Assessing the role of dispersed floralresources for managed bees in providingsupporting ecosystem services for croppollination

Most pollination ecosystem services studies have focussed on wild pollinators and their dependence on natural floral resources adjacent to crop fields. However, managed pollinators depend on a mixture of floral resources that are spatially separated from the crop field. Here, we consider the supporting role these resources play as an ecosystem services provider to quantify the use and availability of floral resources, and to estimate their relative contribution to support pollination services of managed honeybees. Beekeepers supplying pollination services to the Western Cape deciduous fruit industry were interviewed to obtain information on their use of floral resources. For 120 apiary sites, we also analysed floral resources within a two km radius of each site based on geographic data. The relative availability of floral resources at sites was compared to regional availability. The relative contribution of floral resources-types to sustain managed honeybees was estimated. Beekeepers showed a strong preference for eucalypts and canola. Beekeepers selectively placed more hives at sites with eucalypt and canola and less with natural vegetation. However, at the landscape-scale, eucalypt was the least available resource, whereas natural vegetation was most common. Based on analysis of apiary sites, we estimated that 700,818 ha of natural vegetation, 73,910 ha of canola fields, and 10,485 ha of eucalypt are used to support the managed honeybee industry in the Western Cape. Whereas the Cape managed honeybee system uses a bee native to the region, alien plant species appear disproportionately important among the floral resources being exploited. We suggest that an integrated approach, including evidence from interview and landscape data, and fine-scale biological data is needed to study floral resources supporting managed honeybees

Predictive habitat models integrating anthropic pressures to aid conservation of a rare species on Reunion island, the Mascarene petrel

Conservation planning requires the identification of habitat that may support focal species, and an assessment of how to prioritise lands to protect sustainable populations. Because conservation plans often guide the allocation of limited resources in the face of habitat loss, there is little room for error in the prioritisation process. However, incomplete information on the distributions of species and habitats makes prioritisation an enormous challenge, particularly if surveys cannot be conducted due to land inaccessibility or other constraints. The use of predictive habitat distribution models by land managers in the conservation management of threatened species is therefore increasing. Reunion Island (western Indian Ocean) is one of the few islands at global scale holding two endemic species of petrels, the Barau's Petrel (Pterodroma baraui), and the Mascarene Petrel (Pseudobulweria aterrima), both of which are poorly known and endangered. The principal threats to both species are introduced mammalian predators (rats and feral cats) and light pollution. In this study, we focused on the very rare Mascarene petrel whose remained mysterious for 160 years. Thanks to the recent discovery of breeding sites in 2016, it is vital, to face conservation urgency, to quickly identify all potential breeding areas and engage actions at a broader scale. Thus, we used environmental parameters mixed with anthropic pressures (predators density and level of invasive plants) to investigate and model the distribution of suitable habitat of this rare and endemic species. Predictive distribution maps revealed habitat refuges suggesting a high sensitivity of the species to anthropogenic pressures. This approach is very helpful for long-term management to 1) identify priority conservation areas, 2) design concrete actions to be implemented according to the environmental / anthropic characteristics of the habitat

The meaning and practice of stewardship in South Africa

Stewardship offers a means of addressing social-ecological sustainability challenges, from the local to the global level. The concept of stewardship has had various meanings attached to it over time, and the links between the theory and practice of stewardship are not well understood. We sought to characterise the practice of stewardship in South Africa, to better understand the relationship between theory and practice. We found that practitioners' understandings of stewardship coalesce around two core notions: the idea of stewardship as 'responsible use and care' of nature, and stewardship as a 'balancing act' between stewards' use of natural resources for agricultural production and their responsibility to protect and manage the wider ecosystem. Stewardship practice in South Africa is strongly influenced by the biodiversity stewardship tool; however, many practitioners are integrating biodiversity stewardship with other approaches. These emerging social-ecological stewardship initiatives operate at landscape-level and work towards integrated social and ecological stewardship outcomes, by facilitating collaboration among diverse stakeholders. Further research is needed to better understand what is required to support these integrated, collaborative and cross-sectoral initiatives. Policy mechanisms that facilitate integrated place-based stewardship practice can contribute to expanding the practice of biodiversity stewardship in South Africa

Collaborative stewardship in multifunctional landscapes: Toward relational, pluralistic approaches

Landscape stewardship offers a means to put social-ecological approaches to stewardship into practice. The growing interest in landscape stewardship has led to a focus on multistakeholder collaboration. Although there is a significant body of literature on collaborative management and governance of natural resources, the particular challenges posed by multifunctional landscapes, in which there are often contested interests, require closer attention. We present a case study from South Africa to investigate how collaborative stewardship can be fostered in contested multifunctional landscapes. We conducted this research through an engaged transdisciplinary research partnership in which we integrated social-ecological practitioner and academic knowledge to gain an in-depth understanding of the challenges of fostering collaboration. We identified five overarching factors that influence collaboration: contextual, institutional, social-relational, individual, and political-historical. Collaborative stewardship approaches focused on the development of formal governance institutions appear to be most successful if enabling individual and social-relational conditions are in place. Our case study, characterized by high social diversity, inequity, and contestation, suggests that consensus-driven approaches to collaboration are unlikely to result in equitable and sustainable landscape stewardship in such contexts. We therefore suggest an approach that focuses on enhancing individual and social-relational enablers. Moreover, we propose a bottom-up patchwork approach to collaborative stewardship premised on the notion of pluralism. This would focus on building new interpersonal relationships and collaborative capacity through small collective actions. Taking a relational, pluralistic approach to fostering collaborative stewardship is particularly important in contested, socially heterogeneous landscapes. Drawing on our study and the literature, we propose guiding principles for implementing relational, pluralistic approaches to collaborative stewardship and suggest future research directions for supporting such approaches

