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Taking into account the current understanding of a system by farmers is an important starting point in every project aiming at the economic and social development of human beings. In the process of organic certification of coffee growers, training sessions on various topics are conducted. In addition to these sessions, there are field visits to farms by experts. And it is most often done through a top-down approach. A household survey was carried out on a purposive sample of households in the zone of the central plateaus in Burundi. Data were collected using a questionnaire through smartphones. Data analysis was carried out using IBM SPSS Statistics software by calculating means, frequencies and cross-analyses of variables. Results show that, besides bananas that are deliberately considered as shading crops, Grevillea robusta is the most frequent shade tree which is present on 62% of coffee plots. It is followed by an indigenous tree: Ficus sp. which is present on 14.6% of plots, and a fruit tree, Persea americana present on 13.9% of plots. The effects of shade trees on soil properties are well recognized by farmers. For their search of certification (75% of farmers are involved in the process of organic certification), chemicals application is banned. Farmers use a locally-made biopesticide decoction. They prepare it from a set of five plants: Tephrosia vogelii, Solanum aculeastrum, Neorautanenia mitis, Capsicum frutescens, and Tithonia diversifolia. This research has proven that the integration of shade trees in coffee plots is a reality in the region.

This study aims to (1) estimate the effect of Sericostachys scandens density on the species richness of woody species development stages, and (2) evaluate the variation in floristic composi...

Objectif: Cette etude visait a inventorier les hemi-parasites Loranthaceae et Viscaceae occasionnant des degâts sur les arbres et arbustes des forets et des milieux agricoles du Burundi ainsi que leur ampleur d’infestation. Methodologie et Resultats: L’etude a ete conduite dans toutes les zones agro-ecologiques du pays dans les forets et les milieux agricoles environnants. Apres prospection, 98 sites repartis sur 192 ha ont ete retenus sur base de l’abondance des individus parasites. Au total, 15 especes hemi-parasites ont ete inventoriees dont 11 Loranthaceae et 4 Viscaceae. La crete Congo-Nil presente la plus grande diversite avec 8 especes sur les 15 tandis que la plaine de l’Imbo et la depression du Kumoso ne comptent que 2 especes chacune. Nonante cinq especes hotes reparties dans 64 genres et 37 familles ont ete recensees dont 47 % sont infestees par Phragmanthera usuiensis . Concernant l’ampleur d’infestation, le taux le plus eleve se rencontre dans la depression du Kumoso tandis que l’intensite d’infestation est la plus forte dans la depression du Nord-Est. Elle est dominee par 3 especes: Phragmanthera usuiensis , Phragmanthera capitata et Agelanthus flammeus . Conclusion et application des resultats: L’etude montre une forte infestation des milieux agricoles et forestiers burundais par les Loranthaceae. La lutte par suppression des touffes est peu efficace. Une strategie de lutte plus efficace a l’echelle de tout le pays devrait etre etudiee. Mots cles: Infestation, Loranthaceae, Viscaceae, zone agro-ecologique English Title: The Loranthaceae and Viscaceae parasites of Burundi's forests and agro-ecosystems: diversity and extent of infestation English Abstract Objective: The purpose of this study was to inventory the Loranthaceaes and Viscaceae as parasites causing damages on trees in Burundi forests and agroecosystems as well as the extent of the infestation. Methodology and Results: The survey has been conducted in all agro-ecological zones of the country in forests and the surrounding agricultural areas. After prospecting, 98 sites of about 192 hectares have been targeted based on the abundance of infested trees. In total, 15 hemi-parasitic species have been inventoried of which 11 Loranthaceae and 4 Viscaceae. The Congo-Nile crest presents the biggest diversity with 8 species while Imbo and Kumoso count only 2 species each. Ninety five (95) host species distributed in 64 genra and 37 families have been counted of which 47% are infested by Phragmanthera usuiensis . Concerning the infestation extent, the most elevated rate is found in the depression of the Kumoso while the biggest infestation intensity is found in the depression of the Northeastern Burundi. The most elevated infestation intensities are driven by three species: Phragmanthera usuiensis , Phragmanthera capitata and Agelanthus flammeus . Conclusion and application of results: The study shows a strong infestation of agricultural and forest ecosystems by the Loranthaceae. Fighting the parasites by Tufts cutting is not effective. A more efficient strategy should be documented in order to handle the plant parasites at national level. Keywords: infestation, Loranthaceae, Viscaceae, Agro-ecological zone

Sericostachys scandens , liane envahissante, represente une menace pour la diversite biologique. La presente etude a pour objectif d’evaluer l’effet des trouees, de l’altitude et de la pente sur l’abondance de S. scandens dans le Parc National de la Kibira au Burundi; et l’influence de cette liane sur la composition floristique des herbacees. L’abondance de S. scandens et des plantes herbacees a ete mesuree dans 50 trouees et 50 parcelles temoins sous couverture forestiere et soumise a une regression binomiale negative et a une analyse multivariee de la variance sur matrice de dissimilarite. La superficie des trouees a un effet positif sur l’abondance de S. scandens (z = 4,99; p < 0,0001) alors que l’altitude a un effet negatif (z = -12,63; p < 0,0001). L’invasion des stations forestieres par S. scandens modifie la composition floristique en herbacees (p= 0,01). La strategie de surveillance du PNK devrait renforcer les patrouilles pour limiter la creation de trouees d’origine anthropique. Mots cles : Trouees, invasion, liane, diversite, Parc, Burundi. English Title: Expansion of the invasive liana Sericostachys scandens Gilg & Lopr. (Amaranthaceae) in moist mountain forests: ecological determinants and impacts on herbaceous plants Sericostachys scandens, an invasive liana, represents a threat to biological diversity. The present study aimed at evaluating of the effect of gaps, altitude and slope on the abundance of S. scandensin the Kibira National Park in Burundi; and the influence of this liana on the floristic composition of herbaceous plants. The abundance of S. scandens and herbaceous plants was measured in 50 gaps and 50 control plots under forest cover and subjected to negative binomial regression and multivariate variance analysis on dissimilarity matrix. The light gap area has a positive effect on the abundance of S. scandens (z = 4.99, p < 0.0001) while the altitude has a negative effect (z = -12.63, p < 0, 0001). The invasion of forest stations by S. scandens changes the floristic composition of herbaceous plants (F = 315.026, p = 0.01). The strategy of KNP surveillance should strengthen patrols to limit the creation of anthropogenic gaps. Keywords : Gaps, invasion, liana, diversity, Park, Burundi.

