Conservation and Management for Multiple Species: Integrating Field Research and Modeling into Management Decisions

Multiple-species reserves aim at supporting viable populations of selected species. Population viability analysis (PVA) is a group of methods for predicting such measures as extinction risk based on species-specific data. These methods include models that simulate the dynamics of a population or a metapopulation. A PVA model for the California gnatcatcher in Orange County was developed with landscape (GIS) data on the habitat characteristics and requirements and demographic data on population dynamics of the species. The potential applications of this model include sensitivity analysis that provides guidance for planning fieldwork, designing reserves, evaluating management options, and assessing human impact. The method can be extended to multiple species by combining habitat suitability maps for selected species with weights based on the threat faced by each species, and the contribution of habitat patches to the persistence of each species. These applications and extensions, together with the ability of the model to combine habitat and demographic data, make PVA a powerful tool for the design, conservation, and management of multiple species reserves.     

Problems in Extinction Model Selection and Parameter Estimation

It is a vexing problem to achieve a consensus about the proper scientific way to assess population viability for habitat conservation plans. Rather than a hypothesis-testing approach, here it is proposed to select population models, estimate extinction parameters, and assess prediction uncertainty using a pragmatic, empirical Bayesian approach. The simplest usable models include the effects of population growth, r; carrying capacity, K; Allee threshold, N(A); and environmental stochasticity, v(r). Analytic predictions of expected extinction times are available for such models. Models that are more complex can be elaborated from this basis. Selection from a hierarchy of nesting population models can often be done through the evaluation of parameters. The estimation of the most important extinction parameters can be undertaken in a variety of ways. Time series can be analyzed to estimate r(d), v(r), rho, and K. Habitat models and individualistic population models may help estimate N(A) and K and demographic stochasticity. Fine-scale biogeography and climatological data may be useful in the estimation of a variety of parameters. Because it takes many years to estimate extinction parameters accurately for a given population of interest, the most efficient estimation procedures are desirable. I propose the use of prior information from an (as yet nonexistent) population biology database. The accumulation of local information through monitoring will improve our estimates allowing adaptive management. Uncertainty in the estimates will always remain, but it may be quantified by the posterior distributions. A crude example is discussed using treefrog population data. Although the motivations, beliefs, and biases of competing stakeholders will differ, a habitat conservation plan could accommodate this variation in the prior distributions. Field experience from monitoring will increasingly clear up any discrepancies between the opposing beliefs and the real ecosystem. As the world is an uncertain place and because there is no universal scientific method, there will always be controversy and surprises. The best we can do is (1) agree about our prior information, (2) agree about the strategy of model selection and parameter estimation, and (3) agree about our strategy for adaptive management. Perhaps the greatest impediment to such prior agreements for HCPs is the likely paranoia inspired by the use of unfamiliar statistical methodology. We need to train students of ecology in a more flexible and deeper understanding of statistics and philosophy of science.     

Community Perspectives and Conservation Needs for Dugongs (Dugong dugon) Along the Andaman Coast of Thailand

The dugong is classified as vulnerable to extinction by the World Conservation Union on the basis of declines in area or extent of occupancy, habitat quality, and actual or potential levels of exploitation. In Thailand, the largest groups of dugongs are found near islands off the Andaman coast. The authors conducted a 2-year project that included dugong population and habitat assessment as well as interviews with local fishers. The results indicate declining populations of dugongs. The largest threat to dugongs is incidental catch in fishing nets. The numbers of deaths reported place the dugong population along the Andaman Sea in danger of extirpation. Other threats include seagrass destruction both from fishing and coastal development and the use of dugong parts for medicinal purposes. Villagers still show strong ties with dugongs, and the majority favor establishing more large protected areas for the species. These should arise from an integrated national dugong and seagrass conservation strategy formulated by concerned stakeholders from government, nongovernmental organizations, scientists, and local communities. The strategy needs to be both top down and bottom up in its formation to balance existing and potential uses as well as conflicts between artisanal and commercial fishers. The strategy should include the development of educational materials and enforceable regulations, as well as the designation of community-protected seagrass beds and a system of dugong sanctuaries along the Andaman coast. An integrated management plan is needed urgently, with the continued input of concerned scientists, to monitor and increase knowledge of dugong behavior and distribution.     

