Developing Governance Principles for Public Natural Resources

Wildlife governance principles (WGPs) identify desirable governance characteristics for wildlife conservation in the United States (US). The types of institutional, ecological, and socio-cultural challenges that WGPs are designed to address also affect governance of public natural resources other than wildlife and in places other than the US. This raises the possibility that a similar set of governance principles might help natural resource professionals working in other resource contexts address the particular challenges they face. We describe the process by which we developed WGPs and offer seven practically oriented questions to help natural resource professionals ascertain whether a similar set of principles could improve governance in their context. In some contexts, minor modification of WGPs might be appropriate; in others, the process by which we developed WGPs could serve as a blueprint for formulating appropriate principles.     

Dynamic Changes of the Bush Encroachment in Low Altitude Area of Ethiopia

Bush encroachment is widely distributed in arid and semi-arid regions, and it has a serious impact on livestock production, especially in Africa where livestock is a primary source for the livelihoods of many people. In this study, methods of supervised classification and decision tree classification, and indexes of a land use change significance index (Ci) and a single land use dynamic degree, were applied to remote sensing imagery of Ethiopia for 1986-2016. The results show the dynamic characteristics of grassland bush encroachment in low altitude areas (pastures <1500 m above sea level) of Ethiopia in the 30 year period studied. The results revealed several interesting features of this phenomenon. (1) The area of bush encroachment showed an increasing trend, with a maximum of 3.74×10³ km² in 2003, which represented 68.97% of the total area, and declined slightly from 2003~2016. (2) Among classification types, the area of severe shrub grassland was the largest, accounting for 28.36-49.10% of the total area, while the area of moderate bush encroachment accounted for 9.77-16.68%, and slight bush encroachment accounted for 5.52-7.57%. (3) The expansion rate of shrubby grassland was 0.74% for the 30 year period, while the average annual expansion rate was 2.16% for the 8 years from 1995-2003. (4) Forest land and grassland were the two main land use types of shrub grassland transformation in low altitude areas and bush encroachment changed large amounts of forest land into grassland due to shrub grassland management. The results of this study provide basic data for revealing the impacts of development processes on subsequent bush encroachment and can inform better management for the sustainable development of grasslands in low altitude systems.     

Lithostratigraphy, Sedimentology, and Provenance of the Balfour Formation (Beaufort Group) in the Fort Beaufort–Alice Area, Eastern Cape Province, South Africa

Abstract: The Balfour Formation has a pronounced lithological variation that is characterized by alternating sandstone- and mudstone-dominated members. The sandstone-dominated Oudeberg and Barberskrans Members are composed of lithofacies that range from intraformational conglomerates to fine-grained sediments, whereas the mudstone-dominated members (Daggaboersnek, Elandsberg, and Palingkloof) are dominated by the facies Fm and Fl. Petrography, geochemistry, and a paleocurrent analysis indicated that the source rock of the Balfour Formation was to south east and the rocks had a transitional/dissected magmatic arc signature. The sandstones-rich members were deposited by seasonal and ephemeral high-energy, low-sinuous streams, and the fine-grained-rich members were formed by ephemeral meandering streams. The paleoclimates have been equated to present temperate climates; they were semiarid becoming arid towards the top of the Balfour Formation. This has been determined by reconstructing the paleolatitude of the Karoo Basin, geochemistry, paleontology, sedimentary structures, and other rock properties, like color.     

On the use of IPCC-class models to assess the impact of climate on Living Marine Resources

The study of climate impacts on Living Marine Resources (LMRs) has increased rapidly in recent years with the availability of climate model simulations contributed to the assessment reports of the Intergovernmental Panel on Climate Change (IPCC). Collaboration between climate and LMR scientists and shared understanding of critical challenges for such applications are essential for developing robust projections of climate impacts on LMRs. This paper assesses present approaches for generating projections of climate impacts on LMRs using IPCC-class climate models, recommends practices that should be followed for these applications, and identifies priority developments that could improve current projections. Understanding of the climate system and its representation within climate models has progressed to a point where many climate model outputs can now be used effectively to make LMR projections. However, uncertainty in climate model projections (particularly biases and inter-model spread at regional to local scales), coarse climate model resolution, and the uncertainty and potential complexity of the mechanisms underlying the response of LMRs to climate limit the robustness and precision of LMR projections. A variety of techniques including the analysis of multi-model ensembles, bias corrections, and statistical and dynamical downscaling can ameliorate some limitations, though the assumptions underlying these approaches and the sensitivity of results to their application must be assessed for each application. Developments in LMR science that could improve current projections of climate impacts on LMRs include improved understanding of the multi-scale mechanisms that link climate and LMRs and better representations of these mechanisms within more holistic LMR models. These developments require a strong baseline of field and laboratory observations including long time series and measurements over the broad range of spatial and temporal scales over which LMRs and climate interact. Priority developments for IPCC-class climate models include improved model accuracy (particularly at regional and local scales), inter-annual to decadal-scale predictions, and the continued development of earth system models capable of simulating the evolution of both the physical climate system and biosphere. Efforts to address these issues should occur in parallel and be informed by the continued application of existing climate and LMR models.     

