Designing Large-Scale Conservation Corridors for Pattern and Process MATHIEU ROUGET, ∗ RICHARD M. COWLING,† AMANDA T. LOMBARD,† ANDREW T. KNIGHT,† AND GRAHAM I.H. KERLEY‡ ∗ Kirstenbosch Research Centre, South African National Biodiversity Institute, Claremont 7735, South Africa and Botany Department, University of Cape Town, Rondebosch 7701, South Africa, email rouget@sanbi.org †Department of Botany and Terrestrial Ecology Research Unit, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031, South Africa ‡Terrestrial Ecology Research Unit and Department of Zoology, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031, South Africa Abstract: A major challenge for conservation assessments is to identify priority areas that incorporate biolog- ical patterns and processes. Because large-scale processes are mostly oriented along environmental gradients, we propose to accommodate them by designing regional-scale corridors to capture these gradients. Based on systematic conservation planning principles such as representation and persistence, we identified large tracts of untransformed land (i.e., conservation corridors) for conservation that would achieve biodiversity targets for pattern and process in the Subtropical Thicket Biome of South Africa. We combined least-cost path analysis with a target-driven algorithm to identify the best option for capturing key environmental gradients while considering biodiversity targets and conservation opportunities and constraints. We identified seven conser- vation corridors on the basis of subtropical thicket representation, habitat transformation and degradation, wildlife suitability, irreplaceability of vegetation types, protected area networks, and future land-use pressures. These conservation corridors covered 21.1% of the planning region (ranging from 600 to 5200 km 2 ) and successfully achieved targets for biological processes and to a lesser extent for vegetation types. The corridors we identified are intended to promote the persistence of ecological processes (gradients and fixed processes) and fulfill half of the biodiversity pattern target. We compared the conservation corridors with a simplified corridor design consisting of a fixed-width buffer along major rivers. Conservation corridors outperformed river buffers in seven out of eight criteria. Our corridor design can provide a tool for quantifying trade-offs between various criteria (biodiversity pattern and process, implementation constraints and opportunities). A land-use management model was developed to facilitate implementation of conservation actions within these corridors. Key Words: biological processes, conservation implementation, conservation planning, landscape connectivity, landscape linkages Dise˜ no de Corredores de Conservaci´ on de Gran Escala para Patrones y Procesos Resumen: La identificaci´ on de ´ areas prioritarias que incorporen patrones y procesos biol´ ogicos es uno de los mayores retos de las evaluaciones de acciones de conservaci´ on. Debido a que la mayor´ ıa de los procesos a gran escala est´ an orientado a lo largos de gradientes ambientales, proponemos acomodarlos mediante el dise˜ no de el dise˜ no de corredores de escala regional para capturar esos gradientes. Con base en principios de planificaci´ on de conservaci´ on sistem´ aticos, tales como la representaci´ on y la persistencia, identificamos grandes extensiones de terrenos no transformados (i.e., corredores de conservaci´ on) para conservar patrones y procesos en el Bioma de Matorral Subtropical de ´ Africa del Sur. Combinamos el an´ alisis de la trayectoria de menor costo con un algoritmo dirigido a un objetivo para identificar la mejor opci´ on para capturar gradientes Paper submitted September 16, 2004; revised manuscript accepted May 11, 2005. 549 Conservation Biology Volume 20, No. 2, 549–561 C 2006 Society for Conservation Biology DOI: 10.1111/j.1523-1739.2006.00297.x