Berry J. Brosi

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...

Single pollinator species losses reduce floral fidelity and plant reproductive function

Understanding the functional impacts of pollinator species losses on plant populations is critical given ongoing pollinator declines. Simulation models of pollination networks suggest that plant communities will be resilient to losing many or even most of the pollinator species in an ecosystem. These predictions, however, have not been tested empirically and implicitly assume that pollination efficacy is unaffected by interactions with interspecific competitors. By contrast, ecological theory and data from a wide range of ecosystems show that interspecific competition can drive variation in ecological specialization over short timescales via behavioral or morphological plasticity, although the potential implications of such changes in specialization for ecosystem functioning remain unexplored. We conducted manipulative field experiments in which we temporarily removed single pollinator species from study plots in subalpine meadows, to test the hypothesis that interactions between pollinator species can shape individual species’ functional roles via changes in foraging specialization. We show that loss of a single pollinator species reduces floral fidelity (short-term specialization) in the remaining pollinators, with significant implications for ecosystem functioning in terms of reduced plant reproduction, even when potentially effective pollinators remained in the system. Our results suggest that ongoing pollinator declines may have more serious negative implications for plant communities than is currently assumed. More broadly, we show that the individual functional contributions of species can be dynamic and shaped by the community of interspecific competitors, thereby documenting a distinct mechanism for how biodiversity can drive ecosystem functioning, with potential relevance to a wide range of taxa and systems.

Integrating conservation and development in the field: implementing ecosystem service projects

Ecosystem services can bridge biodiversity conservation and development needs, but there is little information available on how conservation organizations implement such projects. We documented 103 ecosystem service projects – from 37 countries – implemented by The Nature Conservancy (TNC) and the World Wildlife Fund (WWF). These projects commonly involved traditional conservation tactics, such as land purchase and restoration, but also adopted new approaches, such as targeting working landscapes, using new financial tools, and drawing new funding and partners from the corporate sector. We identified nine specific project types, characterized by consistent combinations of tools and activities. TNC and WWF used project types differently; TNC focused more on land purchase, whereas WWF concentrated more on developing markets. Both organizations showed some alignment of project type with socioeconomic conditions. For example, land purchases were used in countries with relatively secure property rights, while access to clean water or food was targeted when these human needs were unmet.

Statistical inference, Type II error, and decision making under the US Endangered Species Act

Critical conservation decisions have been made based on the spurious belief that “no statistically significant difference between two groups means the groups are the same”. We demonstrate this using the case of the Prebles meadow jumping mouse (Zapus hudsonius preblei), an endangered species in the US. Such faulty statistical logic has been recognized before, but ecologists have typically recommended assessing post hoc statistical power as a remedy. Statisticians, however, have shown that observed power will necessarily be low when no differences are found between two populations. Alternatives to assessments of statistical power include equivalence testing (a method rarely used by ecologists) and Bayesian or likelihood methods. Although scientists play a central role in ameliorating this problem, the courts could also assist by requiring litigated federal agency decisions to consider the risks of both Type I and Type II errors.

Pollen DNA barcoding : Current applications and future prospects.

Identification of the species origin of pollen has many applications, including assessment of plant-pollinator networks, reconstruction of ancient plant communities, product authentication, allergen monitoring, and forensics. Such applications, however, have previously been limited by microscopy-based identification of pollen, which is slow, has low taxonomic resolution, and has few expert practitioners. One alternative is pollen DNA barcoding, which could overcome these issues. Recent studies demonstrate that both chloroplast and nuclear barcoding markers can be amplified from pollen. These recent validations of pollen metabarcoding indicate that now is the time for researchers in various fields to consider applying these methods to their research programs. In this paper, we review the nascent field of pollen DNA barcoding and discuss potential new applications of this technology, highlighting existing limitations and future research developments that will improve its utility in a wide range of applications.

Ten policies for pollinators

What governments can do to safeguard pollination services Earlier this year, the first global thematic assessment from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) evaluated the state of knowledge about pollinators and pollination (1, 2). It confirmed evidence of large-scale wild pollinator declines in northwest Europe and North America and identified data shortfalls and an urgent need for monitoring elsewhere in the world. With high-level political commitments to support pollinators in the United States (3), the United Kingdom (4), and France (5); encouragement from the Convention on Biological Diversitys (CBDs) scientific advice body (6); and the issue on the agenda for next months Conference of the Parties to the CBD, we see a chance for global-scale policy change. We extend beyond the IPBES report, which we helped to write, and suggest 10 policies that governments should seriously consider to protect pollinators and secure pollination services. Our suggestions are not the only available responses but are those we consider most likely to succeed, because of synergy with international policy objectives and strategies or formulation of international policy creating opportunities for change. We make these suggestions as independent scientists and not on behalf of IPBES.

Conservation genetics of neotropical pollinators revisited: microsatellite analysis suggests that diploid males are rare in orchid bees.