Influence of fur trade,famine, and forest fires on moose and woodland caribou populations in northwestern Ontario from 1786 to 1911

Hudson’s Bay Company records were used to estimate the 1786–1911 annual number of moose (Alces alces andersonii) and caribou (Rangifer tarandus caribou) involved in trade by northern Ojibwa natives to the company post at Osnaburgh House (51°10′N 90°15′W) in northwest Ontario, Canada. The human population for the early 19th century, and the number and severity of human starvations from 1786 to 1911 were estimated. The extent of forest fires in the region around Osnaburgh was documented using a “fire-day” index computed from Hudson’s Bay Company journals and using qualitative archival information. It is argued that the human population was too small to have caused the observed early 19th century moose and caribou population decline solely through predation. Likewise, severe early 19th century famines were caused by climatic factors rather than by declines in moose and caribou numbers. Habitat change caused by increased forest fires correlates with the observed decline of caribou, while moose increased and subsequently collapsed as winter shelter was destroyed. A burgeoning human population, sustained during winter food shortages on potatoes donated by the Hudson’s Bay Company, then kept ungulate populations to low levels until the late 19th century. Only then did maturing forests and a new outbreak of fires provide renewed habitat for resurgences of, respectively, caribou and moose.     

Human impact on the Falkland Islands environment

Summary A historic analysis of human-initiated influences on the Falkland Islands ecologies is presented. Ecosystems were extensively altered by the destruction of seal and penguin communities in the late eighteenth and nineteenth centuries; and by the introduction of domesticated animals and exotic plants, the proliferation of fires, and the hunting to extinction, or near extinction, of certain animals. The harsh Falklands climate has permitted only limited recovery from some of these ravages. No island ecosystems, however remote, are spared the effects of economic and political changes influencing the rest of the world.He has published a previous article on island ecologies inThe Environmentalist (1992).     

Model-Based Selection of Areas for the Restoration of Acrocephalus paludicola Habitats in NE Germany

The global Aquatic Warbler (Acrocephalus paludicola, Vieillot, 1817) population has suffered a major decline due to the large-scale destruction of its natural habitat (fen mires). The species is at risk of extinction, especially in NE Germany/NW Poland. In this study, we developed habitat suitability models based on satellite and environmental data to identify potential areas for habitat restoration on which further surveys and planning should be focused. To create a reliable model, we used all Aquatic Warbler presences in the study area since 1990 as well as additional potentially suitable habitats identified in the field. We combined the presence/absence regression tree algorithm Cubist with the presence-only algorithm Maxent since both commonly outperform other algorithms. To integrate the separate model results, we present a new way to create a metamodel using the initial model results as variables. Additionally, a histogram approach was applied to further reduce the final search area to the most promising sites. Accuracy increased when using both remote sensing and environmental data. It was highest for the integrated metamodel (Cohen’s Kappa of 0.4, P < 0.001). The final result of this study supports the selection of the most promising sites for Aquatic Warbler habitat restoration.     

An inventory of wetland impoundments in the coastal zone of Louisiana,USA: Historical trends

We inventoried wetland impoundments in the Louisiana, USA, coastal zone from the late 1900s to 1985. Historically, impoundment of wetlands for reclamation resulted in direct wetland loss after levees (dikes) failed and the impounded area was permanently flooded, reverting not to wetland, but to open-water habitat. A current management approach is to surround wetlands by levees and water control structures, a practice termed semi-impoundment marsh management. The purpose of this semi-impoundment is to retard saltwater intrusion and reduce water level fluctuations in an attempt to reduce wetland loss, which is a serious problem in coastal Louisiana. In order to quantify the total impounded area, we used historic data and high-altitude infrared photography to map coastal impoundments. Our goal was to produce a documented inventory of wetlands intentionally impounded by levees in the coastal zone of Louisiana in order to provide a benchmark for further research. We inventoried 370,658 ha within the coastal zone that had been intentionally impounded before 1985. This area is equal to about 30% of the total wetland area in the coastal zone. Of that total area, approximately 12% (43,000 ha) is no longer impounded (i.e., failed impoundments; levees no longer exist or only remnants remain). Of the 328,000 ha still impounded, about 65% (214,000 ha) is developed (agriculture, aquaculture, urban and industrial development, and contained spoil). The remaining 35% (114,000 ha) of impoundments are in an undeveloped state (wetland or openwater habitat). In December 1985, approximately 50% (78,000 ha) of the undeveloped and failed impoundments were open-water habitat. This inventory will allow researchers to monitor future change in land-water ratios that occur within impounded wetlands and thus to assess the utility of coastal wetland management using impoundments.     

