Francisco Cuesta

Andean bear–livestock conflicts: a review

Abstract We review the state of knowledge regarding conflicts between the Andean bear (Tremarctos ornatus) and livestock. Information was gathered from the current known geographic range of the species (Venezuela, Colombia, Ecuador, Peru, and Bolivia). Andean bears are perceived as livestock predators where herding is common; bears are frequently blamed for any livestock disappearance or death. This negative perception often leads to the poaching of Andean bears by local residents and to a disregard of protected areas and conservation efforts. We found no systematic documentation of conflicts in any Andean country. Carcass dragging, feeding signs, and presence of tree and ground nests were common features of livestock depredation sites. Direct observation of cattle depredation by Andean bears was reported at 3 sites in Colombia and Ecuador. No seasonal or cyclic patterns of depredation were discerned, and evidence suggested that bear–livestock conflicts were restricted to particular sites and involved problem bears. The conservation of Andean bears requires research on rapid ways of dealing with problem bears, as well as mitigation techniques designed to reduce perceived and actual conflicts between bears and livestock.

Diverging Responses of Tropical Andean Biomes under Future Climate Conditions

Observations and projections for mountain regions show a strong tendency towards upslope displacement of their biomes under future climate conditions. Because of their climatic and topographic heterogeneity, a more complex response is expected for biodiversity hotspots such as tropical mountain regions. This study analyzes potential changes in the distribution of biomes in the Tropical Andes and identifies target areas for conservation. Biome distribution models were developed using logistic regressions. These models were then coupled to an ensemble of 8 global climate models to project future distribution of the Andean biomes and their uncertainties. We analysed projected changes in extent and elevational range and identified regions most prone to change. Our results show a heterogeneous response to climate change. Although the wetter biomes exhibit an upslope displacement of both the upper and the lower boundaries as expected, most dry biomes tend to show downslope expansion. Despite important losses being projected for several biomes, projections suggest that between 74.8% and 83.1% of the current total Tropical Andes will remain stable, depending on the emission scenario and time horizon. Between 3.3% and 7.6% of the study area is projected to change, mostly towards an increase in vertical structure. For the remaining area (13.1%–17.4%), there is no agreement between model projections. These results challenge the common believe that climate change will lead to an upslope displacement of biome boundaries in mountain regions. Instead, our models project diverging responses, including downslope expansion and large areas projected to remain stable. Lastly, a significant part of the area expected to change is already affected by land use changes, which has important implications for management. This, and the inclusion of a comprehensive uncertainty analysis, will help to inform conservation strategies in the Tropical Andes, and to guide similar assessments for other tropical mountains.

Food habits of Andean bears in the Oyacachi River Basin, Ecuador

The Andean bear may be considered an umbrella species in South America because it uses large areas and a wide diversity of habitats. In addition, protection of Andean bear habitats is directly connected to the conservation of watersheds to safeguard future water supplies. Finally, the charisma of the species has been instrumental in improving the publics attitude toward wildlife (Cuesta 1998). However, Andean bears are threatened by habitat loss and conflicts with humans (Suairez 1999). In Ecuador, habitat loss due to agricultural activities has resulted in fragmentation and isolation of bear populations (Cuesta et al. 1999, Suairez 1999), whereas poaching has contributed to population reductions. Annual bear mortality due to poaching is estimated at 70-120 individuals (Adams and Mazariegos 1994 in Suarez 1999). Information about the ecology of Andean bears is crucial to provide a more solid basis for bear conservation. Diet studies provide such important information. Our study objective was to improve the knowledge of the ecology of this species in Ecuador by examining Andean bear diets in the Oyacachi area and the habitats that provide those foods.

Delineating priority habitat areas for the conservation of Andean bears in northern Ecuador

