Programme - Projetos de I&D
Execution dates - 2013-06-01 - 2015-05-31 (24 Months)
Funding Entity - FCT
Total Funding - 180 972 €
Proponent Institution - CFE
Soil mutualists - mycorrhizal fungi and symbiotic nitrogen-fixing bacteria - and seed dispersers are essential components of terrestrial ecosystems that play a major role in the maintenance and evolution of biodiversity, ecosystem stability and productivity,and the biology and ecology of forest trees (1, 2). These below and aboveground interactions are key processes not only for maintaining long-term sustainable ecosystems but also for the regeneration and restoration of plant communities. Nevertheless, there is a general lack of information on these basic ecological interactions in tropical African forest ecosystems, which is even more critical for Mozambique given the impacts of long-standing civil wars. Therefore, basic and applied ecological research in these areas is a global priority for conservation, even more urgent due to the increasing human pressure and associated deforestation in protected areas such as the Gorongosa National Park in Mozambique.
Legumes are well represented in tropical African forests and can be the dominant species in some ecosystems such as the miombo woodlands (3). However, their nodulation and nitrogen-fixing status and their role in nutrient dynamics in tropical forests and miombo woodlands is virtually unknown (3). Similarly, a high proportion of the studied African trees establish interactions with arbuscular mycorrhizal (AM) and/or ectomycorrhizal (ECM) fungi, but most of these data come from just a few sites and regional and edaphic differences might be expected (4). There is also very little information on the effectiveness and functioning of these symbiosis in African ecosystems and on their putative role in relocating nutrients among different individuals, thus, facilitating seedlings establishment. Ecosystem disturbances such as deforestation and land use changes can result in a significant loss of the diversity of soil mutualists, although controversial reports exist on this topic. Standardized studies of different groups of soil mutualists in pristine and deforested areas in Gorongosa will provide a baseline to address these questions and a better understanding of the impacts of deforestation on plant-soil interactions. Over 80% of tree species are dispersed by endozoochory in some tropical rainforests. Seed dispersal by animals in these forests involves highly diverse plant and animal communities, and, therefore, results in a wide array of interactions. Birds are the predominant dispersers of many woody pioneer plants, but mammals - including mega-herbivores, primates, bats and rodents - are
also important in some ecosystems (5, 6). Deforestation directly affects fruit availability for seed dispersers and can have severe consequences in animal populations. However, remnant forest trees, early colonizing trees or planted trees used in reforestation offer food and/or perch sites to frugivores, promoting seed deposition and natural regeneration (5). Data on the actual vectors of seed dispersal in pristine forests is essential to understand the impacts of deforestation on this process and the importance of seed dispersers in ecosystem recovery. In addition, studying the emergence of seedlings in open areas will provide empirical evidence of
the role of different dispersers, soil mutualisms and plant facilitation on natural regeneration, which is essential for the recovery of Gorongosa forests and woodlands.
All interactions in an ecosystem can be visualized as ecological networks, in which species are linked together, either directly or indirectly through intermediate species. Ecological networks, although complex, have well defined patterns that illuminate the ecological mechanisms underlying them and promise a better understanding of the relationship between complexity and ecological stability (7). For this reason, building multilevel ecological networks that integrate below and aboveground interactions is the most realistic way of visualizing ecosystem functioning and, thus, a primary objective of this project.
In short, this project aims at assessing the diversity of key below and aboveground organisms and interactions in the unexplored montane forests and miombo woodlands of Gorongosa, visualizing these multilevel ecological networks in pristine and degraded areas and using these to interpret patterns of natural regeneration. An ultimate goal is to produce new critical data that can assist in the reforestation and conservation of tropical forests and woodlands. Since conservation depends on the involvement of the whole society, a general objective of the project is to communicate our results to a broad audience contributing to raise public awareness on ecological principles and on the importance of biodiversity for human wellbeing. The multidisciplinary team behind this proposal, with extensive experience in below and aboveground plant interactions, conservation and science communication is a solid assurance of the successful completion of all tasks.