Analysis of the prescribed burning practice in the pine forest of northwestern Portugal

The ignition of low-intensity fires in the dormant season in the pine stands of north-western Portugal seeks to reduce the existing fuel hazard without compromising site quality. The purpose of this study is to characterise this practice and assess its effectiveness, based on information resulting from the normal monitoring process at the management level, and using operational guidelines, fire behaviour models and a newly developed method to classify prescribed fire severity. Although the region's humid climate strongly constrains the activity of prescribed fire, 87% of the fires analysed were undertaken under acceptable meteorological and fuel moisture conditions. In fact, most operations achieved satisfactory results. On average, prescribed fire reduces by 96% the potential intensity of a wildfire occurring under extreme weather conditions, but 36% of the treated sites would still require heavy fire fighting resources to suppress such fire, and 17% would still carry it in the tree canopy. Only 10% of the prescribed burns have an excessive impact on trees or the forest floor, while 89% (normal fire weather) or 59% (extreme fire weather) comply with both ecological integrity maintenance and wildfire protection needs. Improved planning and monitoring procedures are recommended in order to overcome the current deficiencies.     

A Strategy for Prioritizing Threats and Recovery Actions for At-Risk Species

Ensuring the persistence of at-risk species depends on implementing conservation actions that ameliorate threats. We developed and implemented a method to quantify the relative importance of threats and to prioritize recovery actions based on their potential to affect risk to Mojave desert tortoises (Gopherus agassizii). We used assessments of threat importance and elasticities of demographic rates from population matrix models to estimate the relative contributions of threats to overall increase in risk to the population. We found that urbanization, human access, military operations, disease, and illegal use of off highway vehicles are the most serious threats to the desert tortoise range-wide. These results suggest that, overall, recovery actions that decrease habitat loss, predation, and crushing will be most effective for recovery; specifically, we found that habitat restoration, topic-specific environmental education, and land acquisition are most likely to result in the greatest decrease in risk to the desert tortoise across its range. In addition, we have developed an application that manages the conceptual model and all supporting information and calculates threat severity and potential effectiveness of recovery actions. Our analytical approach provides an objective process for quantifying threats, prioritizing recovery actions, and developing monitoring metrics for those actions for adaptive management of any at-risk species.     

An intelligent disaster decision support system for increasing the sustainability of transport networks

The increase in extreme weather events arising from climate change is posing serious threats to the sustainability of transport systems, creating the need for improved tools for decision support for more effectively managing natural disasters. There are numerous transport‐related decisions that are required during the response, recovery and preparedness stages of the disaster management cycle. This paper describes the development and application of the Intelligent Disaster Decision Support System (IDDSS), which provides a platform for integrating a vast range of road network, traffic, geographic, economic and meteorological data, as well as dynamic disaster and transport models. Initial applications to the response and planning for floods and fires are presented to illustrate some of its capabilities. The IDDSS can be used to improve disaster management, which in turn will increase the sustainability of transport networks.     

Risk and resilience lessons from Venice

In the history of disasters in Venice, there are implications for modern times in terms of complex systems management and emerging threats, in particular from examples of risk management and resilience achieved by the Venetian state during outbreaks of the plague. In fourteenth century Venice, risk assessment the way we practice it today would fail to provide meaningful recommendations to reduce the casualty rate of the plague epidemic because the cause and transmission of the disease was not understood. Instead, a set of systemic actions across the social, economic, and transportation networks of the city taken by officials and doctors eventually slowed and arguably stopped the spread of the disease. These latter actions are an early example of what is now considered resilience management. Resilience management improves a complex system’s ability to prepare, absorb, recover, and adapt to unexpected threats and does so by address the capabilities at a system, rather than component, level. Resilience management can be a guide to addressing current issues of population growth and rising sea level in modern day Venice and across the globe. This paper calls for integration of resilience assessment in comprehensive risk and resilience management framework.     

Modeling the Influence of Dynamic Zoning of Forest Harvesting on Ecological Succession in a Northern Hardwoods Landscape

Dynamic zoning (systematic alteration in the spatial and temporal allocation of even-aged forest management practices) has been proposed as a means to change the spatial pattern of timber harvest across a landscape to maximize forest interior habitat while holding timber harvest levels constant. Simulation studies have established that dynamic zoning strategies produce larger tracts of interior, closed canopy forest, thus increasing the value of these landscapes for interior-dependent wildlife. We used the simulation model LANDIS to examine how the implementation of a dynamic zoning strategy would change trajectories of ecological succession in the Great Divide Ranger District of the Chequamegon–Nicolet National Forest in northern Wisconsin over 500 years. The components of dynamic zoning strategies (number of zones in a scenario and the length of the hiatus between successive entries into zones) and their interaction had highly significant impacts on patterns of forest succession. Dynamic zoning scenarios with more zones and shorter hiatus lengths increased the average amount of the forest dominated by early successional aspen (Populus sp.). Dynamic zoning scenarios with two zones produced more late successional mature northern hardwoods than scenarios with four zones. Dynamic zoning scenarios with very short (30 years) or very long (120 years) hiatus lengths resulted in more late successional mature northern hardwoods than scenarios with intermediate hiatus lengths (60 and 90 years). However, none of the dynamic scenarios produced as much late successional mature northern hardwoods as the static alternative. Furthermore, the amounts of all habitat types in all dynamic zoning scenarios fluctuated greatly in time and space relative to static alternatives, which could negatively impact wildlife species that require a stable amount of habitat above some minimum critical threshold. Indeed, implementing dynamic zoning scenarios of different designs would have both positive and negative effects on wildlife species and for other objectives of forest management.     

