Environmental changes in biodiversity hotspot ecosystems of
South Ecuador: RESPonse and feedback effECTs (FOR2730)

Resumen:

Human influence and its impacts are perceptible in all ecosystems resulting in land transformation, changes in global biogeochemistry, climate change, and loss of biological diversity. Mapping the spatial and temporal patterns of human influence is essential to address land use management and conservation programs. In this study, we tailored the Human Footprint index (HF) developed at global level to evaluate the spatial and temporal patterns of human pressure in South Ecuador for 1982, 1990 and 2008. Landscape and ecosystem levels were analyzed to identify the contribution of different human proxies to the HF.We also used the HF to evaluate the effectiveness of protected areas to reduce human pressure in the surrounding landscape. We found that levels of human pressure increased and the wildest areas decreased since 1982. We identified important “hotspots of changes” in the seasonally dry forests in the western part and the premontane evergreen forest in the eastern part of the study area. Our results show that each human proxy contributes in a different way to the observed values of HF in the studied ecosystems. Finally, we found that Podocarpus NP, the most important protected area in our study region, seems to be partially effective in reducing human pressure inside and in the buffer zones where only a low increase in HF was detected. However, the HF values observed in the surrounding landscape were higher than those observed in the buffer zone and inside the protected area. We demonstrated that HF could be a useful regional evaluation tool to facilitate conservation planning.

Resumen:

The South Ecuadorian Andes are one of the hottest global hotspots of biodiversity and currently threatened by land use and climate change. Forest structure and composition are crucial factors for understanding the capacity of forest support species in changing environments. In order to prioritize limited conservation resources a better understanding of tree diversity patterns is needed. The use of image texture measures, as a proxy for spatial and forest structure has shown useful possibilities in explaining patterns of tree diversity and species richness. My goal was to evaluate the performance of different texture measures on NDVI, EVI and two broad-band combinations on high resolution (0.3m) aerial photography to predict tree diversity. Bayesian Model Averaging (BMA) was used to relate in situ measurements of tree diversity to measures of image texture. Texture explained up to 44.7% of the variability of tree diversity with measures related to habitat heterogeneity, particularly variance, providing highest explanatory power. Image texture measures bear considerable potential for predicting tree diversity in the tropics and can contribute to improvements on conservation efforts and management planning.

Resumen:

Field studies have shown a wide array of responses of vascular epiphyte diversity to human disturbance-assem- blages of disturbed habitats range from largely unchanged to severely impoverished when compared with intact forest. This variability is not well understood. We explored the hypothesis that the relative impoverishment of disturbed-habitat epiphyte assemblages is a function of local climate, by analyzing the available literature on epiphyte diversity on isolated trees as a model system. We found that assemblages of moist and moderately seasonal areas experience considerably stronger impov- erishment than those of aseasonally wet or distinctly dry areas. We argue that the integrity of the vertical microclimatic gradient is more crucial for the maintenance of epiphyte diversity in moderately seasonal forests than in distinctly dry or aseasonally wet forests.

Resumen:

South America hosts 22% of the world´s forests with its unique biological diversity. Among all countries Ecuador is considered being the country with the highest biodiversity. But unsustainable land use and forestry practices threaten this diversity. Up to today Ecuador has the highest deforestation rate of the South American continent. To combate against those high forest losses wide-ranged reforestation has to take place but is still lacking in Ecuador. The reforestation efforts up to now do not compensate the high losses in forest cover. 90% (3500ha) of the annual reforestation in Ecuador is taking place in the Andean region (FAO 2006, 2011). A common tool to reinstall the forest cover is plantings. To this day 140,000 ha of forest plantations exist in the Andes of Ecuador. The commonly used species are Eucalyptus globulus, Pinus radiata and Pinus patula. Just recently Ecuadorian organizations paid particular attention to tree species native to Ecuador and their reforestation potential. The major obstacle to use native species on a larger scale for reforestation is the lack of adequate knowledge about their physiological and silvicultural traits. Information about appropriate seed storage, propagation methods and silvicultural treatment options has to be acquiered, applied and its experience communicated. Tree seed programs provide a valuable framework to deal with such sets of questions and research needs. The Danish International Development Agency (DANIDA) has over 50 years of experience in the development and establishment of national tree seed programs. Their development framework is used as an orientation in the course of this thesis to frame a regional seed program for the provincial region of Loja. The general objectives of this thesis are to evaluate the current seed procurement and management methods in the Province of Loja and to develop a concept for regional seed program for the province of Loja which is practicable and adapted to the local circumstances. Data on the current practices was gathered through a questionnaire survey and structured observation among the provincial tree nurseries. National and regional forestry strategies and plans were revised to understand the encountered situation. To develop the regional seed program the national tree seed program framework from Danida was consulted. This study assesses the main areas of improvement of the provincial seed management and highlights local facts in need for special consideration in the scope of a regional seed program. Furthermore essential parts and how to best implement those in a regional seed program are discussed. Major results involve the formulation of four main areas of improvement common for all surveyed tree nurseries of the province: Infrastructure, workforce, documentation and seed handling itself. The individual performances of the nurseries were ranked to get a clearer picture about the production efficiency. The survey also revealed the variety of tree species produced. Regarding the regional seed program the results picture the Gobierno Provincial de Loja (GPL) as a suitable entity to be in charge of the program. Moreover important stakeholders beneficiary for the program were detected and an exemplary distribution of activities among them was conducted. The principal contributions of this thesis consist in conducting a systematic evaluation of the current status of the seed sector in southern Ecuador and particularly in the Province of Loja for the first time, and in providing the provincial government with an elaborated concept to improve the seed management. Additionally the developed ranking scheme can serve as a guideline for further nursery performance evaluations.

Resumen:

We usually have only limited knowledge about the economic consequences of land-use decisions, thus they are uncertain. We analyze the implications of this uncertainty on conservation payments (CP) to preserve wildlife-friendly shade coffee production in southwest Ecuador, when conversion to maize is the most profitable alternative. Our objective is twofold: First, we analyze the consequences of applying Stochastic Dominance (SD) to derive CP, an approach making only minimal assumptions about the preferences of farmers. Second, we investigate the effects of land-use diversification to reduce CP by allowing for shade coffee on part of a landholding, and maize production on what remains. CP derived by SD turned out to be at least twice the amount calculated by an alternative method which maximizes a concave utility function?US$ 166 to US$ 294 ha-1 year-1 instead of US$ 86 ha-1 year-1. Given this result, we doubt that the assumptions underlying SD are reasonable for farmers, who are known to be riskaverse. Allowing for land-use diversification has a significant impact on CP. The optimal portfolio share of shade coffee is 27 % and for maize 73 % for moderately risk-averse farmers?without any CP. A larger share of shade coffee is preferable for strongly risk-averse farmers?51 and 49 % maize. The amount of CP necessary to encourage the expansion of shade coffee to 75 %is US$ 40 ha-1 year-1 (for moderately risk-averse) and US$ 19 ha-1 year-1 (for strongly risk-averse farmers). Stimulating diversification may thus help to significantly reduce CP necessary to preserve less profitable agroforestry options.