A Spatially Explicit Decision Support Model for Restoration of Forest Bird Habitat

Abstract:  The historical area of bottomland hardwood forest in the Mississippi Alluvial Valley has been reduced by >75%. Agricultural production was the primary motivator for deforestation; hence, clearing deliberately targeted higher and drier sites. Remaining forests are highly fragmented and hydrologically altered, with larger forest fragments subject to greater inundation, which has negatively affected many forest bird populations. We developed a spatially explicit decision support model, based on a Partners in Flight plan for forest bird conservation, that prioritizes forest restoration to reduce forest fragmentation and increase the area of forest core (interior forest >1 km from "hostile" edge). Our primary objective was to increase the number of forest patches that harbor >2000 ha of forest core, but we also sought to increase the number and area of forest cores >5000 ha. Concurrently, we targeted restoration within local (320 km²) landscapes to achieve ≥60% forest cover. Finally, we emphasized restoration of higher-elevation bottomland hardwood forests in areas where restoration would not increase forest fragmentation. Reforestation of 10% of restorable land in the Mississippi Alluvial Valley (approximately 880,000 ha) targeted at priorities established by this decision support model resulted in approximately 824,000 ha of new forest core. This is more than 32 times the amount of core forest added through reforestation of randomly located fields (approximately 25,000 ha). The total area of forest core (1.6 million ha) that resulted from targeted restoration exceeded habitat objectives identified in the Partners in Flight Bird Conservation Plan and approached the area of forest core present in the 1950s.     

Spatial Components of Bird Diversity in the Andes of Colombia: Implications for Designing a Regional Reserve System

Abstract:  Beta diversity, or the turnover in species composition among sampling sites in a region, is an important criterion for obtaining adequate representation of regional biodiversity in systems of protected areas. Recently, the additive model for partitioning regional (gamma) diversity (in opposition to the multiplicative model) has been proposed because it allows a direct measure of the contribution of beta diversity to gamma diversity. We determined avian beta diversity along latitudinal (among neighboring river drainages) and elevational axes in a 1347-km² region on the western slope of the Central Cordillera of the Colombian Andes, where a regional system of protected areas is being designed. We then compared avian beta diversity between sites based on rapid versus long-term (>1 year) inventories and between fragmented sites versus continuous forest. Overall, beta diversity represented 63.1% of gamma diversity among 16 sites. Elevational differences in species composition accounted for 43.3% of regional diversity, whereas differences among drainages accounted for 19.8%. A complementary cluster analysis showed that sites grouped by elevational zones. Rapid inventories overestimated beta diversity because of sampling effects, but the effect was biologically small. Estimators of species richness derived from species accumulation curves provided a useful alternative to compensate for undersampling in short-term surveys. Forest fragmentation increased beta diversity because of differential local extinction of populations. Nevertheless, in our region, forest fragments contributed to gamma diversity because they contained complementary sets of species. More importantly, they contained populations of special-interest species. Although the region is relatively small, our analyses indicate that spatial differentiation of the biota is an important factor for deciding number and location of protected areas in the Andean region.     

Ability of Matrix Models to Explain the Past and Predict the Future of Plant Populations

Uncertainty associated with ecological forecasts has long been recognized, but forecast accuracy is rarely quantified. We evaluated how well data on 82 populations of 20 species of plants spanning 3 continents explained and predicted plant population dynamics. We parameterized stage‐based matrix models with demographic data from individually marked plants and determined how well these models forecast population sizes observed at least 5 years into the future. Simple demographic models forecasted population dynamics poorly; only 40% of observed population sizes fell within our forecasts’ 95% confidence limits. However, these models explained population dynamics during the years in which data were collected; observed changes in population size during the data‐collection period were strongly positively correlated with population growth rate. Thus, these models are at least a sound way to quantify population status. Poor forecasts were not associated with the number of individual plants or years of data. We tested whether vital rates were density dependent and found both positive and negative density dependence. However, density dependence was not associated with forecast error. Forecast error was significantly associated with environmental differences between the data collection and forecast periods. To forecast population fates, more detailed models, such as those that project how environments are likely to change and how these changes will affect population dynamics, may be needed. Such detailed models are not always feasible. Thus, it may be wiser to make risk‐averse decisions than to expect precise forecasts from models. Habilidad de los Modelos Matriciales para Explicar el Pasado y Predecir el Futuro de las Poblaciones de Plantas     