There is an increasing need for monitoring schemes that help understand the evolution of the global biodiversity crisis and propose solutions for the future. Indicators, including temporal baselines, are crucial to measure the change in biodiversity over time, to evaluate progress towards its conservation and sustainable use and to set conservation priorities. They help design and monitor national and regional policies on biodiversity; they also feed into national reporting on international agreements such as the Convention on Biological Diversity and the Sustainable Development Goals. We analyse the methodological approach of five small African projects resulting from a call to promote indicator development, improve monitoring capacity and strengthen the science-policy interface in the field of biodiversity. We compared their approach to existing guidance provided by the international community, specifically the Biodiversity Indicators Partnership. To this end, we assess whether internationally recommended steps are effectively applied to national/local biodiversity monitoring in selected developing countries. We also present lessons learnt from workshop interactions between partners involved in these projects. Through our pilot projects we identified data availability and data accessibility, together with the involvement of stakeholders, as critical steps in indicator development. Moreover, there is a need for a better awareness and a wider application of the indicator concept itself. Hence, training of key actors both in the policy and science spheres is needed to operationalize indicators and ensure their continuity and sustainability. We hope that these case studies and lessons learnt can stimulate and support countries in the Global South to formulate policy-relevant biodiversity indicators. Sincere gratitude goes to A De Kesel, S Dessein, A Heughebaert, T Huyse, P Lejeune, F Malaisse and N Witters for their participation and contributions to the 2015 MRV opening workshop and to M Agarad, H de Koeijer, H Keunen, Y Loufa, F Muhashy Habiyaremye, M-L Susini Ondafe, S Van den Bossche, V Pinton, E Verheyen and K Vrancken for their input in developing and executing the MRV program. This work was supported by the Belgian Directorate-General for Development Cooperation and Humanitarian Aid (CEBioS program). Two anonymous referees are also gratefully acknowledged for their input.

The relation between landscape patterns and ecological processes forms a central hypothesis of landscape ecology. Three types of pattern analysis to assess anthropogenic impacts on landscape ecosystems and biodiversity are presented in this chapter. Firstly, the results of an analysis of Acanthaceae data in Central Africa are presented and compared with phytogeographic theories. Phytogeography data reflect the spatial variability of plant diversity, and constitute therefore a major tool in conservation policy development. We investigated if it was possible to proxy the phytogeographic classifications by the spatial distribution of Acanthaceae only. When combined with a classic landscape pattern analysis, this type of study could provide complementary information for the definition of conservation priorities. Secondly, we present an analysis of periodic vegetations in the Sudan. It can be accepted that through an understanding of the underlying mechanisms of the formation of this unique pattern geometry, the knowledge with regard to the functioning and vulnerability of these ecosystems can be deepened. Using high-resolution remote sensing imagery and digital elevation models, the relation between pattern symmetry and slope gradient was explored. In particular, slope gradients that could condition the transition between spotted and tiger bush pattern types were focused. The influence of other sources of anisotropy was also considered. Finally, a complementary approach to the calculation of landscape metrics to analyse landscape pattern is described, using the spatial processes themselves causing landscape transformation. Landscape ecologists agree that there appears to be a limited number of common spatial configurations that can result from land transformation processes. Ten processes of landscape transformation are considered: aggregation, attrition, creation, deformation, dissection, enlargement, fragmentation, perforation, shift, and shrinkage. A decision tree is presented that enables definition of the transformation process involved using patch-based data. This technique can help landscape managers to refine their description of landscape dynamics and will assist them in identifying the drivers of landscape transformation

L'objectif principal de cette étude est de décrire l'hétérogénéité spatiale de la végétation des forêts de Kigwena et de Rumonge au Burundi à travers l'identification et la caractérisation des groupements végétaux en présence. Cette étude met également en évidence l'organisation sociologique de la végétation des deux forêts et contribue à élargir les connaissances phytosociologiques qui restent encore fragmentaires sur la végétation des écosystèmes forestiers du Burundi. Les analyses sont basées sur les données issues de 23 relevés phytosociologiques réalisés à travers les faciès de la forêt de Kigwena et de mesures du diamètre à hauteur de poitrine dans 12 transects tracés dans la forêt de Rumonge. Quatre et trois groupements végétaux ont été respectivement individualisés, caractérisés et classés dans les taxons supérieurs (classe, ordre et alliance). Dans la forêt de Kigwena, la typologie de la végétation obéit à un gradient d'humidité et d'anthropisation et l'effet lisière marque nettement la diversité biologique des groupements végétaux. Mais, dans la forêt de Rumonge, l'hétérogénéité des faciès de végétation correspondrait aux phénomènes de dégradation localisée dans un même fond floristique.