Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
Conserv Biol ; 38(2): e14225, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38328897

RESUMEN

Private land protection is an important and growing tool to address biodiversity loss and climate change. Thus, better empirical evidence on the effectiveness of private land protection and organizational practices, such as targeting of lands for protection and choice of protection mechanism (i.e., fee simple land acquisition and conservation easements), is needed. We addressed this gap by estimating the impacts of The Nature Conservancy's (TNC) (a large nongovernmental organization with relatively decentralized management) conservation land acquisitions and easements from 1988 to 2016 in three regions of the United States (Mid-Atlantic, New England and New York, and California). We estimated impact in terms of avoided conversion by comparing natural land cover on 3179 protected parcels with matched unprotected parcels. Nineteen of 21 ecoregional plans used threats of agriculture and development to identify priorities for protection. When regions and protection mechanisms were pooled, on average there was no evidence of avoided conversion from 1988 to 2016. Accounting for mechanisms, TNC land acquisitions avoided conversion and easements did not. TNC's easements on parcels acquired by conservation partners did avoid conversion. Limitations of these results include focus on a single measure of impact, inability to capture future avoided conversion, and low land cover change accuracy in California. Our results suggest that private land protection managers who seek to avoid land conversion in the near to medium term should increase focus on areas with higher threats. Special attention should be paid to strengthening accountability and the role of partners, improving or clarifying how easements are used, and facilitating the flow of resources to work with the greatest potential impact.


Comprensión de la variación en el impacto de las áreas protegidas privadas sobre las regiones y los mecanismos de protección para guiar las prácticas organizativas Resumen La protección de terreno privado es una herramienta importante, aunque su naturaleza voluntaria puede sesgar la protección hacia parcelas menos amenazadas­lo que resulta en que la conversión no se evite o se evite muy poco. Además, muchos programas de protección privada tienen una supervisión limitada y pocos reportes de sus resultados. Por lo tanto, se necesitan mejores evidencias empíricas de la efectividad de la protección en suelo privado y las prácticas organizativas, como el enfoque en tierras para protección y la selección de los mecanismos de protección (adquisición de terrenos a título oneroso y servidumbres de conservación). Abordamos esta brecha con la estimación de impactos de las adquisiciones de suelo de The Nature Conservancy (TNC, una gran organización no gubernamental con un manejo relativamente descentralizado) y las servidumbres implementadas entre 1988 y 2016 en tres regiones de los Estados Unidos: Atlántico Medio, Nueva Inglaterra y Nueva York, y California. Estimamos el impacto en términos de la conversión que se evitó al comparar la cobertura de suelo en 3,179 parcelas protegidas con parcelas desprotegidas equivalentes. Diecinueve de los 21 planes eco­regionales usaron las amenazas a la agricultura y al desarrollo para identificar las prioridades de protección. Cuando agrupamos las regiones y los mecanismos de protección, en promedio no hubo impacto alguno. Si se consideran los mecanismos, las adquisiciones de suelo de la TNC tuvieron un impacto mientras que las servidumbres no. Las servidumbres de la TNC en las parcelas adquiridas por socios de conservación sí tuvieron un impacto, aunque esta manera de proteger sólo se presentó en las regiones del Atlántico Medio y de Nueva Inglaterra y Nueva York. Nuestros resultados sugieren que la protección privada, especialmente mediante servidumbres, puede estar sesgada hacia suelos no amenazados. Los gestores que buscan evitar la conversión del suelo a mediano o corto plazo deberían enfocarse más en las áreas con más amenazas. Se debería prestar especial atención al fortalecimiento del papel y las responsabilidades de los socios, a la mejora o aclaración de cómo se usan las servidumbres y la facilitación del flujo de recursos para trabajar con el mayor impacto potencial.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Estados Unidos , Biodiversidad , Agricultura , Cambio Climático
2.
Proc Natl Acad Sci U S A ; 112(19): 5979-84, 2015 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-25918372

RESUMEN

Environmental governance is more effective when the scales of ecological processes are well matched with the human institutions charged with managing human-environment interactions. The social-ecological systems (SESs) framework provides guidance on how to assess the social and ecological dimensions that contribute to sustainable resource use and management, but rarely if ever has been operationalized for multiple localities in a spatially explicit, quantitative manner. Here, we use the case of small-scale fisheries in Baja California Sur, Mexico, to identify distinct SES regions and test key aspects of coupled SESs theory. Regions that exhibit greater potential for social-ecological sustainability in one dimension do not necessarily exhibit it in others, highlighting the importance of integrative, coupled system analyses when implementing spatial planning and other ecosystem-based strategies.


