Assessing conservation opportunity on private land: socio-economic, behavioral, and spatial dimensions

This study presents a method for assessing conservation opportunity on private land based on landholders' socio-economic, behavioral, and farm characteristics. These characteristics include age, gender, education, level of off-farm income, farm size, proportion of remnant native vegetation on-farm, and ecological value of native vegetation on-farm. A sample of landholders who own greater than 2 ha of land in the South Australian Murray-Darling Basin region were sent a mail-based survey about their values and preferences for environmental management (N = 659, 52% response). Cross-tabulations and ANOVA statistical analysis techniques were used to compare the socio-economic attributes across three landholder classes: disengaged, moderately engaged, and highly engaged in native vegetation planting. Results indicate that highly engaged landholders were more likely to be female, formally educated, hobby farmers who managed small parcels of land and have high off-farm incomes, whereas disengaged landholders held significantly stronger farming connections (more farming experience, family have lived on the farm for more generations). Spatial analysis revealed area-specific differences in conservation opportunity and conservation priority. In some areas, properties of high ecological value were managed by highly engaged landholders, but nearby properties of high value were managed by moderately engaged or disengaged landholders. Environmental managers therefore cannot assume areas of high conservation priority will be areas of high conservation opportunity. At the regional scale, the potential for revegetation seems most promising within the moderately engaged landholder group considering the vast amount of land managed by this group in areas of high ecological value, particularly within the less represented Mallee and Coorong and Rangelands sub-regions. We suggest that incentive schemes which purchase conservation need to be targeted at disengaged landholders; mentoring schemes led by commercial farmers highly engaged in native vegetation planting should be directed at moderately engaged landholders, and; awards programs which acknowledge conservation successes should be targeted at highly engaged landholders.     

Acid Orange 7 degradation using methane as the sole carbon source and electron donor

• AO7 degradation was coupled with anaerobic methane oxidation. • Higher concentration of AO7 inhibited the degradation. • The maximum removal rate of AO7 reached 280 mg/(L·d) in HfMBR. • ANME-2d dominated the microbial community in both batch reactor and HfMBR. • ANME-2d alone or synergistic with the partner bacteria played a significant role. Azo dyes are widely applied in the textile industry but are not entirely consumed during the dyeing process and can thus be discharged to the environment in wastewater. However, azo dyes can be degraded using various electron donors, and in this paper, Acid Orange 7 (AO7) degradation performance is investigated using methane (CH₄) as the sole electron donor. Methane has multiple sources and is readily available and inexpensive. Experiments using ¹³C-labeled isotopes showed that AO7 degradation was coupled with anaerobic oxidation of methane (AOM) and, subsequently, affected by the initial concentrations of AO7. Higher concentrations of AO7 could inhibit the activity of microorganisms, which was confirmed by the long-term performance of AO7 degradation, with maximum removal rates of 8.94 mg/(L·d) in a batch reactor and 280 mg/(L·d) in a hollow fiber membrane bioreactor (HfMBR). High-throughput sequencing using 16S rRNA genes showed that Candidatus Methanoperedens, affiliated to ANME-2d, dominated the microbial community in the batch reactor and HfMBR. Additionally, the relative abundance of Proteobacteria bacteria (Phenylobacterium, Pseudomonas, and Geothermobacter) improved after AO7 degradation. This outcome suggested that ANME-2d alone, or acting synergistically with partner bacteria, played a key role in the process of AO7 degradation coupled with AOM.     

Nutrient transfer in a marine mutualism: patterns of ammonia excretion by anemonefish and uptake by giant sea anemones

Many symbioses involve multiple partners in complex, multi-level associations, yet little is known concerning patterns of nutrient transfer in multi-level marine mutualisms. We used the anemonefish symbiosis as a model system to create a balance sheet for nitrogen production and transfer within a three-way symbiotic system. We quantified diel patterns in excretion of ammonia by anemonefish and subsequent absorption by host sea anemones and zooxanthellae under laboratory conditions. Rates of ammonia excretion by the anemonefish Amphiprion bicinctus varied from a high of 1.84 μmole g⁻¹ h⁻¹ at 2 h after feeding, to a basal rate of 0.50 μmole g⁻¹ h⁻¹ at 24–36 h since the last meal. Conversely, host sea anemones Entacmaea quadricolor absorbed ammonia at a rate of 0.10 μmole g⁻¹ h⁻¹ during the daytime in ammonia-enriched seawater, but during the night reduced their absorption rate to near zero, indicating that ammonia uptake was driven by zooxanthella photosynthesis. When incubated together, net ammonia excretion was virturally zero, indicating that host anemones absorbed most of the ammonia produced by resident fish. Adult anemonefish weighed about 11 g under laboratory conditions, but on the coral reef may reach up to 64 g, resulting in a maximal potential ammonia load of >200 μmole h⁻¹ produced by two adult fish during daylight hours. In contrast, host sea anemones weighed about 47 g in the laboratory, but under field conditions, large individuals may reach 680 g, so their maximal ammonia clearance rates may reach about 70 μmole h⁻¹ during the daytime. As such, the ammonia load produced by adult anemonefish far exceeds the clearance rate of host anemones and zooxanthellae. Ammonia transfer likely occurs mainly during the daytime, when anemonefish consume zooplankton and excrete rapidly, and in turn the zooxanthellae are photosynthetically active and drive rapid ammonia uptake. We conclude that zooplanktivorous fishes that form mutualisms with coral reef cnidarians may serve as an important link between open water and benthic ecosystems, through the transfer of large quantities of nutrients to zooxanthellate hosts, thus enhancing coral reef productivity.     