Developing long-term monitoring of natural areas for a Unesco world heritage site: study case of la Reunion

La Réunion island, in the Mascarenes, has been recognized as a World Heritage site for its Piton, Cirques and Remparts since 2010. The site, coinciding with the core zone of La Réunion National Park, represents 100000 ha, equivalent to 40 % of the island. These dramatic landscapes of rugged terrain, impressive escarpments, forested gorges are dominated by three cliff-rimmed cirques and two volcanoes ― a dormant massif forming the highest peak, Piton des Neiges (3069 m), and in the eastern part of the island lies the very active volcano, the Piton de la Fournaise (2632 m). The island harbours a wide variety of natural habitats (tropical montane cloud forests, subalpine shrublands, lowland forests, dry forest…), now all remnant in the Mascarene archipelago, that host high levels of endemism for both flora and fauna. Thereby, La Réunion is the most significant contributor towards conservation of terrestrial biodiversity in the Mascarene islands. The Divines project (FEDER) aims at developing innovative methods for characterizing and monitoring terrestrial biodiversity in the long term for conservation managers to ensure the protection of this world heritage site. In this poster, a description of the goals, actions and preliminary results of the DIVINES project will be described from gene to ecosystem levels

Pollination ecosystem services in South African agricultural systems

Insect pollinators, both managed and wild, have become a focus of global scientific, political and media attention because of their apparent decline and the perceived impact of this decline on crop production. Crop pollination by insects is an essential ecosystem service that increases the yield and quality of approximately 35% of crops worldwide. Pollinator declines are a consequence of multiple environmental pressures, e.g. habitat transformation and fragmentation, loss of floral resources, pesticides, pests and diseases, and climate change. Similar environmental pressures are faced in South Africa where there is a high demand for pollination services. In this paper, we synthesise data on the importance of different pollinators as a basis for services to South African crops and on the status of managed honeybees. We also focus on insect pollination services for the Western Cape deciduous fruit industry, which is worth ZAR9800 million per year and is heavily reliant on pollination services from managed honeybees. We discuss landscape and regional level floral resources needed to maintain sufficient numbers of managed honeybee colonies. In summary, the available literature shows a lack of data on diversity and abundance of crop pollinators, and a lack of long-term data to assess declines. We highlight key areas that require research in South Africa and emphasise the critical role of floral resource availability at the landscape and regional scale to sustain pollinators. We conclude that understanding the dynamics of how floral resources are used will help inform how landscapes could be better managed in order to provide long-term sustainable pollination services

Implementation of a sampling protocol for the delimitation of ZNIEF in Grande Comore island

Comoros archipelago is among the 20 island states within biodiversity hot spots, in terms of global conservation priorities. Grande Comore is the largest and well-preserved island in the Comoros archipelago. Taking into account nature and the various natural and anthropogenic pressures, it is im-portant to promote a management plan that would guide future conservation issues for the island's flora and habitats. Nevertheless, considering the fact that little data exists for the Comoros, it is necessary to develop a methodology that is both rapid and repeatable, in order to delimit the ZNIEFF (Natural Zones of Ecological, Faunistic and Floristic Interest) in Grande Comore Island. Given the urgent need to define a conservation plan in the Comoros, we have focused this study on the remnant forests of La Grille, on the northern side of Grande Comore Island, a choice motivated by the accessibility of this site and the size of its massif (300 km2). We have delineated the board units of vegetation by ortho-photography using QGIS software and existing data. This experimentation will be followed by a field survey using a ZNIEFF-type inventory, as well as a verification of the delimited areas based on the data recorded on the study site. It will then provide an approach on the state of conservation of remnant forests, the different types of pressures within natural and semi-natural habitats and the extent of existing threats, including invasion by exotic species. The approach defines areas of ecological interest and provides a management framework for prioritizing habitat conservation choices. It will thus serve as a decision-making support for future biodiversity conservation issues in the Comoros

Rapid assessment of plant invasions in natural and semi-natural forest habitats in Grande Comore island

