skip to main content

Search for: All records

Creators/Authors contains: "Johnson, K."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Free, publicly-accessible full text available April 1, 2023
  2. Building on the successful Argo network of seafaring temperature and salinity sensors, work is underway to deploy 1,000 floats equipped to study ocean biogeochemistry in greater detail than ever.
    Free, publicly-accessible full text available March 17, 2023
  3. Free, publicly-accessible full text available May 4, 2023
  4. The northeastern United States experienced extensive deforestation during the seventeenth through twentieth centuries primarily for European agriculture, which peaked in the mid-nineteenth century, and followed by widespread farmstead abandonment and reforestation. Analysis of airborne light detection and ranging (LiDAR) data has revealed thousands of historical land-use features with topographic signatures across the landscape under the region’s now-dense forest canopy. This study investigates two different types of features—stone walls and relict charcoal hearths—both of which are associated with widespread deforestation in the region. Our results demonstrate that LiDAR is an effective tool in reconstructing and quantifying the distribution and magnitude of historical forest cover using these relict land use features as a reliable proxy. Furthermore, these methods allow for direct quantification of cumulative land clearing over time in each town, in addition to the extent, intensity, and spatial distribution of cleared land and forest cover.
  5. Abstract The genus Anax is a group of cosmopolitan dragonflies noted for its conspicuous migratory behaviours and large size. Here we present the first dated, species-level, multigene, molecular phylogeny for the group to test generic and species-limits, as well as the evolution of migration and range size. Using five mitochondrial and nuclear gene regions (COI, COI/COII, CYTB/ND1, ITS1 and PRMT) from 20 species, we reconstructed a phylogeny of Anax using both a Bayesian and maximum likelihood approach. We found that Anax (including its hypothesized sister group Hemianax) forms a monophyletic group, and that 12 out of 20 species tested positive for monophyly were also monophyletic. The monophyly of several species of Anax is less clear. Migratory behaviour, which is known to occur in at least nine species, is recovered as the ancestral behaviour, which was lost and subsequently gained at least three times. Geographic range size seems to be tightly associated with migratory behaviour.
  6. Smith, W.M. ; Augustyn, L. (Ed.)
  7. Abstract

    A frequent barrier to addressing some of our world’s most pressing environmental challenges is a lack of funding. Currently, environmental project funding largely comes from philanthropic and public sources, but this does not meet current needs. Increased coordination and collaboration between multiple levels and sectors of government, in addition to private sector funding, can help address the environmental funding challenge. New financial tools and strategies can enable this transition and facilitate uptake of innovative solutions. One such mechanism, the Environmental Impact Bond (EIB), is an emerging financial tool with the potential to transform the environmental funding landscape. However, these financial instruments are not well understood or recognized beyond those actively involved in EIB projects or in the field of conservation finance. As EIBs gain momentum, there is a clear need for a common framework, including definitions and nomenclature, research needs, and outlook for the future. In this paper, we define EIB mechanics, elucidate the difference between EIBs and Green Bonds, and propose a common vocabulary for the field. Drawing on first-hand experience with the few EIBs which have been deployed, we review and assess lessons learned, trends, and paths for the future. Finally, we propose a set of futuremore »targets and discuss research goals for the field to unify around. Through this work, we identify a concrete set of research gaps and objectives, providing evidence for EIBs as one important tool in the environmental finance toolbox.

    « less