Long-term hydrologic recovery after wildfire and post-fire forest management in the interior Pacific Northwest

Elevated wildfire activity in many regions in recent decades has increased concerns about the short- and long-term effects on water quantity, quality, and aquatic ecosystem health. Often, loss of canopy interception and transpiration, along with changes in soil structural properties, leads to elevated total annual water yields, peak flows, and low flows. Post-fire land management treatments are often used to promote forest regeneration and mitigate effects to terrestrial and aquatic ecosystems. However, few studies have investigated the longer-term effects of either wildfire or post-fire land management on catchment hydrology. Our objectives were to quantify and compare the short- and longer-term effects of both wildfire and post-fire forest management treatments on annual discharge, peak flows, low flows, and evapotranspiration (AET). We analyzed ten years of pre-fire data, along with post-fire data from 1 to 7 and 35 to 41 years after wildfire burned three experimental catchments in the Entiat Experimental Forest (EEF) in the Pacific Northwest, USA. After the fire, two of the catchments were salvage logged, aerially seeded, and fertilized, while the third catchment remained as a burned reference. We observed increases in annual discharge (150–202%), peak flows (234–283%), and low flows (42–81%), along with decreases in AET (34–45%), across all three study catchments in the first seven year period after the EEF wildfire. Comparatively, annual discharge, peak flows, lows flows, and AET had returned to pre-fire levels 35–41 years after the EEF fire in the two salvage logged and seeded catchments. Surprisingly, in the catchment that was burned but not actively managed, the annual discharge and runoff ratios remained elevated, while AET remained lower, during the period 35–41 years after the EEF fire. We posit that differences in long-term hydrologic recovery across catchments were driven by delayed vegetation recovery in the unmanaged catchment. Our study demonstrates that post-fire land management decisions have the potential to produce meaningful differences in the long-term recovery of catchment-scale ecohydrologic processes and streamflow.     

A new,valid measure of climate change understanding: associations with risk perception

The relationship between climate change understanding and other variables, including risk perception, beliefs, and worldviews, is an important consideration as we work to increase public attention to climate change. Despite significant effort to develop rigorous mechanisms for measuring affective variables, measurement of climate change understanding is often relegated to unvalidated questions or question sets. To remedy this situation, we constructed and analyzed a climate change concept inventory using a suite of validity and reliability steps, including Rasch analysis. The resultant 21-item test has a high degree of validity and reliability for measuring understanding about basic climate change processes. Inventory scores along with other variables were included in a model of climate change risk perception, providing both concurrent validity for the test and new insight into the importance of understanding, worldview, and values on risk perception. We find that environmental beliefs and cultural cognition worldview play a larger role in predicting an individual’s risk perception than knowledge. Implications for addressing climate change are considered.     

Spatial mining of migration patterns from web demographics

Volunteered Geographic Information, social media, and data from Information and Communication Technology are emerging sources of big data that contribute to the development and understanding of the spatiotemporal distribution of human population. However, the inherent anonymity of these crowd-sourced or crowd-harvested data sources lack the socioeconomic and demographic attributes to examine and explain human mobility and spatiotemporal patterns. In this paper, we investigate an Internet-based demographic data source, personal microdata databases publicly accessible on the World Wide Web (hereafter web demographics), as potential sources of aspatial and spatiotemporal information regarding the landscape of human dynamics. The objectives of this paper are twofold: (1) to develop an analytical framework to identify mobile population from web demographics as an individual-level residential history data, and (2) to explore their geographic and demographic patterns of migration. Using web demographics of Vietnamese–Americans in Texas collected in 2010 as a case study, this paper (1) addresses entity resolution and identifies mobile population through the application of a Cost-Sensitive Alternative Decision Tree (CS-ADT) algorithm, (2) investigates migration pathways and clusters to include both short- and long-distance patterns, and (3) analyze the demographic characteristics of mobile population and the functional relationship with travel distance. By linking the physical space at the individual level, this unique methodology attempts to enhance the understanding of human movement at multiple spatial scales.     

Spring water trace element geochemistry: A tool for resource assessment and reconnaissance mineral exploration

Geochemical data from 151 spring locations within the 37,000 km² South Nahanni River Basin of the Mackenzie Mountains, Northwest Territories, were analysed as part of a reconnaissance assessment of mineral potential in this large and remote region. Statistical data analyses, graphical methods and strategic grouping of springs according to geochemistry, pH and temperature, were used to identify regions with higher mineralization potential quickly and efficiently. Testing of internal consistency indicates that known world class deposits within the basin are readily detected, but by different methods. As different deposit types have different geochemical signatures a new 3-component approach was developed to analyze trace element data for signatures of mineralisation. Estimation of circulation depth, and therefore maximum potential ore depth, further refines the assessment of economic potential. The depth of circulation of the spring waters ranged from 4.7 km to less than 200 m for the entire dataset. In total, 62 spring locations were identified as having anomalous trace metal content by one or more method (approximately 40% of the dataset). Specifically, 11 spring locations were classified as anomalous by all three methods, and 17 by at least two methods, and 34 by only one method.     

