cover was much greater in meadow vegetation because they appeared to be more fragile to trampling and campground impact. Changes weren’t observed in species richness due to trampling. Lower parts and meadows presented more vegetation cover and richness. The proportion of denude soil in dry-lands disturbed sites increased 2 times more than in control sites, and in meadows the increment was 6 times more. At disturbed sites it was observed that vegetation cover was similar between lower (2700-3000 m asl) and higher sites (3000- 3500 m asl), indicating an incipient process of desertification. The number of social trails was high in the entire site (7 trails average), being the impact intensity bigger in wet habitats. This effect was influenced by the hikers way of transit, because they usually avoid muddy places producing new routes. Also, stock animals cut across meadows, producing loss of vegetation and soil. In addition, mules tend to produce more impact intensity on ground cover due to the pressure exerted on their foot. Plant categories presented similar results in trails and campgrounds. In dry-lands, shrubs and grasses appeared to be more affected by these activities, having a bigger decrease on vegetation cover. Herbs were tolerant to impact, presenting more frequency in disturbed sites. Grasses suffered an additional impact, as they constitute the forage species for packstock in the study site. A plant specie, Adesmia subterranea, which lives in a narrow altitudinal range (3300-3500 m), presented to be highly vulnerable to trampling, only appearing on undisturbed sites. In meadows, Cypereaceas were more susceptible to damage, decreasing their plant cover more than 2 times in traffic sites. At campsite, vegetation cover had a total loss in the core area (25 m). Meadows affected showed a drying proccess. There were 42 species identified in the study site, of these 4 were exotics species. These 4 were concentrated in the lower parts of the Park, between 2700 and 3000 m asl. In Confluencia Campsite, at 3300 m asl, no forage species were found ( Table 1, Annex 1). There were some anthropogenic factors identified that could have a negative effect on vegetation and soil impact. Review of legislation and field observations shows that the Park is only strict in some regulations considered to be of special importance (eg. exclusive use of letrines and garbage management). On the other hand, certain regulations on some activities of special interest due to the effects they cause on vegetation and soil, aren’t actually controlled and/or are difficult to implement without other management actions. As an example, mule grazing is forbidden in all Park areas. On this point, we have to take into account that the distance from the Park entrance (2700 m asl) to Base Camp ( Plaza de Mulas 4375 m asl), where mules load and unload mountain equipment, is 40 km long. As park rangers are located only at campsites, it is not possible to achieve an effective control along the entire traffic route. Because of this factor, they should select special interest sites for control, such as places more susceptible to damage (meadow vegetation, Adesmia subterranea plant communities). Another regulation without an effective application is the exclusive use of designed trails indicated with signs. Actually there is not any order on traffic routes. Trails are not clearly defined and there are a lack of signs posted. Although there is a regulation that establishes the trip of one rider “arriero” for every 3 mules, it is common to observe all the stock animals together (30-40 mules) with riders behind them, producing a disorder in the traffic and the generation of new trails. Furthermore, the information provided to visitors is only focused on climbing aspects (access routes, medical assistance services, climbing recommendations) mountain safety and laws that are consider to be important for park conservation (e.g exclusive use of letrines and management of garbage). Visitor interviews showed that climbers have no interest in receiving information about natural characteristics and conservation aspects of the Park. Despite this, it is general knowledge that sometimes the visitors are simply ignorant about the importance of this subject, so the implementation of certain techniques (low impact education) could result in a minimum level of impact. Environmental education for visitors should be a more important issue in order to minimize impact. This could be done through environmental techniques (trailhead design, displays, audiovisual techniques) (Hammit and Cole 1998) RECOMMENDATIONS FOR MANAGEMENT According to the results obtained in this work (Barros 2002, in revision) and field observations, it is necessary to develop a Management Plan in the Park. To diminish the impact on vegetation and soil, certain techniques should be implemented taking into consideration visitors and site management. In order to know the effectiveness of the actions, a Monitor Plan should be developed because it is an integral part of the management process. Visitor management Low impact techniques and environmental education are the key factors to manage recreational activities (Hammit and Cole 1998). It is recomended to establish the following actions: Environmental Education Program It is important to train park rangers and private agents (climbing companies, mountain guides) in natural and conservation aspects of the protected area that they acquired, so they can transfer the knowledge to visitors. The regulations that visitors would have to obey should be clear and easily transmitted by an educator ( e.g park