Effects of timber harvesting on pond-breeding amphibian persistence: testing the evacuation hypothesis.

Numerous studies have documented the decline of amphibians following timber harvest. However, direct evidence concerning the mechanisms of population decline is lacking and hinders attempts to develop conservation or recovery plans and solutions for forest species. We summarized the mechanisms by which abundance of amphibians may initially decline following timber harvest into three testable hypotheses: (1) mortality, (2) retreat, and (3) evacuation. Here, we tested the evacuation hypothesis within a large-scale, replicated experiment. We used drift fences with pitfall traps to capture pond-breeding amphibians moving out of experimental clearcut quadrants and into control quadrants at four replicate arrays located within the Daniel Boone Conservation Area on the upper Ozark Plateau in Warren County, Missouri, USA. During the preharvest year of 2004, only 51.6% of the 312 individuals captured were moving out of pre-clearcut quadrants, and movement did not differ from random. In contrast, during both postharvest years of 2005 and 2006, the number of captures along the quadrant edge increased, and a higher proportion of individuals (59.9% and 56.6%, respectively, by year) were moving out of clearcut quadrants than entering. Salamanders moved out of clearcuts in large percentages (Ambystoma annulatum, 78.2% in 2005, 78.2% in 2006; A. maculatum, 64.0% in 2005, 57.1% in 2006). Frogs and toads also moved out of clearcut quadrants, but in lower percentages (Bufo americanus, 59.6% in 2005, 53.3% in 2006; Rana clamitans, 52.7% in 2006). Salamanders moved out of clearcuts with low-wood treatments more than out of clearcuts with high-wood treatments. Movement of salamanders out of clearcuts was independent of sex. Estimated movement out of clearcuts represented between 8.7% and 35.0% of the total breeding adults captured for two species of salamanders. Although we recognize that some portion of the amphibian population may retreat underground for short periods and others may not survive the effects of timber harvest, these data are the first direct evidence showing that individuals are capable of leaving clearcuts and shifting habitat use.     

Hyperspectral Characteristics of Canopy Components and Structure for Phenological Assessment of an Invasive Weed

Spectral reflectance values of four canopy components (stems, buds, opening flowers, and postflowers of yellow starthistle (Centaurea solstitialis)) were measured to describe their spectral characteristics. We then physically combined these canopy components to simulate the flowering stage indicated by accumulated flower ratios (AFR) 10%, 40%, 70%, and 90%, respectively. Spectral dissimilarity and spectral angles were calculated to quantitatively identify spectral differences among canopy components and characteristic patterns of these flowering stages. This study demonstrated the ability of hyperspectral data to characterize canopy components, and identify different flowering stages. Stems had a typical spectral profile of green vegetation, which produced a spectral dissimilarity with three reproduction organs (buds, opening flowers, and postflowers). Quantitative differences between simulated flower stages depended on spectral regions and phenological stages examined. Using full-range canopy spectra, the initial flowering stage could be separated from the early peak, peak, and late flowering stages by three spectral regions, i.e. the blue absorption (around 480 nm) and red absorption (around 650 nm) regions and NIR plateau from 730 nm to 950 nm. For airborne CASI data, only the red absorption region and NIR plateau could be used to identify the flowering stages in the field. This study also revealed that the peak flowering stage was more easily recognized than any of the other three stages.     

Assessment of the uncertainty of using an inverse-dispersion technique to measure methane emissions from animals in a barn and in a small pen

Dispersion techniques are useful for assessing the effectiveness of management practices in mitigating methane (CH₄) emissions from animal operations. In this paper, the accuracy of an inverse-dispersion technique was examined for two common situations: 1) emissions from animals in a barn and 2) emissions from animals in a pen. For both situations, the accuracy of emission estimates generally increased with increasing fetch (scaled to barn height, h, or to pen width, X_s) between the source and the concentration measurement. The gas recovery ratio increased from 0.66 at 5 h to 0.93–1.03 at 10 h–25 h for the barn, and decreased from 1.59 at 0 X_s to 0.99 at 5 X_s and from 1.54 at 0 X_s to 1.09 at 5 X_s for the two small pen scenarios, due to the declining sensitivity of the dispersion model to errors in wind complexity and errors in the assumed source configuration. However, the relative uncertainty of the measured concentration increased with fetch due to the decreasing gas concentrations. Hence, improving the accuracy of emission estimates is a compromise between the source configuration sensitivity and the concentration measurement sensitivity. Fetches of about twice the size of the pen and about 10 times the height of the barn are suggested.     