Comoros archipelago is a biodiversity hot spot characterized by a relatively dynamic land use change. Natural forests in these islands are exposed to serious anthropogenic-induced threats with severe impacts on the structure of biodiversity. Among these, biological invasions by exotic plants remain a serious problem that hinders the conservation of native vegetation in Comoros. It is therefore necessary to establish management priorities for these forest remnants, but reference data barely exists on the invasion level of forest habitats by plants in the archipelago. In this study, we focus on the island of Grande Comore and specifically address the two following questions: (i) which plant species are the most invasive and (ii) what are the invasion level of different forest habitats? This study has been conducted on exotic woody plants. Surveys were targeted at lowland and sub-mountain forests on 44 transects of 150 X 10 m from 23 to 1047 asl. Transects were divided in sections of 30 m to facilitate the recording of species invasion levels, habitat types and land use. Sampling was carried out on individuals whose size was superior to 1 m. Major invasive plants in natural and semi-natural forests include Psidium cattleianum, Clidemia hirta, Furcraea foetida, Rubus rosifolius and Syzygium jambos. In term of habitats, lowland forests have been cleared and replaced by plantations (coconut and / or fruit trees). The sub-montain forests dominated by native species of Nuxia, Ocotea and Tambourissa are typically uninvaded in their canopy whereas sub-mountain forests dominated by Weinmannia is invaded in the understory and the canopy. The results obtained represent the first assessment of plant invasion in forests on Grande Comore. In order to define management priorities, it is necessary to expand these surveys. Results of this study will contribute to improve decision-making for the National Park program in Comoros

Priorisation spatiale des actions de gestion des plantes exotiques envahissantes : une étape-clé de la conservation à long terme des milieux naturels à la Réunion. Version 1

Contexte : Les invasions biologiques constituent une des menaces principales de l'érosion de la biodiversité dans le monde et notamment sur l'île de La Réunion. Cette étude a pour but de coordonner et de spatialiser les enjeux de conservation, en rassemblant toutes les données existantes pour établir un état des lieux spatialisé à une échelle utile aux gestionnaires afin de prioriser les actions de gestion des plantes exotiques envahissantes. Une approche de priorisation spatiale basée sur un algorithme d'aide à la décision a été utilisée. Cette approche est participative et co-développée avec les gestionnaires afin de répondre à une demande du département de La Réunion. Approche : Nous avons rassemblés un ensemble solide de données quant à la distribution de la faune et de la flore indigènes, la répartition des habitats et leur niveau d'invasion. L'ensemble de ces données ont été insérées au sein d'un logiciel d'aide à la décision, Zonation, permettant l'identification des enjeux de conservation. L'utilisation de ce logiciel permet l'identification de priorités objectives et basées sur des concepts clés. Ainsi, les priorités identifiées mettent en avant les zones peu envahies, les habitats et espèces rares et sont représentatives de l'ensemble de la biodiversité. Une fois les enjeux de conservation identifiés, il est possible de définir les priorités d'actions de lutte contre les plantes exotiques. Pour cela, trois critères opérationnels ont été utilisés : l'accessibilité de la zone, les priorités d'intervention et l'historique des chantiers. Résultats : Ces analyses nous ont permis d'identifier 58 500 ha d'enjeux de conservation parmi lesquels 30% sont considérés comme non envahis, ce qui implique des actions de surveillance. A l'inverse, 53 714 ha de zones potentielles d'intervention ont été identifiées. Parmi ces zones, 4392 ha sont considérés comme étant de forte priorité. Trois résultats principaux y sont présentés : la carte du degré d'invasion, les enjeux de conservation et les priorités d'actions de lutte. Les données spatiales sont téléchargeables sur le site du GEIR : https://www.especesinvasives.re/en-pratique/documents-et-outils/article/documents-et-outil

Forestry plantations as a pathway for invasive alien plants in the National Park at Réunion island

Identifying pathways of introduction remains a major priority to prevent future plant invasions into natural areas. In this study, we assessed whether forestry plantations favor alien plant dissemination into the National Park of Reunion. Results showed significant decrease in the percentage of alien plant biomass from the forestry plantations to the undisturbed areas. At one site, a significant difference was also found for the mean alien species number and the mean alien plant abundance. In both sites, numerous alien species were present in the understorey of Cryptomeria plantations only, with some already escaping and occurring at the entrance of the National Park. This study recommends strengthening early detection and rapid response of alien plants and suggests alternative management approaches in forestry plantations, including the use of community-based restoration programmes.Une des priorités pour contrôler les futures invasions floristiques est d’identifier les voies d’introduction aux abords des aires naturelles. Dans cette étude, nous avons testé si les forêts cultivées peuvent favoriser l’envahissement par les plantes exotiques à l’intérieur du Parc national de la Réunion. Les résultats montrent une diminution significative du pourcentage de la biomasse végétale des plantes exotiques des forêts cultivées vers le milieu naturel. Les différences sont également significatives au niveau d’un des deux sites étudiés concernant les moyennes du nombre de plantes exotiques et de la somme de l’abondance des plantes. Dans les deux cas, de nombreuses espèces sont présentes seulement en sous-bois de forêts cultivées ou également à l’entrée du Parc national. Cette étude préconise de renforcer les actions de détection précoce et de réponse rapide. Les auteurs proposent également la mise en place de méthodes de gestion alternatives de ces habitats incluant une approche participative de la population dans des programmes de restauration