Assessing global tendencies and impacts of conditional payments for environmental services (PES) programs is challenging because of their heterogeneity, and scarcity of comparative studies. This meta-study systematizes 55 PES schemes worldwide in a quantitative database. Using categorical principal component analysis to highlight clustering patterns, we reconfirm frequently hypothesized differences between public and private PES schemes, but also identify diverging patterns between commercial and non-commercial private PES vis-à-vis their service focus, area size, and market orientation. When do these PES schemes likely achieve significant environmental additionality? Using binary logistical regression, we find additionality to be positively influenced by three theoretically recommended PES ‘best design’ features: spatial targeting, payment differentiation, and strong conditionality, alongside some contextual controls (activity paid for and implementation time elapsed). Our results thus stress the preeminence of customized design over operational characteristics when assessing what determines the outcomes of PES implementation.

Climate change is posing new challenges to conservation because management policies on protected coral reefs are less eVective than they were before the current ecosystem degradation. Coral reefs, the most diverse and complex marine ecosystem provide economic services for millions, but are seriously threatened worldwide because reef-building corals are experiencing bleaching phenomena and a steady decline in abundance. The resources of a Marine Protected Area (MPA) in Cartagena, Colombia, are in constant decline, despite a current management plan and on-site staV, urging new conservation actions. A multidisciplinary team gathered to evaluate management eVectiveness including biophysical, socioeconomic and governance indicators. Coral cover and Wsh diversity and abundance were low both inside and outside the MPA, which suggests a limited eYciency of management. Currently, the MPA is a reef with low coral cover and high algae cover as well as large dead coral areas, which are generally signs of highly degraded reef habitats. Live coral cover in the MPA was represented by pioneer coral species such as Agaricia tenuifolia and Porites astreoides. Nonetheless, 35% of the scleractinian species sampled in the area harbored more than one zooxanthellae symbiont, which suggests potential resistance and resilience against coral bleaching. Maintenance of trophic structure and functional diversity is an important endeavor that should be a priority for management in order to allow ecosystem resilience. Social and governance indicators showed low-income levels and few opportunities for communities living in and around the park, low governability, Biodivers Conserv (2009) 18:935-956 1 C weak communication among stakeholders and with authorities at diVerent levels. As a result, problems related to over exploitation of resources were commonplace in the MPA. These results reXect low adaptive capacity of communities to comply with restrictive conservation rules, showing that establishment of a protected area is a necessary but insuYcient condition to guarantee conservation goals. Ignoring the role of local communities only will exacerbate the problems associated with natural resources. Involvement of communities in strategic ecosystems management appears to be a requisite to improve eVectiveness of protected areas, and participatory strategies, such as co-management, oVer opportunities to improve governability while letting communities adapt to MPA needs.

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In developing countries, informal waste-pickers (known as scavengers) play an important role in solid waste management systems, acting in a parallel way to formal waste collection and disposal agents. Scavengers collect, from the streets, dumpsites, or landfills, re-usable and recyclable material that can be reincorporated into the economy's production process. Despite the benefits that they generate to society, waste-pickers are ignored when waste management policies are formulated. The purpose of this paper is to integrate the role of scavengers in a dynamic model of production, consumption, and recovery, and to show that, in an economy producing solid waste, efficiency can be reached using a set of specific and complementary policies: a tax on virgin materials use, a tax on consumption and disposal, and a subsidy to the recovery of material. A numerical simulation is performed to evaluate the impact of these policies on landfill lifetime and natural resource stocks. A discussion on the implementation of these instruments is also included.

In view of current worldwide coral reef decline, and the shortcomings of traditional top-down management schemes of Marine Protected Areas (MPAs), decision makers and scientists face the important challenge of developing new approaches to generate effective conservation strategies. This study evaluates MPAs as linked social-ecological systems (SES) to inform better management by calculating indices for ecological health, social adaptive capacity, and the impact intensity of overfishing, pollution, and tourism. A series of ecological and socioeconomic indicators are used to estimate these indices and determine relevant conservation strategies in two protected areas in the Colombian Caribbean. Results reveal a precarious situation of high impact intensity combined with low ecological health and adaptive capacity. This study provides further evidence supporting the need for reconciliation of SES and a framework by which decision makers can assess priorities to increase MPA effectiveness. We highlight the need for system reorganization and recommend bottom-up comanagement schemes as a priority strategy to strengthen adaptive capacity.