rangers, mountain and tourist guides). Low impact education information should be included in brochures and signs. Signs should be located on specific sites, such as paths, principal points (Park entrance, campgrounds), sites susceptible to damage and closure places. The signs on closure sites should address the reasons why the area is restricted and how users contribute to its preservation by not using that area. On this point, it has been proven that this type of information increases the visitor’s desire to conserve the area under restoration (Eagle Cup Wilderness, Oregon)(Cole et al 1997). In most visited places, such us Horcones Meadows and Confluencia self-guided trails should be designed in order to delineate trail areas and offer more information about the Park. Stock animals management and evaluation of other possible alternatives for transportation. Packstock management is a priority corncern in Aconcagua Park. Firstly, strict control on mules traffic should be implemented by locating signs barring transit and grazing in sensitive patches and undisturbed sites. Because of the additional impact that mules cause at campgrounds (footpath and grazing, remotion of shrubs, soil compaction and erosion) a designated area should be located at trail head facilities for loading and unloading mules. Alternative ways of transport should also be evaluated. Some comparative studies have assesed the differences in trampling intensity disturbance between llamas, horses and mules, observing that hikers and llamas produced much less damage (Markham 1990, Cole and Spildie 1998). In Peru (Cordillera Blanca, Prom-Perú ONG’S) they have developed a program using llamas as tourist transport in natural protected areas. According to these experiences and studies, it would be interesting to design a pilot project in Aconcagua Park with the use of llamas as transport animals. Some of the aspects that have to be on consideration are: animal adaptability to height and travel distance, animal management, the number of llamas to carry the equal weight of mountain equipment and the social acceptance of this new way of transportation. On the other hand the advantages and disadvantages of using a helicopter as transportation shoud be taken into account. About the advantages, we can mention the decrease of mules impact on vegetation and soil and a quicker an safer way to transport the equipment. Among the disadvantages, we can mention noise and visual pollution that the helicopter would produce with the consequent anoyance for visitors and the possible wildlife displace. Another problem is the decrease of rider’s jobs, that could be minimized through programs that substitute their actual employment for other job positions (Gonnet 2000). Finally, to evaluate the alternatives mentioned here, all aspects have to be on consideration (social, environmental and economics) in an integral way and with the participation of all the people involved in it. Site management Site management is a key factor to minimize the impacts in the area and to restore highly disturbed sites. It’s important to establish a zonification considering the following aspects:
Selection and organization of trail zones and campsites The zonification has to be done by sectors, using technical criteria like places more susceptible to damage, resistance sites, number of users and existing trails. World experience (Mountain Parks in United States and Canada) and National experience (Sierras Grandes de Córdoba, Argentina) demonstrate that improvement of trail areas and disturbed site restoration (reforestation with native species, trail consolidation, control drainage, swtichbacks, among others), could minimize the impact produced by human activities in vegetation and soil (MacDonald 1997, Renison 2001) The priority areas for conservation in the study site are: - Wet habitats Horcones meadows (2700-2900 m asl) are one of the most fragile areas with the largest amount of visitors. Despite this factor, the actual regulations include this area for intensive use.being a priority to restablish a new category for the site . Actions to be implemented are: Mapping susceptible sites for restoration and selection of conservation sites Establish closures (signs along trails, fences, switchbacks, stones) in order to exclude packstock and visitors trampling Improve existing trails - Design self-guided trail for visitors Use of existing roads for mules Design and implementation of a Monitor Plan The results obtained on the mentioned work (Barros 2002, in revision) permitted to know some aspects of the acumulated impact of 20 years of intensive touristic activity in Aconcagua Park. Nevertheless, the fact that ecological cycles of mountain plant species are really fast and secuencial during the summer season, it is recommendable a monthly register of impact procceses and plant species life cycle and systematic surveys in the same sites in the beginning and the end of the season. This information would be an useful tool for establishing effective management actions. Two aspects in the Monitor Plan are of especial corncern: long term planification and the easy application of the plan for managers and park rangers. Specif forms have to be designed for surveys explaining in a clear and detailed way, the procedures to be filled. -Trail conditions monitoring It is recommended to establish replicable measures along the transects in order to quantify the amount of change in vegetation and soil variables, before and after each summer season. For this purpose, fix sticks should be located to relocate measured places. The frequency of surveys and spatial design of samples would depend on the objetive and the indicator selected.The variables could include:
The delimitation of trail areas and closure of parallel trails has to be monitored for evaluating the effectiveness of the actions implemented and realice modifications when is necessary. Measures in specific segments (susceptible sites, pronounced slopes, erodable soils) also is recommendable. -Vegetation variables For vegetation monitoring at least one survey season has to be executed each summer. The variables for monitoring are:
1. Proportion of surficial ground (denude soil, rocks)
In all sectors should be establish sites for control. It would be recommendable to map the vulnerable sites (e.g Adesmia subterranea plant communities, Cypereacea) in the Park to determine priority sites of conservation. To know and understand plant responses to impact, specific studies should be realized about natural history. Systemic surveys about the advance and involucrated procceses in the expansion of exotic species (e.g: Convolvulus arvensis, Nicotiana corymbosa) are also important. Recovery sites monitoring To monitor Confluencia Campground it will be use the same transects made for the mentioned study and folow the recovery rate of impact vegetation The results obtained in the propose study would help to determine the protection category. In case of identifying irreversible damages, it should be evaluated the posibilities of implementing other management tools for restoration (eg. reforestation) Implementation of a Management Plan In order to implement this, it is necessary to count with economic resources. Although the Park has it’s own income through the payment of acces permits, it’s not enough for implementing a conservation program due to the manteinance and operative costs (salaries, helicopter and medical service, mountain equipment for employees, among others) (Perelló com.pers). Because of this factor it is a priority to generate new incomes sources. Among the possible sources, private enterprises constitute a potential contributor, as they have a great income each summer season (could reach around U$S 50.000). Actually they only pay a season permit of only $800 (argentinian pesos), not depending on the income that they have. Considering these aspects, the goverment agency should establish different canons according to enterprise dimensions, as bigger enterprises generally make greater impacts to ecosystem (major quantity of tents in campsites, more stock animals and climbers) Another potential source is a sale shop for souvenirs of Aconcagua Park (posters, books, key holder, among others ) and information material about the different features of the Parks (maps, brochures, research information, flora and fauna) It is important that all the actors participate in the development of the Management Plan (tourists, enterprisers, researchers, research institutions, public agencies) in order to have a real application, with the previous knowledge of the needs and conflicts of the involucrated actors. Literature Cited AMBROSETTI, J.A, DEL VITTO, L.A, y F.A. ROIG.1986. La Vegetación del Paso Uspallata, Provincia de Mendoza, Argentina.Veroff. Geobotánica. ETH, Stifung Rubel, Zurich. BARROS, A. 2002. Impacto del uso público sobre el ecosistema de la Quebrada de Horcones, Parque Provincial Aconcagua, Mendoza, Argentina. Tesis de Maestría en Manejo de Vida Silvestre. Universidad Nacional de Córdoba. COLE, D.N., T.E. WATSON, D.R HALL y D.R. SPILDIE. 1997. High use destination Areas in Wilderness: Social and Biophysical Impacts, Visitor responses, and Management options. USDA Forest Service Research paper INT-483.38. COLE, D.N y D. R.SPILDIE. 1998. Hiker, Horse and llama trampling effect on native vegetation in Montana, USA. Journal of Environmental Management. 53:61-71. DRNR. 2001. Ingresantes al Parque Provincial Aconcagua. Documento Interno. Gobierno de Mendoza. ESPIZUA, L.E. 1993. Glaciaciones cuaternarias. XII Congreso Geológica Argentina y II Congreso de Exploración de Hidrocarburos. Geología y Recursos Naturales de Mendoza. V. A Relatorio, 1 (15): 195–203. HAMMIT, W.E. y D.N.COLE. 1998. Wildland Recreation: Ecology and Management. Ed.John Wiley and Sons .367 pp. MACDONALD, S. y P.C HELLMUND.1998. Planning trails taking wildlife in mind, Trails and Wildlife Task force. Colorado State Parks. MARKHAM, D. 1990. Llamas are the ultimate. Idaho falls, ID: Snake River Llamas.286 pp. PUNZI, O.M, UGARTE, V.J y M.BIASEY. 1953. HISTORIA DEL ACONCAGUA Cronología Histórica del Andinismo. Buenos Aires. KORNER, C.1999. Alpine Plant Life. Functional Plant Ecology of High Mountain .Berlin:Springer-Verlag. RAMOS, V.A y M. B AGUIRRE-URRETA. 1996. Geología de la Región del Aconcagua. Provincia de San Juan y Mendoza. Dirección Nacional de Servicio Geológico. Anales 24 (15):423-446. REICHERT, F. 1929. La Exploracion De La Alta Cordillera De Mendoza.Universidad Nacional de Buenos Aires. Buenos Aires.300 pp. RENISON, D. 2001. Programa reforestación con especies nativas en Sierras Grandes, Los Gigantes, Córdoba. Club Andino Carlos Paz. Inédito. VIDELA, M. A. 1996. Fluctuaciones del Glaciar de los Horcones Superior y variabilidad climática. Tesis de Doctorado. Universidad Nacional de Cuyo. Facultad de Filosofía y Letras. WINGEROTH, M. y J. SUAREZ. 1984. Flores de los Andes. Alta Montaña de Mendoza. Quebrada Benjamín Matienzo 3100-4000 msnm. Cordillera Principal. Andes Centrales Argentina. Ed. IANIGLIA. WINGEROTH, M. 1992. La Quebrada de Matienzo Su naturaleza presente y pasada. Imprenta oficial. Mendoza. República Argentina. |
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