Linking Conservation Actions with Population Viability Models: Reducing Uncertainty to Better Predict Management Effects on Viability

2011 ◽  
Author(s):  
J. M. Scott ◽  
Edward O. Garton ◽  
Brian Dennis ◽  
Jon S. Horne ◽  
Dale Goble ◽  
...  
Oryx ◽  
2011 ◽  
Vol 45 (4) ◽  
pp. 513-521 ◽  
Author(s):  
Michael Bode ◽  
Karl E. C. Brennan

AbstractMalleefowl Leipoa ocellata populations across Australia are declining and the range of the species is contracting. Despite a century of research much uncertainty remains about which factors are driving this decline. Consequently, it is also unclear which conservation actions will reduce the species’ extinction risk. In particular, we lack a quantitative understanding of malleefowl population dynamics. Here we use estimates derived from the literature to provide the first parametrization of a population viability analysis (PVA) for malleefowl. This model creates a quantitative framework for synthesizing existing information and comparing potential management strategies, and will help guide research activities by identifying critical aspects of the malleefowl’s life history. We model population dynamics as stochastic events that depend on individual characteristics, weather conditions and local management actions. Our PVA indicates that an isolated population of 32 adult birds would almost certainly decline to extinction over a 20-year period. Translocating and releasing captive-bred juveniles slows this rate of decline and intensively baiting for foxes can reverse it. Adult mortality rates have the greatest influence on population viability, and land managers should therefore prioritize conservation actions that target adult survivorship over actions that benefit earlier life stages. Quantitative research on the malleefowl should focus on the demographics of the adult life stage, their dispersal and the impacts of fire and grazing. Our analysis highlights the role of PVA models in assessing the cost-effectiveness of alternative management actions, and framing future research priorities for threatened species.


2020 ◽  
pp. 1-18
Author(s):  
MAURO ARESU ◽  
ANDREA ROTTA ◽  
ALBERTO FOZZI ◽  
ALFONSO CAMPUS ◽  
MARCO MUZZEDDU ◽  
...  

Summary Although the population of Griffon Vulture Gyps fulvus is significantly increasing in Europe, in Italy the species is still on the Red List as ‘Critically Endangered’, with the last natural population persisting on the island of Sardinia. Several episodes of poisoning hampered the success of conservation actions implemented in the years 1987–1995. In 2005 there were estimated to be only 31–32 territorial pairs, with the population occupying the territories of Alghero and Bosa. We used a long-term dataset of reproductive records from the Sardinian Griffon Vulture populations to run a population viability analysis (PVA) to evaluate the extinction risk using the Vortex simulation software. The model estimated the probability of extinction over the next five generations (estimated generation time: 11 years, simulation time used: 55 years) as 96.4% for the Alghero population, and near-zero for the Bosa population. We used sensitivity analyses to understand how uncertainty about parameter values affect model outcomes. Population projections were evaluated under different management scenarios tackling the main threats (poisoning and human disturbance) and implementing conservation actions (supplementary feeding and restocking). Our results showed that population size is a critical factor in affecting the projections of population dynamics of Griffon Vultures. Sensitivity analyses highlighted the importance of poisoning events to population persistence and showed that juvenile and adult mortality rates had a secondary impact on population viability. The only conservation measure effective in significantly increasing stochastic growth rates in the Alghero population, whose initial population was set at five individuals, was the complete removal of poisoning events. When targeting the Bosa population (initial population size 94 individuals), supplementary feeding, mitigation of the risk of poisoning episodes, restocking, and mitigation of human disturbance in the reproductive sites significantly increased stochastic growth rate. A cost-effectiveness analysis should be performed to prioritise interventions.


2011 ◽  
Vol 144 (9) ◽  
pp. 2354-2361 ◽  
Author(s):  
Esther Sebastián-González ◽  
José Antonio Sánchez-Zapata ◽  
Francisco Botella ◽  
Jordi Figuerola ◽  
Fernando Hiraldo ◽  
...  

2016 ◽  
Vol 554 ◽  
pp. 129-140 ◽  
Author(s):  
KL Nash ◽  
RA Abesamis ◽  
NAJ Graham ◽  
EC McClure ◽  
E Moland

Author(s):  
Leen Adeeb Fakhoury ◽  
Naif Adel Haddad

This paper attempts to present and discuss the outcome of the results of the key different studies and projects carried out at Salt and at Irbid historic cores.  It focuses on the executed urban heritage projects undertaken mainly by the Ministry of Tourism and Antiquities (MoTA) of Jordan in the last two decades. It discusses their different aspects through initial assessment of the loss and degradation of the cultural heritage assets of the two cities; the fragmentation and lack of connectivity between the modern and historic cores; issues of sustainability of architectural and urban heritage projects i.e. tourism planning and conservation; and reuse projects at the historic cores in relation to cultural, physical factors and development needs. It also addresses the behaviour and characteristics of the urban regeneration process in those two historic cities, starting from their documentation to examination of the different aspects of the currently adopted urban practices and policies, and their impact on the existing urban heritage, depending on the specific identity of the respective historic cores. Finally, it aims to define the main constraints and challenges for the reuse of the existing heritage fabric including the local community quality of life, while building on sustainable heritage activities accommodating tourism opportunities. This will give, at least, some indications from which we can identify a use or combination of uses, and practical steps needed for successful heritage conservation actions in Jordan, in order to retain the cultural significance of the place.


