Mathieu Rouget

An operational model for mainstreaming ecosystem services for implementation

Research on ecosystem services has grown markedly in recent years. However, few studies are embedded in a social process designed to ensure effective management of ecosystem services. Most research has focused only on biophysical and valuation assessments of putative services. As a mission-oriented discipline, ecosystem service research should be user-inspired and user-useful, which will require that researchers respond to stakeholder needs from the outset and collaborate with them in strategy development and implementation. Here we provide a pragmatic operational model for achieving the safeguarding of ecosystem services. The model comprises three phases: assessment, planning, and management. Outcomes of social, biophysical, and valuation assessments are used to identify opportunities and constraints for implementation. The latter then are transformed into user-friendly products to identify, with stakeholders, strategic objectives for implementation (the planning phase). The management phase undertakes and coordinates actions that achieve the protection of ecosystem services and ensure the flow of these services to beneficiaries. This outcome is achieved via mainstreaming, or incorporating the safeguarding of ecosystem services into the policies and practices of sectors that deal with land- and water-use planning. Management needs to be adaptive and should be institutionalized in a suite of learning organizations that are representative of the sectors that are concerned with decision-making and planning. By following the phases of our operational model, projects for safeguarding ecosystem services are likely to empower stakeholders to implement effective on-the-ground management that will achieve resilience of the corresponding social-ecological systems.

A conservation plan for a global biodiversity hotspot: the Cape Floristic Region, South Africa

We produced a conservation plan that achieved conservation targets for biodiversity pattern and process in the species- and endemic-rich Cape Floristic Region of South Africa. Features given quantitative conservation targets were land classes, localities of Proteaceae and selected vertebrate (freshwater fish, amphibians and reptiles) species, population sizes for medium- and large-sized mammals, and six types of spatial surrogates for ecological and evolutionary processes. The plan was developed in several stages using C-Plan, a decision support system linked to a geographic information system. Accepting the existing reserve system as part of the plan, we first selected spatially fixed surrogates for biodiversity processes; then we included those planning units that were essential for achieving targets for land classes, Proteaceae and vertebrate species; next we included areas required to accommodate population and design targets for large and medium-sized mammals; we then selected planning units required to conserve entire upland–lowland and macroclimatic gradients; and finally we resolved the options for achieving remaining targets while also consolidating the design of conservation areas. The result was a system of conservation areas, requiring, in addition to the existing reserve system, 52% of the remaining extant habitat in the planning domain, as well as restorable habitat, that will promote the persistence and continued diversification of much of the region’s biota in the face of ongoing habitat loss and climate change. After describing the planning process, we discuss implementation priorities in relation to conservation value and vulnerability to habitat loss, as well as socio-economic, political and institutional constraints and opportunities. # 2003 Elsevier Science Ltd. All rights reserved.

Formulating conservation targets for biodiversity pattern and process in the Cape Floristic Region, South Africa

The Cape Floristic Region of South Africa is a global biodiversity hotspot. In 1998, a process of conservation planning began in the region that required quantitative targets for biodiversity. We combined new information and previously available data sets on biodiversity pattern and process to formulate targets for five groups of features: 102 broad habitat units (land types); locality records for 364 plant species in the family Proteaceae; locality records for 345 species of reptiles, amphibians and freshwater fish; estimated distributions and densities of 41 species of large and medium-sized mammals; and six types of spatial surrogates for ecological and evolutionary processes. We discuss our approach to formulating quantitative targets in the context of the general role of targets in conservation planning, the inadequacy of commonly used standard targets such as 10% of features or whole regions, and the uncertainties around setting targets for land types. We then describe our reasoning and methods for analysing data and identifying targets for each group of features. Our targets are not theoretical-they have been used to develop a regional conservation plan for which implementation is underway. Our targets are, however, provisional. Like any other conservation targets, they are estimates of the requirements for persistence of a regions biodiversity made within the constraints of limited information. We expect them to be improved in future reviews of appropriate targets for the Cape Floristic Region and elsewhere. Crown Copyright (C) 2003 Published by Elsevier Science Ltd. All rights reserved.