Evaluating Wolf Translocation as a Nonlethal Method to Reduce Livestock Conflicts in the Northwestern United States

Abstract:  Successful nonlethal management of livestock predation is important for conserving rare or endangered carnivores. In the northwestern United States, wolves ( Canis lupus ) have been translocated away from livestock to mitigate conflicts while promoting wolf restoration. We assessed predation on livestock, pack establishment, survival, and homing behavior of 88 translocated wolves with radiotelemetry to determine the effectiveness of translocation in our region and consider how it may be improved. More than one-quarter of translocated wolves preyed on livestock after release. Most translocated wolves (67%) never established or joined a pack, although eight new packs resulted from translocations. Translocated wolves had lower annual survival (0.60) than other radio-collared wolves (0.73), with government removal the primary source of mortality. In northwestern Montana, where most wolves have settled in human-populated areas with livestock, survival of translocated wolves was lowest (0.41) and more wolves proportionally failed to establish packs (83%) after release. Annual survival of translocated wolves was highest in central Idaho (0.71) and more wolves proportionally established packs (44%) there than in the other two recovery areas. Translocated wolves showed a strong homing tendency; most of those that failed to home still showed directional movement toward capture sites. Wolves that successfully returned to capture sites were more likely to be adults, hard (immediately) rather than soft (temporarily held in enclosure) released, and translocated shorter distances than other wolves that did not return home. Success of translocations varied and was most affected by the area in which wolves were released. We suggest managers translocating wolves or other large carnivores consider soft releasing individuals (in family groups, if social) when feasible because this may decrease homing behavior and increase release-site fidelity.     

Research in Water Resources and Environmental Systems Modeling Some Historical Perspectives, Current Issues, and Future Directions

A recent workshop at Cornell University on water resources and environmental systems analysis provided an opportunity for about 70 attendees, mostly from North America, but some also from Asia, Europe, and South America, to discuss some of the important current issues and future research needs in this field. This paper summarizes the writers' perceptions of those informal discussions, especially pertaining to that part directed toward systems modeling. After over two decades of research and application, it is evident that there have been some beneficial impacts from various modelling applications. However, additional research needs are evident. These needs are identified and discussed.     

Birds as Suppliers of Seed Dispersal in Temperate Ecosystems: Conservation Guidelines from Real‐World Landscapes

Abstract: Seed dispersal by animals is considered a pivotal ecosystem function that drives plant‐community dynamics in natural habitats and vegetation recovery in human‐altered landscapes. Nevertheless, there is a lack of suitable ecological knowledge to develop basic conservation and management guidelines for this ecosystem service. Essential questions, such as how well the abundance of frugivorous animals predicts seeding function in different ecosystems and how anthropogenic landscape heterogeneity conditions the role of dispersers, remain poorly answered. In three temperate ecosystems, we studied seed dispersal by frugivorous birds in landscape mosaics shaped by human disturbance. By applying a standardized design across systems, we related the frequency of occurrence of bird‐dispersed seeds throughout the landscape to the abundance of birds, the habitat features, and the abundance of fleshy fruits. Abundance of frugivorous birds in itself predicted the occurrence of dispersed seeds throughout the landscape in all ecosystems studied. Even those landscape patches impoverished due to anthropogenic disturbance received some dispersed seeds when visited intensively by birds. Nonetheless, human‐caused landscape degradation largely affected seed‐deposition patterns by decreasing cover of woody vegetation or availability of fruit resources that attracted birds and promoted seed dispersal. The relative role of woody cover and fruit availability in seed dispersal by birds differed among ecosystems. Our results suggest that to manage seed dispersal for temperate ecosystem preservation or restoration one should consider abundance of frugivorous birds as a surrogate of landscape‐scale seed dispersal and an indicator of patch quality for the dispersal function; woody cover and fruit resource availability as key landscape features that drive seedfall patterns; and birds as mobile links that connect landscape patches of different degrees of degradation and habitat quality via seed deposition.     

