Liba Pejchar

Ecosystem Services in Decision Making: Time to Deliver

Over the past decade, efforts to value and protect ecosystem services have been promoted by many as the last, best hope for making conservation mainstream – attractive and commonplace worldwide. In theory, if we can help individuals and institutions to recognize the value of nature, then this should greatly increase investments in conservation, while at the same time fostering human well-being. In practice, however, we have not yet developed the scientific basis, nor the policy and finance mechanisms, for incorporating natural capital into resource- and land-use decisions on a large scale. Here, we propose a conceptual framework and sketch out a strategic plan for delivering on the promise of ecosystem services, drawing on emerging examples from Hawai‘i. We describe key advances in the science and practice of accounting for natural capital in the decisions of individuals, communities, corporations, and governments.

Invasive species, ecosystem services and human well-being

Although the effects of invasive alien species (IAS) on native species are well documented, the many ways in which such species impact ecosystem services are still emerging. Here we assess the costs and benefits of IAS for provisioning, regulating and cultural services, and illustrate the synergies and tradeoffs associated with these impacts using case studies that include South Africa, the Great Lakes and Hawaii. We identify services and interactions that are the least understood and propose a research and policy framework for filling the remaining knowledge gaps. Drawing on ecology and economics to incorporate the impacts of IAS on ecosystem services into decision making is key to restoring and sustaining those life-support services that nature provides and all organisms depend upon.

Should agricultural policies encourage land sparing or wildlife‐friendly farming?

As the demands on agricultural lands to produce food, fuel, and fiber continue to expand, effective strategies are urgently needed to balance biodiversity conservation and agricultural production. “Land sparing” and “wildlife-friendly farming” have been proposed as seemingly opposing strategies to achieve this balance. In land sparing, homogeneous areas of farmland are managed to maximize yields, while separate reserves target biodiversity conservation. Wildlife-friendly farming, in contrast, integrates conservation and production within more heterogeneous landscapes. Different scientific traditions underpin the two approaches. Land sparing is associated with an island model of modified landscapes, where islands of nature are seen as separate from human activities. This simple dichotomy makes land sparing easily compatible with optimization methods that attempt to allocate land uses in the most efficient way. In contrast, wildlife-friendly farming emphasizes heterogeneity, resilience, and ecological inter...

HAWAIIAN HONEYCREEPER HOME RANGE SIZE VARIES WITH HABITAT: IMPLICATIONS FOR NATIVE ACACIA KOA FORESTRY

Reforesting degraded landscapes with native, high-value timber trees may contribute to biodiversity protection while also increasing the economic value of the land. Ideally, reforested areas should have the habitat characteristics to support viable populations of native fauna. We investigated habitat use by Akiapolaau (Hemignathus munroi), an endangered Hawaiian honeycreeper, in three habitat types: a relatively intact old-growth forest, an old-growth forest with a long history of grazing, and a native Acacia koa plantation. We quantified habitat characteristics, calculated foraging preferences, mapped home ranges, measured territoriality, and determined reproductive success at all sites. We found that Akiapolaau were highly selective foragers, foraging primarily on A. koa despite its relative scarcity in the environment, and then secondarily on several subcanopy species. Home range size was significantly smaller at the intact old-growth site and the A. koa plantation, the two sites with the greater cover...

Comparing the Ecological Impacts of Wind and Oil & Gas Development: A Landscape Scale Assessment

Energy production in the United States is in transition as the demand for clean and domestic power increases. Wind energy offers the benefit of reduced emissions, yet, like oil and natural gas, it also contributes to energy sprawl. We used a diverse set of indicators to quantify the ecological impacts of oil, natural gas, and wind energy development in Colorado and Wyoming. Aerial imagery was supplemented with empirical data to estimate habitat loss, fragmentation, potential for wildlife mortality, susceptibility to invasion, biomass carbon lost, and water resources. To quantify these impacts we digitized the land-use footprint within 375 plots, stratified by energy type. We quantified the change in impacts per unit area and per unit energy produced, compared wind energy to oil and gas, and compared landscapes with and without energy development. We found substantial differences in impacts between energy types for most indicators, although the magnitude and direction of the differences varied. Oil and gas generally resulted in greater impacts per unit area but fewer impacts per unit energy compared with wind. Biologically important and policy-relevant outcomes of this study include: 1) regardless of energy type, underlying land-use matters and development in already disturbed areas resulted in fewer total impacts; 2) the number and source of potential mortality varied between energy types, however, the lack of robust mortality data limits our ability to use this information to estimate and mitigate impacts; and 3) per unit energy produced, oil and gas extraction was less impactful on an annual basis but is likely to have a much larger cumulative footprint than wind energy over time. This rapid evaluation of landscape-scale energy development impacts could be replicated in other regions, and our specific findings can help meet the challenge of balancing land conservation with society’s demand for energy.