Abstract We sought to identify priority areas for the conservation of Andean bear (Tremarctos ornatus) habitat in the northern portion of the eastern Andean cordillera in Ecuador. The study area included páramo and montane forest habitats within the Antisana and Cayambe-Coca ecological reserves, and unprotected areas north of these reserves with elevations ranging from 1,800 to 4,300 m. We collected data on bear occurrence along 53 transects during 2000–01 in the Oyacachi River basin, an area of indigenous communities within the Cayambe-Coca Ecological Reserve. We used those data and a set of 7 environmental variables to predict suitability of Andean bear habitat using Mahalanobis distance, a multivariate measure of dissimilarity. The Mahalanobis distance values were classified into 5 classes of habitat suitability and generalized to a resolution of 1,650-m × 1,650-m grid cells. Clusters of grid cells with high suitability values were delineated from the generalized model and defined as important habitat areas (IHAs) for conservation. The IHAs were ranked using a weighted index that included factors of elevation range, influence from disturbed areas, and current conservation status. We identified 12 IHAs, which were mainly associated with páramo and cloud forest habitats; 2 of these areas have high conservation priorities because they are outside existing reserves and close to areas of human pressure. The distribution of the IHAs highlighted the role of human land use as the main source of fragmentation of Andean bear habitat in this region, emphasizing the importance of preserving habitat connectivity to allow the seasonal movements among habitat types that we documented for this species. Furthermore, the existence of areas with high habitat suitability close to areas of intense human use indicates the importance of bear–human conflict management as a critical Andean bear conservation strategy. We suggest that a promising conservation opportunity for this species is linked to its occurrence in highland habitats, which play a key role in the maintenance of long-term water supplies.

Large-scale patterns of turnover and Basal area change in Andean forests.

General patterns of forest dynamics and productivity in the Andes Mountains are poorly characterized. Here we present the first large-scale study of Andean forest dynamics using a set of 63 permanent forest plots assembled over the past two decades. In the North-Central Andes tree turnover (mortality and recruitment) and tree growth declined with increasing elevation and decreasing temperature. In addition, basal area increased in Lower Montane Moist Forests but did not change in Higher Montane Humid Forests. However, at higher elevations the lack of net basal area change and excess of mortality over recruitment suggests negative environmental impacts. In North-Western Argentina, forest dynamics appear to be influenced by land use history in addition to environmental variation. Taken together, our results indicate that combinations of abiotic and biotic factors that vary across elevation gradients are important determinants of tree turnover and productivity in the Andes. More extensive and longer-term monitoring and analyses of forest dynamics in permanent plots will be necessary to understand how demographic processes and woody biomass are responding to changing environmental conditions along elevation gradients through this century.

Effects of climate change on Andean biodiversity: a synthesis of studies published until 2015

Understanding how GCC is affecting the biological diversity of the Andes is of utmost importance and timeliness given the relevance of the region for biological conservation. Our research questions were (1) what is the spatial (country-level) and temporal distribution of the scientific research exploring links between GCC and biodiversity in the Andean region? (2) What are the methodological approximations, areas of research and subjects of study most commonly considered? And (3) What are the trends in biodiversity responses most commonly found under different GCC stressors? We found that the first paper on GCC and biodiversity in the Andes was published in 2001. Since then the annual rate of publications, as well as the variety of areas of research, has risen steeply. The 65 published articles we found are likely to represent 1% of the scientific literature dealing with tropical ecology. Of those, more than half of the studies were conducted in a single country, used mostly observation rather than modelling or experimental methodological approaches, and focused mainly on plants. Studies dealing with birds, mammals and reptiles were notoriously underrepresented. The high number of GCC stressors and the great variety of responses found in this synthesis makes it difficult to draw general conclusions. However, we found that observational, modelling and experimental studies report negative GCC impacts on the biological diversity of the region. Most generally, observation and modelling studies report contractions of the distribution ranges of Andean species, and negative effects on species population densities and individual performance. We conclude our review suggesting that networking, recovering historic field data and conducting large-scale ecosystem experimental studies are critical to improve our knowledge on the effects of GCC on Andean biodiversity.