THE EVOLUTION OF INDONESIAN HARD-MINERAL AGREEMENTS, 1967–1977

This article traces the evolution of contractual terms for hard minerals agreements in Indonesia over the period 1967–1977. It shows that, with some important exceptions, the Indonesian experience has been more or less consonant with that of other developing countries that are mineral exporters. Virtually everywhere, contract terms, particularly fiscal provisions, have been considerably tightened as host countries gained experience in negotiating and implementing hard mineral agreements. As a result, recent contracts involve measurably greater benefits for host countries than was generally the case in the 1960s. For a variety of reasons discussed in the article, the evolution to tighter contracts and more favourable terms was rapid in Indonesia. The article also demonstrates the essential equivalence between the two most prevalent forms of mineral agreements: the production-sharing contract and the contract of work. In particular, and contrary to widespread belief, the article shows, using Indonesian examples, that a contract of work can be made to match production-sharing agreements in its financial results. Le présent article retrace l'évolution des clauses contractuelles des accords sur les minéraux solides en Indonésie pour la période 1967–1977. Il montre que, à quelques exceptions importantes près, l'expérience faite par I'lndonésie dans ce domaine est fort proche de celle d'autres pays en développement exportateurs de minéraux. On assiste presque partout à un resserrement considerable des clauses contractuelles et, en particulier, des dispositions fiscales au moment où les pays hôtes acquièrent de l'experience en matière de négociations et d'exécution des accords sur les minéraux solides. En conséquence, les récents contracts ont apporté des bénéfices bien plus appréciables aux pays nôtes qu'ils ne l'ont fait généralement dans les années 60. Pour de multiples raisons exposées dans cet article, l'évolution de contrats plus stricts et de clauses plus favorables s'est avérée rapide en Indonésie. Cet article démontre également l'équivalence essentielle qui existe entre les deux formes les plus courantes d'accords sur les minéraux: des contrats de partage de la production et des contrats de travail. En particulier, et contrairement à ce que l'on pense généralement, cet article, par le biais d'exemples indonésiens, prouve qu'un contrat de travail peut s'harmoniser avec des accords de partage de la production quant à ses résultats financiers. Este artículo examina la evolución de los términos contractuales de los acuerdos sobre minerales en Indonesia durante el periodo 1967–1977. Este exámen muestra que, con algunas excepciones importantes, la experiencia de Indonesia ha sido similar a la de otros países en desarrollo exportadores de minerales. Casi en todas partes los términos contractuales, especialmente las provisiones fiscales, han tendido a ser restrictivas a medida que los países exportadores han ido adquiriendo experiencia en las negociaciones y ejecución de contratos sobre minerales. En consecuencia, los contratos recientes representan mejores beneficios para el país exportador en comparación a lo que sucedía en la década del sesenta. Debido a diferentes razones que se discuten en este artículo, la evolución hacia contratos más restrictivos y términos más favorables fué muy rápida en Indonesia. Este artículo también demuestra la equivalencia esencial entre las dos formas prevalentes de contratos sobre minerales: contratos de participación en la producción y contratos de trabajo. En especial, y contrariamente a la creencia general, el artículo muestra, usando el ejemplo de Indonesia, que el contrato de trabajo puede adecuarse de modo a obtener los mismos resultados financieros obtenibles con contratos de participación en la producción.     

Economic and Ecological Outcomes of Flexible Biodiversity Offset Systems

The commonly expressed goal of biodiversity offsets is to achieve no net loss of specific biological features affected by development. However, strict equivalency requirements may complicate trading of offset credits, increase costs due to restricted offset placement options, and force offset activities to focus on features that may not represent regional conservation priorities. Using the oil sands industry of Alberta, Canada, as a case study, we evaluated the economic and ecological performance of alternative offset systems targeting either ecologically equivalent areas (vegetation types) or regional conservation priorities (caribou and the Dry Mixedwood natural subregion). Exchanging dissimilar biodiversity elements requires assessment via a generalized metric; we used an empirically derived index of biodiversity intactness to link offsets with losses incurred by development. We considered 2 offset activities: land protection, with costs estimated as the net present value of profits of petroleum and timber resources to be paid as compensation to resource tenure holders, and restoration of anthropogenic footprint, with costs estimated from existing restoration projects. We used the spatial optimization tool MARXAN to develop hypothetical offset networks that met either the equivalent‐vegetation or conservation‐priority targets. Networks that required offsetting equivalent vegetation cost 2–17 times more than priority‐focused networks. This finding calls into question the prudence of equivalency‐based systems, particularly in relatively undeveloped jurisdictions, where conservation focuses on limiting and directing future losses. Priority‐focused offsets may offer benefits to industry and environmental stakeholders by allowing for lower‐cost conservation of valued ecological features and may invite discussion on what land‐use trade‐offs are acceptable when trading biodiversity via offsets. Resultados Económicos y Ecológicos de Sistemas de Compensación de Biodiversidad Flexible Habib et al.