SAP-FEEDING BEHAVIOR AND TREE SELECTION IN THE ENDANGERED AKIAPOLAAU (HEMIGNATHUS MUNROI) IN HAWAII

Abstract The Akiapolaau (Hemignathus munroi), an endangered Hawaiian honeycreeper, drills 3–5 mm deep holes in particular ohia trees (Metrosideros polymorpha) and drinks the sap that emerges, a remarkable example of convergent evolution in sap-feeding behavior with mainland woodpeckers and Australian sugar-gliders. There has been little research on how this species selects sap trees (“Aki trees”) and what advantages they confer. We marked the locations of and collected sap samples and microhabitat data from 101 Aki trees and 73 randomly selected control trees in Hakalau Forest National Wildlife Refuge, Hawaii. Aki trees were rare (2 ha−1), spatially clustered, and defended by Akiapolaau. Sap flow volume and speed were substantially greater in Aki trees than in controls. Aki trees also were larger, had thinner bark, and were more likely to be located on convex east-facing slopes where more light is available. Those results support the hypothesis that Aki trees are selected on the basis of high sap flow and a suite of unique microhabitat and tree characteristics. Sap may be an important energy source in times of low insect availability and a potent alternative to nectar for the Akiapolaau. Aki trees are both a fascinating example of niche specialization and a factor that should be considered when conserving or restoring habitat for this endangered species.

Consequences of residential development for biodiversity and human well‐being

Residential development is a leading driver of land-use change, with important implications for biodiversity, ecosystem processes, and human well-being. We reviewed over 500 published scientific articles on the biophysical, economic, and social effects of residential development and open space in the US. We concluded that current knowledge of the effects of this type of development on social and natural systems is inadequate for achieving key objectives of sustainability, including a viable environment, a robust economy, and an equitable society. Most biophysical studies measured species- or population-level responses to development, rather than attempting to understand the mechanisms underlying these responses or the associated ecosystem processes. Economic and social studies were biased toward assessing the values and benefits to individual people, with little attention given to community-level effects. Of the small number of interdisciplinary studies – less than 3% of the total examined – many reported...

Forest Restoration and Parasitoid Wasp Communities in Montane Hawai’i

Globally, most restoration efforts focus on re-creating the physical structure (flora or physical features) of a target ecosystem with the assumption that other ecosystem components will follow. Here we investigate that assumption by documenting biogeographical patterns in an important invertebrate taxon, the parasitoid wasp family Ichneumonidae, in a recently reforested Hawaiian landscape. Specifically, we test the influence of (1) planting configurations (corridors versus patches), (2) vegetation age, (3) distance from mature native forest, (4) surrounding tree cover, and (5) plant community composition on ichneumonid richness, abundance, and composition. We sampled over 7,000 wasps, 96.5% of which were not native to Hawai’i. We found greater relative richness and abundance of ichneumonids, and substantially different communities, in restored areas compared to mature forest and abandoned pasturelands. Non-native ichneumonids drive these differences; restored areas and native forest did not differ in native ichneumonid abundance. Among restored areas, ichneumonid communities did not differ by planting age or configuration. As tree cover increased within 120 m of a sampling point, ichneumonid community composition increasingly resembled that found in native forest. Similarly, native ichneumonid abundance increased with proximity to native forest. Our results suggest that restoration plantings, if situated near target forest ecosystems and in areas with higher local tree cover, can facilitate restoration of native fauna even in a highly invaded system.

Introduced birds incompletely replace seed dispersal by a native frugivore

In an era of widespread extinction and invasion, understanding the functional role of native and introduced birds in ecological processes is increasingly important. This study compared seed rain in the presence and absence of Hawaiis last abundant native frugivore, and found that introduced birds were an imperfect substitute. In the absence of the native bird, seed rain was less frequent, less species rich, and biased towards smaller seeded plants. To maintain diverse island plant communities, conservation strategies in Hawaii should focus on restoring functional populations of native dispersers, rather than relying on introduced species to fill this role.

Pollen Carried By Native and Nonnative Bees in the Large-scale Reforestation of Pastureland in Hawai'i: Implications for Pollination

Abstract: Due to habitat loss, disease, and introduction of nonnative species, many native species in Hawai‘i have gone extinct or are at risk of extinction. As a result of interspecific interactions such as pollination, the decline, loss, or introduction of species can have cascading effects on island ecosystems. We studied Hylaeus spp., Hawai‘is yellow-faced bees, the only native bees in Hawai‘i. This group of potentially important pollinators has been largely overlooked until recently, and its conservation status and ecological role are virtually unknown. We investigated how native (Hylaeus spp.) and nonnative (Apis mellifera) bees interact with flowering plants in a large-scale pasture-to-forest restoration system. We used pan traps and nets to collect bees in mature forest, remnant corridors, planted Acacia koa tracts, and open pastureland. We removed pollen from each specimen and identified it using pollen samples collected on-site. We found that Hylaeus spp. were more likely to carry less pollen and more likely to exhibit higher pollinator fidelity compared with A. mellifera. By contrast, A. mellifera was more likely to carry mixed pollen and forage on invasive plant species. This is the first investigation in Hawai‘i to compare patterns of pollen carriage between native and nonnative bees and the first study to document pollen carried by Hylaeus spp. in the context of forest restoration.