Allozyme analyses have suggested that Neotropical orchid bee (Euglossini) pollinators are vulnerable because of putative high frequencies of diploid males, a result of loss of sex allele diversity in small hymenopteran populations with single locus complementary sex determination. Our analysis of 1010 males from 27 species of euglossine bees sampled across the Neotropics at 2–11 polymorphic microsatellite loci revealed only five diploid males at an overall frequency of 0.005 (95% CIs 0.002–0.010); errors through genetic nondetection of diploid males were likely small. In contrast to allozyme‐based studies, we detected very weak or insignificant population genetic structure, even for a pair of populations >500 km apart, possibly accounting for low diploid male frequencies. Technical flaws in previous allozyme‐based analyses have probably led to considerable overestimation of diploid male production in orchid bees. Other factors may have a more immediate impact on population persistence than the genetic load imposed by diploid males on these important Neotropical pollinators.

Review and future prospects for DNA barcoding methods in forensic palynology.

Pollen can be a critical forensic marker in cases where determining geographic origin is important, including investigative leads, missing persons cases, and intelligence applications. However, its use has previously been limited by the need for a high level of specialization by expert palynologists, slow speeds of identification, and relatively poor taxonomic resolution (typically to the plant family or genus level). By contrast, identification of pollen through DNA barcoding has the potential to overcome all three of these limitations, and it may seem surprising that the method has not been widely implemented. Despite what might seem a straightforward application of DNA barcoding to pollen, there are technical issues that have delayed progress. However, recent developments of standard methods for DNA barcoding of pollen, along with improvements in high-throughput sequencing technology, have overcome most of these technical issues. Based on these recent methodological developments in pollen DNA barcoding, we believe that now is the time to start applying these techniques in forensic palynology. In this article, we discuss the potential for these methods, and outline directions for future research to further improve on the technology and increase its applicability to a broader range of situations.

A digital base map for studying the Neotropical flora

Despite advances in Geographic Information Systems (GIS) and remote-sensing technology and software, to date most systematists and other botanists working on the Neotropical flora, particularly on the monographic series Flora Neotropica, have used hard-copy maps. These maps make it possible to see basic distribution patterns, but they are highly inaccurate, and the fact that the data are not compiled in digital form means that it is difficult or impossible to retrieve the metadata (i.e., the collection data and attributes of the specimen(s) associated with each point on the map), select and combine distribution datasets for various organisms, perform spatial statistics on the distributions, or overlay species distributions onto maps of soils, climate, and other environmental variables. In an effort to help modernize Neotropical plant studies and make GIS more accessible to botanists, we have developed a digital base map ofthe Americas with multiple registered map layers that can be superimposed in any combination and can be used to easily create digital distribution maps from collection lists for dissemination and analysis. This base map, freely available to botanists and systematists, was made using ArcView® GIS. Several of the layers were derived from Environmental Systems Research Institute (ESRI) datasets (ArcWorld®, ArcAtlas®, Digital Chart of the World®). For a basic version of this system we obtained additional datasets on vegetation and soils (Woods Hole Research Center), elevation (U.S. Geological Survey), and EcoRegions (World Wildlife Fund); for our own projects, we have added layers from a number of additional sources and more appropriate in scale for Amazonia and the state of Acre, Brazil. The layers are being expanded upon as new datasets become available, and we are actively seeking additional sets from other sources, including geographical institutes in individual Neotropical countries. This system makes it possible to carry out a number of rather elegant analyses and visualizations, including the following: (1) plot the distributions of species and use the overlays to easily visualize coincidence of distribution patterns with geographic and environmental features; (2) map values for morphological characters onto the distribution points in order to examine character variation over the range of the species (e.g., plotting leaf size to see latitudinal or longitudinal patterns); (3) quantitatively analyze spatial statistics (e.g., examining the relationship between fruit size and rainfall); and (4) vastly increase the agility and versatility of historical biogeography techniques. Though any botanist adept at using GIS theoretically could conduct these analyses, the Americas Base Map assembles a disparate set of high-quality, botanically relevant environmental and geographic data in one place and provides instructions that obviate the need for deep expertise in GIS. This dramatically improves access to relevant geospatial data for botanists, especially in the developing world, and should serve to expand the use of GIS in plant biogeography. We anticipate that this multifaceted approach to mapping species distributions will facilitate the work of systematists and floristicians, and that it will help Neotropical plant geography to progress from conjecture to testable hypotheses. The Americas Base Map may be utilized by any botanist affiliated with a non-profit institution and with access to Arcview®, and it is available on CD by request.

Pollinator specialization: from the individual to the community

1190 I. 1190 II. 1191 III. 1191 IV. 1193 V. 1193 1194 References 1194 SUMMARY: Most spermatophytes need conspecific pollen in order to produce seed. This need for specialization seems to conflict with the generalized nature of most plant-pollinator interactions. Specialization and generalization are dynamic - not fixed - and exist simultaneously in multiple states at different levels of biological hierarchy. Over the short term, specialization ensures conspecific pollen transfer, whereas over the long term, generalization improves system-level robustness. The balance between specialization and generalization at different scales is critical for different kinds of ecological functioning and is an important factor in plant speciation and the evolution of plant mating systems. Community context, including diversity and interaction network structure at different levels of aggregation, is a key driver of specialization dynamics.