Asunto(s)
Conservación de los Recursos Naturales , Animales , Países en Desarrollo , Ecología , Ecosistema , Explotaciones Pesqueras , Peces , Abastecimiento de Alimentos , Geografía , Humanos , México , Medio Social , Análisis de Sistemas
3.
Ecology ; 96(5): 1383-98, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26236851

RESUMEN

Variability in primary productivity and fishing pressure can shape the abundance, species composition, and diversity of marine life. Though parasites comprise nearly half of marine species, their responses to these important forces remain little explored. We quantified parasite assemblages at two spatial scales, across a gradient in productivity and fishing pressure that spans six coral islands of the Line Islands archipelago and within the largest Line Island, Kiritimati, which experiences a west-to-east gradient in fishing pressure and upwelling-driven productivity. In the across-islands data set, we found that increasing productivity was correlated with increased parasite abundance overall, but that the effects of productivity differed among parasite groups. Trophically transmitted parasites increased in abundance with increasing productivity, but directly transmitted parasites did not exhibit significant changes. This probably arises because productivity has stronger effects on the abundance of the planktonic crustaceans and herbivorous snails that serve as the intermediate hosts of trophically transmitted parasites than on the higher-trophic level fishes that are the sole hosts of directly transmitted parasites. We also found that specialist parasites increased in response to increasing productivity, while generalists did not, possibly because specialist parasites tend to be more strongly limited by host availability than are generalist parasites. After the effect of productivity was controlled for, fishing was correlated with decreases in the abundance of trophically transmitted parasites, while directly transmitted parasites appeared to track host density; we observed increases in the abundance of parasites using hosts that experienced fishing-driven compensatory increases in abundance. The within-island data set confirmed these patterns for the combined effects of productivity and fishing on parasite abundance, suggesting that our conclusions are robust across a span of spatial scales. Overall, these results indicate that there are strong and variable effects of anthropogenic and natural drivers on parasite abundance and taxonomic richness. These effects are likely to be mediated by parasite traits, particularly by parasite transmission strategies.


Asunto(s)
Ecosistema , Enfermedades de los Peces/parasitología , Explotaciones Pesqueras , Peces/parasitología , Helmintos/clasificación , Enfermedades Parasitarias en Animales/epidemiología , Animales , Helmintos/fisiología , Islas , Océano Pacífico
4.
Ecol Appl ; 23(4): 726-41, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23865225

RESUMEN

Market demand is often ignored or assumed to lead uniformly to the decline of resources. Yet little is known about how market demand influences natural resources in particular contexts, or the mediating effects of biological or institutional factors. Here, we investigate this problem by examining the Pacific red snapper (Lutjanus peru) fishery around La Paz, Mexico, where medium or "plate-sized" fish are sold to restaurants at a premium price. If higher demand for plate-sized fish increases the relative abundance of the smallest (recruit size class) and largest (most fecund) fish, this may be a market mechanism to increase stocks and fishermen's revenues. We tested this hypothesis by estimating the effect of prices on the distribution of catch across size classes using daily records of prices and catch. We linked predictions from this economic choice model to a staged-based model of the fishery to estimate the effects on the stock and revenues from harvest. We found that the supply of plate-sized fish increased by 6%, while the supply of large fish decreased by 4% as a result of a 13% price premium for plate-sized fish. This market-driven size selection increased revenues (14%) but decreased total fish biomass (-3%). However, when market-driven size selection was combined with limited institutional constraints, both fish biomass (28%) and fishermen's revenue (22%) increased. These results show that the direction and magnitude of the effects of market demand on biological populations and human behavior can depend on both biological attributes and institutional constraints. Fisheries management may capitalize on these conditional effects by implementing size-based regulations when economic and institutional incentives will enhance compliance, as in the case we describe here, or by creating compliance enhancing conditions for existing regulations.


Asunto(s)
Tamaño Corporal , Comercio , Monitoreo del Ambiente/métodos , Explotaciones Pesqueras , Peces/anatomía & histología , Animales , Conservación de los Recursos Naturales
5.
PLoS One ; 13(3): e0193716, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29494644