Priority areas for biodiversity conservation in mainland Ecuador

Ecuador’s territory harbors a unique set of species and ecosystems, many of them endemic to the countries’ territory and subject to different sources of threat of anthropogenic origin. Despite national and subnational conservation strategies developed in Ecuador to conserve its biodiversity in the long run, including the National System of Protected Areas (PANE) and the forest conservation incentive program SocioBosque (PSB), further actions are needed to mitigate and reverse the effects of threats for the persistence of biodiversity. This study was designed to identify the most important areas for biodiversity conservation in mainland Ecuador that can contribute to preserving key species (i.e. endemic, threatened) and ecosystems in the wider landscape, thus complementing current conservation efforts (i.e. PANE). Species distribution models and recent maps were used to identify a set of 744 species and 87 ecosystems as surrogates of the country’s biodiversity. Marxan, a systematic reserve selection algorithm was used to identify important biodiversity areas that could represent between 10% and 20% of the remnant distribution of the surrogates. The optimized solution generated by Marxan included 24% (3.64 million ha) of Ecuador′s remnant vegetation, of which 35% is within the current national protected area system and 13% (456 000 ha) are included within SocioBosque communal and private conservation agreements. Major conservation shortfalls of the PANE were concentrated in the Southern Andes, Central Amazonia, and the Central and Southern portions of the Coastal plain. The incidence of complementary criteria to prioritize conservation strategies, related to climate change, ecosystem conversion, carbon and accessibility, and population density change in relation to the important biodiversity areas was heterogeneous among regions. This confirms the need to implement differentiated conservation and sustainable landscape management strategies. Fourteen priority landscapes were identified based on these important biodiversity areas, including remnant ecosystems considered critical for maintaining large-scale connectivity among regions and preservation of restricted range and threatened species. Further work is needed to expand base information about distribution patterns of biodiversity, improve the representation of endemic and threatened species in conservation strategies, and to fully integrate conservation priorities among a wider set of goals in land use planning exercises at different scales.

Latitudinal and altitudinal patterns of plant community diversity on mountain summits across the tropical Andes

The high tropical Andes host one of the richest alpine floras of the world, with exceptionally high levels of endemism and turnover rates. Yet, little is known about the patterns and processes that structure altitudinal and latitudinal variation in plant community diversity. Herein we present the first continental-scale comparative study of plant community diversity on summits of the tropical Andes. Data were obtained from 792 permanent vegetation plots (1m2) within 50 summits, distributed along a 4200 km transect; summit elevations ranged between 3220 and 5498 m.a.s.l. We analyzed the plant community data to assess: (1) differences in species abundance patterns in summits across the region, (2) the role of geographic distance in explaining floristic similarity, and (3) the importance of altitudinal and latitudinal environmental gradients in explaining plant community composition and richness. On the basis of species abundance patterns, our summit communities were separated into two major groups: Puna and Paramo. Floristic similarity declined with increasing geographic distance between study-sites, the correlation being stronger in the more insular Paramo than in the Puna (corresponding to higher species turnover rates within the Paramo). Ordination analysis (CCA) showed that precipitation, maximum temperature and rock cover were the strongest predictors of community similarity across all summits. Generalized Linear Model (GLM) quasi-Poisson regression indicated that across all summits species richness increased with maximum air temperature and above-ground necromass and decreased on summits where scree was the dominant substrate. Our results point to different environmental variables as key factors for explaining vertical and latitudinal species turnover and species richness patterns on high Andean summits, offering a powerful tool to detect contrasting latitudinal and altitudinal effects of climate change across the tropical Andes. This article is protected by copyright. All rights reserved.

Research Priorities for the Conservation and Sustainable Governance of Andean Forest Landscapes

The long-term survival of Andean forest landscapes (AFL) and of their capacity to contribute to sustainable development in a context of global change requires integrated adaptation and mitigation responses informed by a thorough understanding of the dynamic and complex interactions between their ecological and social components. This article proposes a research agenda that can help guide AFL research efforts for the next 15 years. The agenda was developed between July 2015 and June 2016 through a series of workshops in Ecuador, Peru, and Switzerland and involved 48 researchers and development experts working on AFL from different disciplinary perspectives. Based on our review of current research and identification of pressing challenges for the conservation and sustainable governance of AFL, we propose a conceptual framework that draws on sustainability sciences and social–ecological systems research, and we identify a set of high-priority research goals and objectives organized into 3 broad categories: systems knowledge, target knowledge, and transformation knowledge. This paper is intended to be a reference for a broad array of actors engaged in policy, research, and implementation in the Andean region. We hope it will trigger collaborative research initiatives for the continued conservation and sustainable governance of AFL.

Restoring Andean Landscapes to Secure Local Environmental Services and Global Benefits

Effective landscape restoration practices require scientific knowledge about ecosystem functions, land use history, and institutional arrangements. In close collaboration with local partners, the Consortium for the Sustainable Development of the Andean Ecoregion (CONDESAN) is working to develop and assess restoration practices in Andean ecosystems. The approach combines various tools at the landscape scale, emphasizing the need to integrate restoration actions into land use planning and the importance of monitoring restoration practices. The sustainability of restoration practices remains a challenge, but the work underway will allow CONDESAN to generate sound alternatives for Andean landscapes.