The portrayal of the Australian monsoon equatorial monsoon shear line by GCMs: enhanced greenhouse scenario implications

A critical test of a general circulation model is its performance on the regional scale. In this paper we examine the summer climatology of the CSIRO4 (4-layer) climate model over the Australian tropical region. The benchmark for the study is the positioning of the monsoon equatorial trough. We compare the CSIRO4 model climatology with the climatologies from the GFDL and GISS models and we report on the sensitivity of the position of the monsoon shear line and the strength of the monsoon westerly winds to the doubling of carbon dioxide in the atmosphere. The model results show that under the greenhouse scenario the monsoon is strengthened, but the average location of the monsoon shear line is not sensitive to the doubling of CO₂. Offprint requests to: BF Ryan     

High Prevalence and Potential Impacts of Caligid Ectoparasites on Larval Atlantic Croaker (<Emphasis Type="Italic">Micropogonias undulatus</Emphasis>) in the Chesapeake Bay

Larvae of Atlantic croaker Micropogonias undulatus enter Mid-Atlantic Bight estuaries annually between September and February. A high prevalence of ectoparasitic crustacean infection of ingressing larval M. undulatus was observed in Chesapeake Bay; this ectoparasite was identified as a species of Lepeophtheirus within the copepod family Caligidae from analysis of cytochrome oxidase I sequences and scanning electron microscopy. Between 2007 and 2011, seasonal differences in prevalence were observed, with higher infection rates on fall ingressing larvae (20 % mean monthly infection rate) than in larvae entering the estuary in the winter (monthly infection rate of 6 %); the head region had the highest parasite attachment rate, being observed in 78 % of the infected fish. The potential effects of this ectoparasite on larval M. undulatus could include reductions in feeding (and thus growth) and increased susceptibility to predation.     

Cape cormorants decrease,move east and adapt foraging strategies following eastward displacement of their main prey

Numbers of Cape cormorants Phalacrocorax capensis breeding in South Africa decreased by nearly 50% from approximately 107 000 pairs in 1977–1981 to 57 000 pairs in 2010–2014. Although four colonies had >10 000 pairs in 1977–1981, there was just one such colony in 2010–2014. Almost all the decrease occurred after the early 1990s off north-west South Africa, between the Orange River estuary and Dassen Island. South of this, the number breeding in the two periods was stable, with some colonies being formed or growing rapidly in the 2000s. The proportion of South Africa’s Cape cormorants that bred south of Dassen Island increased from 35% in 1977–1981 to 66% in 2010–2014, with the opposite situation observed in the north-west. This matched a shift to the south and east in the distributions of two of the Cape cormorant’s main prey species, anchovy Engraulis encrasicolus and sardine Sardinops sagax. In 2014, an apparent scarcity of prey in the north-west resulted in Cape cormorants attempting to take bait from hooks of fishing lines over an extended period, a behaviour not previously recorded. The number of Cape cormorants breeding in the south may be constrained by the absence of large islands between Dyer Island in the west and Algoa Bay in the east. If so, it may be possible to bolster the southern population through the provision of appropriate breeding habitat, such as platforms, or restricting human disturbance at suitable mainland cliff breeding sites.     

The gamma ray spectrometer for the Solar Maximum Mission

The Solar Maximum Mission Gamma Ray Experiment (SMM GRE) utilizes an actively shielded, multicrystal scintillation spectrometer to measure the flux of solar gamma rays. The instrument provides a 476-channel pulse height spectrum (with energy resolution of 7% at 662 keV) every 16.38 s over the energy range 0.3–9 MeV. Higher time resolution (2 s) is available in three windows between 3.5 and 6.5 MeV to study prompt gamma ray line emission at 4.4 and 6.1 MeV. Gamma ray spectral analysis can be extended to 15 MeV on command. Photons in the energy band from 300–350 keV are recorded with a time resolution of 64 ms. A high energy configuration also gives the spectrum of photons in the energy range from 10–100 MeV and the flux of neutrons 20 MeV. Both have a time resolution of 2 s. Auxiliary X-ray detectors will provide spectra with 1-sec time resolution over the energy range of 10–140 keV. The instrument is designed to measure the intensity, energy, and Doppler shift of narrow gamma ray lines as well as the intensity of extremely broadened lines and the photon continuum. The main objective is to use this time and spectral information from both nuclear gamma ray lines and the photon continuum in a direct study of the dynamics of the solar flare/particle acceleration phenomena.