Recovery of Sediment Characteristics in Moraine,Headwater Streams of Northern Minnesota After Forest Harvest1

Merten, Eric C., Nathaniel A. Hemstad, Randall K. Kolka, Raymond M. Newman, Elon S. Verry, and Bruce Vondracek, 2010. Recovery of Sediment Characteristics in Moraine, Headwater Streams of Northern Minnesota After Forest Harvest. Journal of the American Water Resources Association (JAWRA) 46(4): 733-743. DOI: 10.1111/j.1752-1688.2010.00445.x Abstract: We investigated the recovery of sediment characteristics in four moraine, headwater streams in north-central Minnesota after forest harvest. We examined changes in fine sediment levels from 1997 (preharvest) to 2007 (10 years postharvest) at study plots with upland clear felling and riparian thinning, using canopy cover, proportion of unstable banks, surficial fine substrates, residual pool depth, and streambed depth of refusal as response variables. Basin-scale year effects were significant (p < 0.001) for all responses when evaluated by repeated-measures ANOVAs. Throughout the study area, unstable banks increased for several years postharvest, coinciding with an increase in windthrow and fine sediment. Increased unstable banks may have been caused by forest harvest equipment, increased windthrow and exposure of rootwads, or increased discharge and bank scour. Fine sediment in the channels did not recover by summer 2007, even though canopy cover and unstable banks had returned to 1997 levels. After several storm events in fall 2007, 10 years after the initial sediment input, fine sediment was flushed from the channels and returned to 1997 levels. Although our study design did not discern the source of the initial sediment inputs (e.g., forest harvest, road crossings, other natural causes), we have shown that moraine, headwater streams can require an extended period (up to 10 years) and enabling event (e.g., high storm flows) to recover from large inputs of fine sediment.     

Drought frequency in the Volta Basin of West Africa

According to various reports, climate change is responsible for the change in rainfall amount and pattern accompanied by the various degrees of extreme events in Sahelian West Africa in recent years. Other reports also suggest that there has been a “recovery” of the rainy season (Nicholson 2005). In this study, temporal characteristics of meteorological droughts in the Volta basin, a semi-arid region in West Africa, are investigated in order to provide a guide for sustainable water resource management. For this purpose, drought intensity, areal extent and recurrence frequency is analysed using the standardised precipitation index (SPI) for a time series between 1961 and 2005 from 52 meteorology stations across the Volta basin. Using this analysis the severity of the historical droughts of 1961, 1970, 1983, 1992 and 2001 that occurred in the region are assessed and their intensity, areal extent and return periods are obtained. The drought intensity is lower than −2.0 over nearly 75% of the region, meaning that a major part of the region was under extreme drought conditions during this year. The drought of 1983/1984 has a probability of occurrence of up to 0.1 from records spanning 44 years. The areal extent of extreme drought conditions is about 90% during this drought period.     

Comparison of Wind at 500 Feet Over Minneapolis and Louisville With Geostrophic Wind

Measurements of wind speed at 500 ft on a television tower in the Minneapolis-St. Paul area are compared with geostrophic wind speeds and lapse rates. The roughness length for the builtr-up area surrounding the tower is estimated using geostrophic boundary-layer models. Similar data for Louisville are also considered. The results are relevant to-the application of existing boundary-layer models to the estimation of wind speed and turbulent mixing over a city.     

Carbon Monoxide and Lead-An Environmental Appraisal

Because of the common source, lead and CO values in the atmosphere tend to behave in a similar manner. Thus, diurnal variations in these two pollutants show a pattern related to motor vehicle traffic flow. Also, the exposure to both vary by orders of magnitude with the highest being on the road (in the car) thus setting up special dosage situations. Community sources seem to affect background level at least based on fall-off with distance. There may be a relatively wider exposure of the general population to lead and CO. While the lead levels may not be increasing in the downtown portion of the central city proper, typical central city levels of several years ago may be more diffuse and spread out, thus occurring over increasingly large portions of the community. Similarly, there may be a wider exposure of the population to CO as the levels become more nearly uniformly high over a larger area. In addition, there may be problems of a shorter term exposure to high levels of CO in commuter traffic. This may be of consequence to selected types of drivers or passengers. Finally, it should also be noted that during air pollution episodes, CO levels appear to rise with no data currently available on changes in concomitant ambient lead levels.