Inferring Process from Pattern in Plant Invasions: A Semimechanistic Model Incorporating Propagule Pressure and Environmental Factors

Propagule pressure is intuitively a key factor in biological invasions: increased availability of propagules increases the chances of establishment, persistence, naturalization, and invasion. The role of propagule pressure relative to disturbance and various environmental factors is, however, difficult to quantify. We explored the relative importance of factors driving invasions using detailed data on the distribution and percentage cover of alien tree species on South Africa’s Agulhas Plain (2,160 km2). Classification trees based on geology, climate, land use, and topography adequately explained distribution but not abundance (canopy cover) of three widespread invasive species (Acacia cyclops, Acacia saligna, and Pinus pinaster). A semimechanistic model was then developed to quantify the roles of propagule pressure and environmental heterogeneity in structuring invasion patterns. The intensity of propagule pressure (approximated by the distance from putative invasion foci) was a much better predictor of canopy cover than any environmental factor that was considered. The influence of environmental factors was then assessed on the residuals of the first model to determine how propagule pressure interacts with environmental factors. The mediating effect of environmental factors was species specific. Models combining propagule pressure and environmental factors successfully predicted more than 70% of the variation in canopy cover for each species.

Current patterns of habitat transformation and future threats to biodiversity in terrestrial ecosystems of the Cape Floristic Region, South Africa

The formulation of an effective strategic plan for biodiversity conservation in the Cape Floristic Region (CFR) requires an assessment of the current situation with regard to habitat transformation, and an explicit framework for predicting the likelihood of remaining habitat (i.e. that potentially available for conservation) being transformed. This paper presents the results of a detailed assessment of the current and future extent of three important factors that threaten biodiversity in the CFR: cultivation for intensive agriculture (including commercial forestry plantations), urbanisation, and stands of invasive (self-sown) alien trees and shrubs. The extent of habitat transformation was mapped at the scale of 1:250,000, using primarily satellite imagery. We compared models derived from a rule-based approach relying on expert knowledge and a regression-tree technique to identify other areas likely to be affected by these factors in future. Cultivation for agriculture has transformed 25.9% of the CFR and dense stands of woody alien plants and urban areas each cover 1.6%. Both models predict that at least 30% of the currently remaining natural vegetation could be transformed within 20 years. There was an overall accuracy of 73% between both models although significant differences were found for some habitat types. Spatial predictions of future agriculture threats derived from the rule-based approach were overestimated relative to the statistical approach, whereas future alien spread was underestimated. Threat assessment was used to derive conservation targets for subsequent stages of conservation planning for the CFR. The importance of integrating vulnerability knowledge into conservation planning is discussed. The choice of vulnerability analysis (future habitat degradation and/or impact on biological entities) and methods will depend on the complexity of the threatening processes and the availability of spatial data.

INTERACTIONS BETWEEN ENVIRONMENT, SPECIES TRAITS, AND HUMAN USES DESCRIBE PATTERNS OF PLANT INVASIONS

Although invasive alien species (IAS) are a major threat to biodiversity, human health, and economy, our understanding of the factors controlling their distribution and abundance is limited. Here, we determine how environmental factors, land use, life-history traits of the invaders, residence time, origin, and human usage interact to shape the spatial pattern of invasive alien plant species in South Africa. Relationships between the environmental factors and the extrinsic and intrinsic attributes of species were investigated using RLQ analysis, a multivariate method for relating a species-attribute table to an environmental table by way of a species presence/absence table. We then clustered species according to their position on the RLQ axes, and tested these groups for phylogenetic independence. The first three axes of the RLQ explained 99% of the variation and were strongly related to the species attributes. The clustering showed that, after accounting for environmental factors, the spatial pattern of IAS in South Africa was driven by human uses, life forms, and reproductive traits. The seven clusters of species strongly reflected geographical distribution, but also intrinsic species attributes and patterns of human use. Two of the clusters, centered on the genera Acacia and Opuntia, were phylogenetically non-independent. The remaining clusters comprised species of diverse taxonomic affinities, but sharing traits facilitating invasion in particular habitats. This information is useful for assessing the extent to which the potential spread of recent introductions can be predicted by considering the interaction of their biological attributes, region of origin, and human use.