Ecometrics and the paleoecological implications of Pleistocene faunas from the western coastal plains of the Cape Floristic Region,South Africa

The Pleistocene ungulate communities from the western coastal plains of South Africa's Cape Floristic Region (CFR) are diverse and dominated by grazers, in contrast to the region's Holocene and historical faunas, which are relatively species-poor and dominated by small-bodied browsers and mixed feeders. An expansion of grassy habitats is clearly implied by the Pleistocene faunas, but the presence of ruminant grazers that cannot survive the summer dry season typical of the region today suggests other important paleoecological changes. Here we use dental ecometrics to explore the paleoecological implications of the region's Pleistocene faunas. We show that the dental traits (hypsodonty and occlusal topography) of the ungulates that occurred historically in the CFR track annual and summer aridity, and we use these relationships to reconstruct past aridity. Our results indicate that the Pleistocene faunas signal paleoenvironments that were on average less arid than today, including during the summer, consistent with other lines of evidence that suggest a higher water table and expansion of well-watered habitats. Greater water availability can be explained by lower temperature and reduced evapotranspiration during cooler phases of the Pleistocene, probably coupled with enhanced groundwater recharge due to increased winter precipitation.     

Next-generation robotic planetary reconnaissance missions: A paradigm shift

A fundamentally new scientific mission concept for remote planetary surface and subsurface reconnaissance will soon replace the engineering and safety constrained mission designs of the past, allowing for optimal acquisition of geologic, paleohydrologic, paleoclimatic, and possible astrobiologic information of Mars and other extraterrestrial targets. Traditional missions have performed local ground-level reconnaissance through rovers and immobile landers, or global mapping performed by an orbiter. The former is safety and engineering constrained, affording limited detailed reconnaissance of a single site at the expense of a regional understanding, while the latter returns immense datasets, often overlooking detailed information of local and regional significance. A “tier-scalable” paradigm integrates multi-tier (orbitatmosphereground) and multi-agent (orbiterblimpsrovers/sensorwebs) hierarchical mission architectures, not only introducing mission redundancy and safety, but enabling and optimizing intelligent, unconstrained, and distributed science-driven exploration of prime locations on Mars and elsewhere, allowing for increased science return, and paving the way towards fully autonomous robotic missions.     

Calibration techniques and sampling resolution requirements for groundtruthing multibeam acoustic backscatter (EM3000) and QTC VIEW™ classification technology

Both acoustic and sediment surveys were carried out in the Broughton Archipelago, British Columbia, in order to map a former aquaculture site and calibrate acoustic surveys with georeferenced sediment properties. The acoustic surveys included EM3000 Multibeam (including backscatter) and QTC VIEW™ (Series IV) technologies, while the geotechnical survey entailed Van Veen grab sampling of surface sediments and associated analyses. The two acoustic technologies were consistent in their ability to identify distinct regions of seafloor characterized by rock outcrops, consolidated substrates, or gel-mud depositional fields. Both multibeam backscatter data and QTC VIEW™ number-coded classifications were extracted across a range of circular areas located at each georeferenced sampling station (radii: 2, 3, 4, 5, 8, 12, 16, 20 m). Statistical correlations were observed between backscatter and certain geotechnical properties, such as sediment porosity, sediment grain size fractions (<2 μm, silt content), and particulate sulfur concentration. The areal resolution of backscatter extraction was explored in terms of determining a sensitive calibration technique between backscatter and sediment properties. In general the highest r² values between backscatter and sediment variables were observed across extraction radii between 8 and 20 m. Such groundtruthing techniques could be used to interpolate seafloor characteristics between sampling stations and provide a steering tool for sampling designs associated with benthic monitoring programs.     

Carbon dioxide flux techniques performed during GasEx-98

A comprehensive study of air–sea interactions focused on improving the quantification of CO₂ fluxes and gas transfer velocities was performed within a large open ocean CO₂ sink region in the North Atlantic. This study, GasEx-98, included shipboard measurements of direct covariance CO₂ fluxes, atmospheric CO₂ profiles, atmospheric DMS profiles, water column mass balances of CO₂, and measurements of deliberate SF₆–³He tracers, along with air–sea momentum, heat, and water vapor fluxes. The large air–sea differences in partial pressure of CO₂ caused by a springtime algal bloom provided high signals for accurate CO₂ flux measurements. Measurements were performed over a wind speed range of 1–16 m s⁻¹ during the three-week process study. This first comparison between the novel air-side and more conventional water column measurements of air–sea gas transfer show a general agreement between independent air–sea gas flux techniques. These new advances in open ocean air–sea gas flux measurements demonstrate the progress in the ability to quantify air–sea CO₂ fluxes on short time scales. This capability will help improve the understanding of processes controlling the air–sea fluxes, which in turn will improve our ability to make regional and global CO₂ flux estimates.     

Abundance and size of larval fishes outside the entrance to Beaufort Inlet, North Carolina

Synoptic ichthyoplankton sampling was conducted on two transects, one on either side of Beaufort Inlet, North Carolina, during the winter immigration season of seven ocean-spawned, estuarine-dependent fishes;Brevoortia tyrannus (Atlantic menhaden),Leiostomus xanthurus (spot),Micropogonias undulatus (Atlantic croaker),Lagodon rhomboides (pinfish),Paralichthys albigutta (Gulf flounder),P. dentatus (summer flounder), andP. lethostigma (southern flounder). Densities and lengths of larvae were significantly different among sampling dates, with distance offshore, and between sides of the inlet. Flood-tide stage had minimal effect on larval densities and lengths except forP. albigutta andP. lethostigma. Changes in larval densities with distance offshore were not coherent among species; densities ofB. tyrammus increased offshore whereas densities of the other species decreased offshore. Average larval densities on a sampling date were coherent among species. Patterns in larval lengths were also coherent among the four non-flounder species. Larval densities outside of Beaufort Inlet were correlated with larval densities inside of Beaufort Inlet. Larval densities outside of Beaufort Inlet were also correlated with the north component of the wind, nearshore water temperature, and distance to the mid-shelf front. Differences in larval density across the inlet were significantly correlated with the east component of the wind. The patterns in larval densities outside of Beaufort Inlet were complex and apparently influenced by both the physical processes that supply larvae to the nearshore region and nearshore physical dynamics.