2019 ◽  
Vol 21 (2) ◽  
pp. 205-217
Author(s):  
Nádson Ricardo Leite de Souza ◽  
Vanessa Vasconcelos da Silva ◽  
Edson Henrique Almeida de Andrade ◽  
Valéria Raquel Porto de Lima

A Mata do Buraquinho consiste no maior remanescente de Mata Atlântica em área urbana do país, é cortada pelo Rio Jaguaribe, um dos afluentes do Rio Paraíba e maior rio urbano de João Pessoa/PB que, represado, forma o Açude do Buraquinho, de onde provém parte da água potável da capital paraibana. O local é declarado uma Área de Preservação Permanente desde 1989, devido à importância ambiental e, desde o ano de 2000, abriga o Jardim Botânico Benjamin Maranhão, que ocupa mais de 65% da área total, criado com a missão de fortalecer as ações de preservação e promover a intensificação dos estudos no representativo ambiente, todavia, a existência de trilhas em seu interior possibilita maior vulnerabilidade à degeneração ecossistêmica, somada aos efeitos de borda no contato com a densa urbanização do entorno. Com o objetivo de analisar os impactos ambientais negativos ocasionados por tais bordas, foram realizadas observações in loco, por meio de inventariações de parcelas concretizadas ao longo das trilhas mais frequentadas, onde se apurou diversos indicativos de degradação florestal. A partir disso, confirmou-se a autenticidade das teorias empregadas sobre os impactos ambientais negativos e a degeneração das espécies habituais, resultantes das ações de caráter antrópico, concluindo-se que a propagação dos efeitos de borda originada pela abertura de trilhas que favorecem o avanço da degradação e fazem-se necessárias ações de conservação mais rigorosas do que as em vigor, mesmo se tratando de uma área legalmente protegida.Palavras-chave: Efeitos de borda; Degeneração ecossistêmica; Mata do Buraquinho. ABSTRACTMata do Buraquinho is the largest remnant of Mata Atlântica in an urban area of the country. It is cut by the Jaguaribe River, - one of the tributaries of the Paraíba River and the largest urban river of João Pessoa/PB – which was dammed up forming the Açude do Buraquinho, from where comes part of the potable water of the capital of Paraíba. The place has been declared a Permanent Preservation Area since 1989. Due to its environmental importance and, since the year of 2000, it has sheltered the Benjamin Maranhão Botanical Garden, which occupies more than 65% of the total area. This garden was created with the mission of strengthening actions of preservation and to promote the intensification of studies in the representative environment. However, the existence of trails inside of it, allows greater vulnerability to the ecosystem degeneration, and combined with effects of border in the contact with the dense urbanization of the surrounding area. In order to analyze the negative environmental impacts caused by such edges, some observations were made in loco, through inventories of concretized plots along the most frequented trails, where several indications of forest degradation were obtained. From this, the authenticity of the theories used on the negative environmental impacts and the degeneration of the habitual species was confirmed. And resulting from actions of anthropic character, it was concluded that the propagation of the edge effects originated by the opening of tracks, favors the advance of the degradation and becomes necessary conservation actions more stringent than those in force, even in the case of a legally protected area. Keywords: Edge effects; Ecosystem Degeneration; Mata do Buraquinho. RESUMENLa “Mata do Buraquinho” es el testimonio más grande del bosque Atlántico en el área urbana de Brasil, es cortado por el Río Jaguaribe, uno de los tributarios del Río Paraíba, además, es el río urbano más grande de João Pessoa/PB, que forma la presa del “Buraquinho”, de donde proviene el suministro de agua potable para la capital del Estado de Paraíba. Esta zona es declarada un Área de Preservación Permanente desde 1989, debido a su importancia ambiental, y desde el año 2000, acoge el Jardín Botánico Benjamin Maranhão, que ocupa más de 65% del área total, creado con la misión de fortalecer las acciones de preservación y promover la intensificación de los estudios en el representativo de ambiente, sin embargo, la existencia de rutas en el interior aumenta la vulnerabilidad a la degeneración ecosistémica, añadidos a los efectos de borde que tienen contacto directo con la densa urbanización de los alrededores. Con el propósito de analizar los impactos ambientales negativos ocasionados por estos bordes, han sido realizadas observaciones "In loco", a través de inventariaciones de parcelas implementadas a lo largo de las rutas más frecuentadas, donde se ha detectado indicios de degradación forestal. Con eso, se ha confirmado la autenticidad de las teorías utilizadas sobre los impactos ambientales negativos y la degeneración de especies habituales, resultantes de acciones antrópicas, se concluye que la propagación de los efectos de borde originada por la apertura de rutas ha favorecido el avance de la degradación, con eso, son necesarias acciones de conservación todavía más estrictas de que las que existen, aún que ya sea un área protegida por la ley.Palabras-clave: Efectos de borde; Degeneración ecosistémica; Mata do Buraquinho.


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