The current configuration of protected areas in the Cape Floristic Region, South Africa—reservation bias and representation of biodiversity patterns and processes

Abstract The formulation of a strategic plan for the conservation of terrestrial biodiversity in the Cape Floristic Region (CFR; 87,892 km2) requires an objective and spatially explicit assessment of the representativeness of major habitat categories (surrogates for biodiversity) currently under protection. A GIS layer of statutory and non-statutory conservation areas was used, along with layers of many biological and physical features, to explore the configuration of conserved areas relative to key biological and physical indicators. Three analyses were performed. (1) Recursive partitioning, a classification-tree analysis technique, was used to contrast features of protected areas with non-protected areas. (2) The conservation status of 16 primary and 88 secondary Broad Habitat Units (BHUs; derived on the basis of topography, geology, homogeneous climatic zones, and floristic composition) was assessed in terms of prescribed conservation targets. (3) The extent to which protected areas are able to sustain ecological and evolutionary processes was explored by assessing the extent of spatial components of these processes for all conservation areas. About 20% of the CFR is protected in some form of conservation area, mostly concentrated on sandstone substrates, and areas with high altitude and steep slopes. The reservation bias towards upland areas has seriously constrained representation of biodiversity pattern and processes. Most of the habitat diversity is poorly represented in the current conservation area system with only 9% of the remaining primary BHUs in the lowlands conserved. However, almost 50% of the Mountain Fynbos Complex is conserved (largely exceeding its conservation target). Spatial components of the ecological processes identified are poorly captured by the conservation area network although faunal and floral migration is possible in the uplands due to the strong spatial connectivity of the protected network.

Establishing IUCN red list criteria for threatened ecosystems

Abstract The potential for conservation of individual species has been greatly advanced by the International Union for Conservation of Natures (IUCN) development of objective, repeatable, and transparent criteria for assessing extinction risk that explicitly separate risk assessment from priority setting. At the IV World Conservation Congress in 2008, the process began to develop and implement comparable global standards for ecosystems. A working group established by the IUCN has begun formulating a system of quantitative categories and criteria, analogous to those used for species, for assigning levels of threat to ecosystems at local, regional, and global levels. A final system will require definitions of ecosystems; quantification of ecosystem status; identification of the stages of degradation and loss of ecosystems; proxy measures of risk (criteria); classification thresholds for these criteria; and standardized methods for performing assessments. The system will need to reflect the degree and rate of change in an ecosystems extent, composition, structure, and function, and have its conceptual roots in ecological theory and empirical research. On the basis of these requirements and the hypothesis that ecosystem risk is a function of the risk of its component species, we propose a set of four criteria: recent declines in distribution or ecological function, historical total loss in distribution or ecological function, small distribution combined with decline, or very small distribution. Most work has focused on terrestrial ecosystems, but comparable thresholds and criteria for freshwater and marine ecosystems are also needed. These are the first steps in an international consultation process that will lead to a unified proposal to be presented at the next World Conservation Congress in 2012. Establecimiento de Criterios para la Lista Roja de UICN de Ecosistemas Amenazados Resumen El potencial para la conservación de muchas especies ha avanzado enormemente porque la Unión Internacional para la Conservación de la Naturaleza (UICN) ha desarrollado criterios objetivos, repetibles y transparentes para evaluar el riesgo de extinción que explícitamente separa la evaluación de riesgo de la definición de prioridades. En el IV Congreso Mundial de Conservación en 2008, el proceso comenzó a desarrollar e implementar estándares globales comparables para ecosistemas. Un grupo de trabajo establecido por la UICN ha formulado un sistema inicial de categorías y criterios cuantitativos, análogos a los utilizados para especies, para asignar niveles de amenaza a ecosistemas a niveles local, regional y global. Un sistema final requerirá de definiciones de ecosistemas; cuantificación del estatus de ecosistemas; identificación de las etapas de degradación y pérdida de los ecosistemas; medidas de riesgo (criterios) alternativas; umbrales de clasificación para esos criterios y métodos estandarizados para la realización de evaluaciones. El sistema deberá reflejar el nivel y tasa de cambio en la extensión, composición, estructura y funcionamiento de un ecosistema, y tener sus raíces conceptuales en la teoría ecológica y la investigación empírica. Sobre la base de esos requerimientos y la hipótesis de que el riesgo del ecosistema es una función del riesgo de las especies que lo componen, proponemos un conjunto de 4 criterios: declinaciones recientes en la distribución o funcionamiento ecológica, pérdida total histórica en la distribución o funcionamiento ecológico, distribución pequeña combinada con declinación, o distribución muy pequeña. La mayor parte del trabajo se ha concentrado en ecosistemas terrestres, pero también se requieren umbrales y criterios comparables para ecosistemas dulceacuícolas y marinos. Estos son los primeros pasos de un proceso de consulta internacional que llevará a una propuesta unificada que será presentada en el próximo Congreso Mundial de Conservación en 2012.

An Assessment of Habitat Diversity and Transformation on La Réunion Island (Mascarene Islands, Indian Ocean) as a Basis for Identifying Broad-scale Conservation Priorities

Most natural habitat in the Mascarene Islands (Mauritius, La Réunion and Rodrigues) has been transformed. Although urbanisation, agriculture and alien plant invasions have transformed large areas in La Réunion, the island has by far the greatest area of intact habitats in the Mascarenes, but remaining natural areas are under threat. We propose a protocol for defining a system of habitat types and for using these to provide a preliminary assessment of conservation priorities for La Réunion. The protocol draws on existing data and expert knowledge to map habitat types, assesses the extent of habitat transformation, and quantifies heterogeneity between habitat types based on climate, topography and geology. The pattern of habitat transformation was uneven among the nineteen habitat types identified. While three habitats have lost > 95% of their original area, four still retain> 80% of their original extent. Habitat types could be grouped into the following categories: (i) transformed habitats with low levels of plant endemism, (ii) habitats confined to homogenous geology with high levels of plantendemism, and (iii) species-rich heterogeneous habitats on diverse geological types. Priority habitats were also identified using municipalities as a basis for implementation. Urgent action is required for several habitat types where a large part of the original extent has been transformed. Three municipalities which contain more than 10 habitat types should receive conservation priority. The analysis provides the basis for setting conservation priorities in La Réunion at the regional and local scale. Implications of the results are discussed with reference to requirements for finer-scale conservation planning.

Predicting invasion dynamics of four alien Pinus species in a highly fragmented semi-arid shrubland in South Africa

This study explored the determinants of spread of four alien Pinus species and the ability of models to predict invasion dynamics in a complex fragmented landscape. The role of environmental factors, natural and anthropogenic disturbance in relation to invasion history was assessed for different stages in the invasion process using a Geographic Information System. Pines escaped from plantations over the past 30 years and spread into the natural semi-arid shrubland (renosterveld). The pattern of spread was compared with a simulated random distribution using two different techniques, a standard logistic regression, and a new recursive modelling approach (Formal Inference-based Recursive Modelling; FIRM). FIRM analysis improved the accuracy of predictions and revealed interactive effects of variables hidden by the logistic regression analysis. More than 80% of isolated pine individuals were found in 20% of the habitat classified as suitable by the models. Soil pH was the most important predictor for the distribution of isolated trees, whereas the establishment of dense pine stands was largely determined by fire history. Differences in invasive behaviour could be explained by species attributes such as limited dispersal for P. canariensis, and better drought-tolerance for P. halepensis. Sixty-five percent of the current pine distribution was accurately predicted by the spatial distribution of the first trees to have invaded. Such models could be used to predict potential spread of invasive plants and gain a better understanding of the main factors driving the invasion process. However, the spread of invasive species in fragmented landscapes, strongly modified by human activities, is very complicated, and the spread remains difficult to predict in the long term. The dynamics of invasion are discussed in relation to changes in land use and disturbance regime.