Perspectives on Disconnects Between Scientific Information and Management Decisions on Post-fire Recovery in Western US

Environmental regulations frequently mandate the use of “best available” science, but ensuring that it is used in decisions around the use and protection of natural resources is often challenging. In the Western US, this relationship between science and management is at the forefront of post-fire land management decisions. Recent fires, post-fire threats (e.g. flooding, erosion), and the role of fire in ecosystem health combine to make post-fire management highly visible and often controversial. This paper uses post-fire management to present a framework for understanding why disconnects between science and management decisions may occur. We argue that attributes of agencies, such as their political or financial incentives, can limit how effectively science is incorporated into decision-making. At the other end of the spectrum, the lack of synthesis or limited data in science can result in disconnects between science-based analysis of post-fire effects and agency policy and decisions. Disconnects also occur because of the interaction between the attributes of agencies and the attributes of science, such as their different spatial and temporal scales of interest. After offering examples of these disconnects in post-fire treatment, the paper concludes with recommendations to reduce disconnects by improving monitoring, increasing synthesis of scientific findings, and directing social-science research toward identifying and deepening understanding of these disconnects.     

WATER LEVEL MANAGEMENT OPPORTUNITIES FOR ECOLOGICAL BENEFIT,POOL 5 MISSISSIPPI RWER1

ABSTRACT: This paper examines the potential to manage Mississippi River water levels for ecological benefits. The study focuses on the Weaver Bottoms, a 4,000 acre backwater marsh in southeastern Minnesota (Pool 5) highly valued for fish and wildlife habitat. The Weaver Bottoms has suffered increasing loss of aquatic vegetation and associated habitat degradation since the 1960s, largely due to persistent high water, sedimentation, wave re-suspension of sediments, and poor light penetration. In other reaches of the Mississippi River, water level reductions exposing backwater sediments have produced strong vegetative responses due to subaerial exposure of seeds and sediment compaction. Water level management scenarios for Pool 5 were developed using the HEC-2 water surface profile model. Results indicate that in many years it would be possible to reduce water levels sufficiently to expose much of the Weaver Bottoms, generating a substantial vegetative response. Additional benefits could be expected since both sediment compaction and increased vegetation would reduce re-suspension of sediments. Shifting management priorities to improve habitat would temporarily impact many river users, including both commercial and recreational boaters. Water level reductions must be coordinated with their needs.     

Habitat Fragmentation in Arid Zones: A Case Study of <Emphasis Type="Italic">Linaria nigricans</Emphasis> Under Land Use Changes (SE Spain)

Habitat fragmentation due to human activities is one of the most important causes of biodiversity loss. In Mediterranean areas the species have co-evolved with traditional farming, which has recently been replaced for more severe and aggressive practices. We use a methodological approach that enables the evaluation of the impact that agriculture and land use changes have for the conservation of sensitive species. As model species, we selected Linaria nigricans, a critically endangered plant from arid and semiarid ecosystems in south-eastern Spain. A chronosequence of the evolution of the suitable habitat for the species over more than 50 years has been reconstructed and several geometrical fragmentation indices have been calculated. A new index called fragmentation cadence (FC) is proposed to quantify the historical evolution of habitat fragmentation regardless of the habitat size. The application of this index has provided objective forecasting of the changes of each remnant population of L. nigricans. The results indicate that greenhouses and construction activities (mainly for tourist purposes) exert a strong impact on the populations of this endangered species. The habitat depletion showed peaks that constitute the destruction of 85% of the initial area in only 20 years for some populations of L. nigricans. According to the forecast established by the model, a rapid extinction could take place and some populations may disappear as early as the year 2030. Fragmentation-cadence analysis can help identify population units of primary concern for its conservation, by means of the adoption of improved management and regulatory measures.     