RESUMEN

The spread and uptake of new ideas (diffusion of innovations) is critical for organizations to adapt over time, but there is little evidence of how this happens within organizations and to their broader community. To address this, we analyzed how individuals accessed information about a recent science innovation at a large, international, biodiversity conservation non-profit-The Nature Conservancy-and then traced the flow of how this information was shared within the organization and externally, drawing on an exceptionally data-rich environment. We used surveys and tracking of individual internet activity to understand mechanisms for early-stage diffusion (knowledge seeking and sharing) following the integration of social science and evidence principles into the institutional planning framework: Conservation by Design (CbD 2.0). Communications sent to all employees effectively catalyzed 56.4% to exhibit knowledge seeking behavior, measured by individual downloads from and visits to a restricted-access site. Individuals who self-reported through a survey that they shared information about CbD 2.0 internally were more likely to have both received and sought out information about the framework. Such individuals tended to hold positions within a higher job grade, were more likely to train others on CbD as part of their job, and to enroll in other online professional development offerings. Communication strategies targeting external audiences did not appear to influence information seeking behavior. Staff who engaged in internal knowledge sharing and adopting "evidence" practices from CbD 2.0 were more likely to have shared the document externally. We found a negative correlation with external sharing behavior and in-person trainings. Our findings suggest repeated, direct email communications aimed at wide audiences can effectively promote diffusion of new ideas. We also found a wide range of employee characteristics and circumstances to be associated with knowledge diffusion behavior (at both an organizational and individual level).


Asunto(s)
Acceso a la Información , Internet , Comunicación , Humanos , Conocimiento , Organizaciones , Encuestas y Cuestionarios
6.
Integr Environ Assess Manag ; 12(2): 328-44, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26123999

RESUMEN

Businesses may be missing opportunities to account for ecosystem services in their decisions, because they do not have methods to quantify and value ecosystem services. We developed a method to quantify and value coastal protection and other ecosystem services in the context of a cost-benefit analysis of hurricane risk mitigation options for a business. We first analyze linked biophysical and economic models to examine the potential protection provided by marshes. We then applied this method to The Dow Chemical Company's Freeport, Texas facility to evaluate natural (marshes), built (levee), and hybrid (marshes and a levee designed for marshes) defenses against a 100-y hurricane. Model analysis shows that future sea-level rise decreases marsh area, increases flood heights, and increases the required levee height (12%) and cost (8%). In this context, marshes do not provide sufficient protection to the facility, located 12 km inland, to warrant a change in levee design for a 100-y hurricane. Marshes do provide some protection near shore and under smaller storm conditions, which may help maintain the coastline and levee performance in the face of sea-level rise. In sum, the net present value to the business of built defenses ($217 million [2010 US$]) is greater than natural defenses ($15 million [2010 US$]) and similar to the hybrid defense scenario ($229 million [2010 US$]). Examination of a sample of public benefits from the marshes shows they provide at least $117 million (2010 US$) in coastal protection, recreational value, and C sequestration to the public, while supporting 12 fisheries and more than 300 wildlife species. This study provides information on where natural defenses may be effective and a replicable approach that businesses can use to incorporate private, as well as public, ecosystem service values into hurricane risk management at other sites.


Asunto(s)
Conservación de los Recursos Naturales/economía , Tormentas Ciclónicas , Ecosistema , Análisis Costo-Beneficio , Modelos Teóricos , Riesgo , Humedales
7.
PLoS One ; 9(5): e96817, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24820734

RESUMEN

BACKGROUND: Economic development policies may have important economic and ecological consequences beyond the sector they target. Understanding these consequences is important to improving these policies and finding opportunities to align economic development with natural resource conservation. These issues are of particular interest to governments and non-governmental organizations that have new mandates to pursue multiple benefits. In this case study, we examined the direct and indirect economic and ecological effects of an increase in the government-controlled price for the primary agricultural product in the Republic of Kiribati, Central Pacific. METHODS/PRINCIPAL FINDINGS: We conducted household surveys and underwater visual surveys of the coral reef to examine how the government increase in the price of copra directly affected copra labor and indirectly affected fishing and the coral reef ecosystem. The islands of Kiribati are coral reef atolls and the majority of households participate in copra agriculture and fishing on the coral reefs. Our household survey data suggest that the 30% increase in the price of copra resulted in a 32% increase in copra labor and a 38% increase in fishing labor. Households with the largest amount of land in coconut production increased copra labor the most and households with the smallest amount of land in coconut production increased fishing the most. Our ecological data suggests that increased fishing labor may result in a 20% decrease in fish stocks and 4% decrease in coral reef-builders. CONCLUSIONS/SIGNIFICANCE: We provide empirical evidence to suggest that the government increase in the copra price in Kiribati had unexpected and indirect economic and ecological consequences. In this case, the economic development policy was not in alignment with conservation. These results emphasize the importance of accounting for differences in household capital and taking a systems approach to policy design and evaluation, as advocated by sustainable livelihood and ecosystem-based management frameworks.


Asunto(s)
Agricultura/economía , Arrecifes de Coral , Ecosistema , Animales , Comercio , Monitoreo del Ambiente , Gobierno , Micronesia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA