Human activities have significantly influenced high-elevation landscapes and hence also the biodiversity of high-elevation pastures and rangelands all over the world. During the last 5 decades, however, such anthropogenic highland biota often experienced dramatic alterations due to changes in land use. This book gives an excellent overview of the effects of land use change on biodiversity within high mountain ecosystems.
The 26 chapters, selected from the presentations given at 2 Global Mountain Biodiversity Assessment workshops (Tanzania, 2002; Bolivia, 2003) are organized into 6 parts. These provide a synthesis on the general aspects of anthropogenic highland ecosystems (Part I, Chapter 1); address the effects of fire (Part II, Chapters 2–7) and grazing on mountain biodiversity (Part III, Chapters 8–17), the effects of grazing on mountain forests (Part IV, Chapters 18–20), and socioeconomic aspects (Part V, Chapters 21–24); and give a synthesis of the impact of human activities on highland and mountain biodiversity (Part VI, Chapters 25–26).
Chapter 1 provides a general overview of the importance of biodiversity and ecosystem functioning in non-forested anthropogenic highland ecosystems. The focus is on the importance of quaternary history, land use, topography, microclimate, and soil properties for ecosystem functioning and biodiversity in high-elevation ecosystems.
Chapters 2 to 7 deal with the effects of fire as a driving force behind mountain biodiversity. The influence of fire on the diversity and ecology of the ericaceous belt at the treeline in the Bale Mountains, Ethiopia, is discussed in Chapter 2. The impact of fire on plant biodiversity in low Afroalpine grasslands on Mount Elgon and in low- and high-altitude forests on Kilimanjaro are addressed in Chapters 3 and 4, respectively. The effects of fire on the diversity of geometrid moths in mountain forests on Kilimanjaro is discussed in Chapter 5. Chapter 6 deals with the influence of fire on small mammals in a sclerophyllous forest at a high-elevation site in Andringitra National Park, Madagascar. In Chapter 7, attention is given to the influence of fire on species composition, vegetation structure, and biomass dynamics in mountain grasslands in northwest Argentina.
Chapters 8 to 17 focus on the impacts of grazing on the biodiversity of high mountain ecosystems. After an overview of páramo vegetation biodiversity and its relation to anthropogenic impacts in Colombia in Chapter 8, the impact of grazing on vegetation structure, species richness, and biomass production in the Venezuelan páramos is discussed in Chapter 9. Chapters 10 to 13 deal with studies on vegetation and grazing patterns in several Andean environments of Argentina, Bolivia, Peru, and Venezuela. Chapter 14 highlights grazing history in the rangelands of the Changthang plateau in eastern Ladakh, India. The impacts of grazing on the degradation and stabilization of alpine ecosystems in the Snowy Mountains of Australia are discussed in Chapter 15. Regional studies carried out in the mountains of Tajikistan address the effect of land use on desertification problems in the Pamir Mountains (Chapter 16) and discuss the effects of grazing on bio-diversity and soil erosion of alpine pastures (Chapter 17).
Studies on the effects of grazing on mountain forests deal with species diversity, forest structure and tree regeneration in subalpine woodland pastures in the Swiss Alps (Chapter 18); discuss patterns of forest recovery in grazing fields in the uppermost montane forests in the subtropical Mountains of the Sierra de San Javier in northwest Argentina (Chapter 19); and report on climatic and anthropogenic influences on the density and the distribution of Prosopis ferox forests in arid environments of Argentina (Chapter 20).
Land use and mountain biodiversity should also be seen with respect to socioeconomic aspects. Controlled grazing managed by locals can prevent overgrazing and thus promote biodiversity, as shown for the Maloti-Drakensberg of South Africa in Chapter 21. The impact of livestock grazing and resource harvesting on the biodiversity of alpine pastures in Nepal is discussed in Chapter 22. Relationships between agricultural dynamics and water resources in a páramo environment in Venezuela are examined in Chapter 23, and the impact of human management strategies combined with the complexity of the terrain in a central Andean valley in Peru on biodiversity is highlighted in Chapter 24. The 2 final contributions give a synthesis of human impacts on biodiversity in mountain areas (Chapter 25) and an outlook on future research on biodiversity in highland biota (Chapter 26).
As pointed out by the editors, upland grazing, often facilitated by fire management, is most widespread in mountain terrains. Cultivation of formerly pristine high-elevation areas for agricultural use is often associated with a loss in biodiversity, especially in the tropics and subtropics. Thus, it is the compilation of information and insights that makes this textbook a significant contribution to the literature on high mountain ecosystems.