Multiscale Indicators of Land Degradation in the Patagonian Monte,Argentina

Depletion of vegetation by overgrazing in arid environments has long-lasting effects on the environmental quality over extended geographic areas. An adequate inspection of habitat changes requires scaled up procedures that would allow assessing end-points of environmental status in broad areas that would be based on processes occurring at the plant canopy level. Our purpose was to find indicators of land degradation–conservation status for use in land monitoring programs and in planning management practices that would be amenable to further up-scaling for use with remotely sensed imagery. In several sites of the Patagonian Monte differing in the impact of grazing management, we evaluated vegetation attributes at three spatial scales. At the population scale, we found that the severity of grazing impact was characterized by the reduction of the palatable grass, P. ligularis, outside and inside shrub canopies. At the vegetation patch scale, we found that land degradation by domestic herbivore impact was characterized by changes in attributes of patch shape (radius, height, internal canopy cover) and patch abundance. At the plant community scale, we found that the structure of the plant canopy as described using Fourier analysis of cover data changed after long-term grazing impact consistently with the modifications in plant population and patch structures. We present a conceptual multiscale scenario of structural changes triggered by domestic herbivore impact, and quantitative indicators of plant structure and processes useful to develop management strategies of the Patagonian-Monte that would conserve its natural habitats. The developed end-points are also amenable for use in land conservation assessment through remotely sensed imagery.     

Prioritizing Wildlife Taxa for Biological Diversity Conservation at the Local Scale

/ We identified and ranked 108 resident and migratory wildlife taxa on John F. Kennedy Space Center (KSC) that were vulnerable to local, regional, or global extinction. We ranked taxa based on their vulnerability to extinction, their potential role for maintaining faunal integrity, and the relevance of KSC for maintaining their populations in the United States and Florida. Several taxa, not listed by agencies, were vulnerable to regional or global extinction. Many taxa not vulnerable to global extinction were vulnerable to local and regional extinction. Top predators were vulnerable to extinction because of small population size, isolation from other populations, and road mortality. Many taxa were dependent on habitat conditions at different geographic locations so that conservation required greater collaboration among land owners, managers, and researchers at local, regional, and global scales.KEY WORDS: Biological diversity; Endangered species; Conservation     

Assessing the Impacts of Future Climate Change on Protected Area Networks: A Method to Simulate Individual Species' Responses

Global climate change, along with continued habitat loss and fragmentation, is now recognized as being a major threat to future biodiversity. There is a very real threat to species, arising from the need to shift their ranges in the future to track regions of suitable climate. The Important Bird Area (IBA) network is a series of sites designed to conserve avian diversity in the face of current threats from factors such as habitat loss and fragmentation. However, in common with other networks, the IBA network is based on the assumption that the climate will remain unchanged in the future. In this article, we provide a method to simulate the occurrence of species of conservation concern in protected areas, which could be used as a first-step approach to assess the potential impacts of climate change upon such species in protected areas. We use species-climate response surface models to relate the occurrence of 12 biome-restricted African species to climate data at a coarse (quarter degree-degree latitude-longitude) resolution and then intersect the grid model output with IBA outlines to simulate the occurrence of the species in South African IBAs. Our results demonstrate that this relatively simple technique provides good simulations of current species' occurrence in protected areas. We then use basic habitat data for IBAs along with habitat preference data for the species to reduce over-prediction and further improve predictive ability. This approach can be used with future climate change scenarios to highlight vulnerable species in IBAs in the future and allow practical recommendations to be made to enhance the IBA network and minimize the predicted impacts of climate change.     

The Value of Validated Vulnerability Data for Conservation Planning in Rapidly Changing Landscapes

Data needed for informed conservation prioritization are generally greater than the data available, and surrogates are often used. Although the need to anticipate threats is recognized, the effectiveness of surrogates for predicting habitat loss (or vulnerability) to land-use change is seldom tested. Here, we compared properties of two different vulnerability surrogates to validated vulnerability—validated prediction of habitat conversion based on a recent assessment of land-use change. We found that neither surrogate was a particularly effective predictor of vulnerability. Importantly, both surrogates performed poorly in places most imminently threatened with habitat conversion. We also show that the majority of areas protected over the last two decades have low vulnerability to the most active threatening process in this biome (habitat conversion). The contrary patterns of vulnerability and protection suggest that use of validated vulnerability would help to clarify protection needs, which might lead to the improvement of conservation decisions. Our study suggests the integration of validated vulnerability into conservation planning tools may be an important requirement for effective conservation planning in rapidly changing landscapes. We apply our results to discuss the practical considerations and potential value of incorporating validated vulnerability into conservation planning tools both generally and in the context of New Zealand’s indigenous grasslands.