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

Abstract:

The tree species Alnus acuminata and Morella pubescens, native to South America, are candidates for soil quality improvement and afforestation of degraded areas and may serve as nurse trees for later inter-planting of other trees, including native crop trees. Both species not only form symbioses with arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF), but also with N2-fixing actinobacteria. Because tree seedlings inoculated with appropriate mycorrhizal fungi in the nursery resist transplanting stress better than non-mycorrhizal seedlings, we evaluated for A. acuminata and M. pubescens the potential of inoculation with mycorrhizal fungi for obtaining robust tree seedlings. For the first time, a laboratory-produced mixed AMF inoculum was tested in comparison with native soil from stands of both tree species, which contains AMF and EMF. Seedlings of both tree species reacted positively to both types of inocula and showed an increase in height, root collar diameter and above- and belowground biomass production, although mycorrhizal root colonization was rather low in M. pubescens. After 6 months, biomass was significantly higher for all mycorrhizal treatments when compared to control treatments, whereas aboveground biomass was approximately doubled for most treatments. To test whether mycorrhiza formation positively influences plant performance under reduced water supply the experiment was conducted under two irrigation regimes. There was no strong response to different levels of watering. Overall, application of native soil inoculum improved growth most. It contained sufficient AMF propagules but potentially also other soil microorganisms that synergistically enhance plant growth performance. However, the AMF inoculum pot-produced under controlled conditions was an efficient alternative for better management of A. acuminata and M. pubescens in the nursery, which in the future may be combined with defined EMF and Frankia inocula for improved management practices.

Abstract:

Geographic Information Systems and Remote Sensing are important contributors to Sustainable Forestry Management Plans. Remote sensing techniques for image interpretation provides the means to extract valuable information that could be expensive and time-consuming to obtain through field observations (Franklin et al. 2001). Spatial Products derived from the interpretation of airborne and satellite borne images feed Geographic Information Systems to develop strategies and methodologies for resource management, harvest planning, fire management, map production, and model predictions. (Yusmah et al. 2015) This study has three important objectives: to test the feasibility of template matching for the identification of single pine tree crowns, to conduct a delineation of pine plantations using relational features and to evaluate how single tree crown size affects the accuracy of the proposed method. Templates of single trees were produced in the software eCognition Developer. The sampling process comprised the random selection of 3000 single pine trees in 7 different test sites (test sites were grouped in 3 categories according to the single tree sizes). A first rule set to detect single tree crowns was developed in eCognition Developer, using three different template groups (4, 8 and 16 templates). Through an analysis of variance, the number of single tree crowns detected was compared for the different template groups. Using a second rule set in eCognition, the template matching algorithm combined with relational, spectral and contextual information were applied to delineate pine plantation areas. An accuracy assessment was performed in the test sites for all thematic classes identified. Finally, an Analysis of Variance evaluated the influence of single tree crown size on the overall accuracy. Potential applications and improvements to the proposed methodology for single tree crown detection and plantation delineation are proposed at the end of the document.

Abstract:

Arbuscular mycorrhizae are important for growth and survival of tropical trees. We studied the community of arbuscular mycorrhizal fungi in a tropical mountain rain forest and in neighbouring reforestation plots in the area of Reserva Biológica San Francisco (South Ecuador). The arbuscular mycorrhizal fungi were analysed with molecular methods sequencing part of the 18S rDNA. The sequences were classified as Operational Taxonomic Units (OTUs). We found high fungal species richness with OTUs belonging to Glomerales, Diversisporales and Archaeosporales. Despite intensive sampling, the rarefaction curves are still unsaturated for the pristine forest and the reforestation plots. The communities consisted of few frequent and many rare species. No specific interactions are recognizable. The plant individuals are associated with one to ten arbuscular mycorrhizal fungi and mostly with one to four. The fungal compositions associated with single plant individuals show a great variability and variety within one plant species. Planted and naturally occurring plants show high similarities in their fungal communities. Pristine forest and reforestation plots showed similar richness, similar diversity and a significantly nested structure of plant-AMF community. The results indicate that small-scale fragmentation presently found in this area has not destroyed the natural AMF community, at least yet. Thus, the regeneration potential of natural forest vegetation at the tested sites is not inhibited by a lack of appropriate mycobionts.

Abstract:

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.

Abstract:

Abstract: For the first time in tropical mountain rain forest, arbuscular mycorrhizal fungal richness and community composition was investigated from planted seedlings of Cedrela montana, Heliocarpus americanus, Juglans neotropica and Tabebuia chrysantha in reforestation plots on degraded pastures. A segment of fungal 18S rDNA was sequenced from the mycorrhizas. Sequences were compared with those obtained from mycorrhizas of adult trees of 30 species in the neighboring, pristine tropical mountain rain forest. In total, 193 glomeromycotan sequences were analyzed, 130 of them previously unpublished. Members of Glomeraceae, Acaulosporaceae, Gigasporaceae and Archaeosporales were found in both habitats, with Glomus Group A sequences being by far the most diverse and abundant. Glomus Group A sequence type richness did not appear to differ between the habitats; a large number was observed in both. Glomus Group A sequence type composition, however, was found distinctly different. Seedlings were rarely colonized by fungi of the pristine forest but trapped a number of fungi known from other areas, which were rarely found in the pristine forest.