Scoring the Importance of Tropical Forest Landscapes with Local People: Patterns and Insights

Good natural resource management is scarce in many remote tropical regions. Improved management requires better local consultation, but accessing and understanding the preferences and concerns of stakeholders can be difficult. Scoring, where items are numerically rated in relation to each other, is simple and seems applicable even in situations where capacity and funds are limited, but managers rarely use such methods. Here we investigate scoring with seven indigenous communities threatened by forest loss in Kalimantan, Indonesia. We aimed to clarify the forest’s multifaceted importance, using replication, cross-check exercises, and interviews. Results are sometimes surprising, but generally explained by additional investigation that sometimes provides new insights. The consistency of scoring results increases in line with community literacy and wealth. Various benefits and pitfalls are identified and examined. Aside from revealing and clarifying local preferences, scoring has unexplored potential as a quantitative technique. Scoring is an underappreciated management tool with wide potential.     

Constitutive and induced defenses to herbivory in above- and belowground plant tissues

A recent surge in attention devoted to the ecology of soil biota has prompted interest in quantifying similarities and differences between interactions occurring in above- and belowground communities. Furthermore, linkages that interconnect the dynamics of these two spatially distinct ecosystems are increasingly documented. We use a similar approach in the context of understanding plant defenses to herbivory, including how they are allocated between leaves and roots (constitutive defenses), and potential cross-system linkages (induced defenses). To explore these issues we utilized three different empirical approaches. First, we manipulated foliar and root herbivory on tobacco (Nicotiana tabacum) and measured changes in the secondary chemistry of above- and belowground tissues. Second, we reviewed published studies that compared levels of secondary chemistry between leaves and roots to determine how plants distribute putative defense chemicals across the above- and belowground systems. Last, we used meta-analysis to quantify the impact of induced responses across plant tissue types. In the tobacco system, leaf-chewing insects strongly induced higher levels of secondary metabolites in leaves but had no impact on root chemistry. Nematode root herbivores, however, elicited changes in both leaves and roots. Virtually all secondary chemicals measured were elevated in nematode-induced galls, whereas the impact of root herbivory on foliar chemistry was highly variable and depended on where chemicals were produced within the plant. Importantly, nematodes interfered with aboveground metabolites that have biosynthetic sites located in roots (e.g., nicotine) but had the opposite effect (i.e., nematodes elevated foliar expression) on chemicals produced in shoots (e.g., phenolics and terpenoids). Results from our literature review suggest that, overall, constitutive defense levels are extremely similar when comparing leaves with roots, although certain chemical classes (e.g., alkaloids, glucosinolates) are differentially allocated between above- and belowground parts. Based on a meta-analysis of induced defense studies we conclude that: (1) foliar induction generates strong responses in leaves, but much weaker responses in roots, and (2) root induction elicits responses of equal magnitude in both leaves and roots. We discuss the importance of this asymmetry and the paradox of cross-system induction in relation to optimal defense theory and interactions between above- and belowground herbivory.     

A global assessment of chromium pollution using sperm whales (Physeter macrocephalus) as an indicator species

Chromium (Cr) is a well-known human carcinogen and a potential reproductive toxicant, but its contribution to ocean pollution is poorly understood. The aim of this study was to provide a global baseline for Cr as a marine pollutant using the sperm whale (Physeter macrocephalus) as an indicator species. Biopsies were collected from free-ranging whales around the globe during the voyage of the research vessel The Odyssey. Total Cr levels were measured in 361 sperm whales collected from 16 regions around the globe detectable levels ranged from 0.9 to 122.6 μg Cr g tissue⁻¹ with a global mean of 8.8 ± 0.9 μg g⁻¹. Two whales had undetectable levels. The highest levels were found in sperm whales sampled in the waters near the Islands of Kiribati in the Pacific (mean = 44.3 ± 14.4) and the Seychelles in the Indian Ocean (mean = 19.5 ± 5.4 μg g⁻¹). The lowest mean levels were found in whales near the Canary Islands (mean = 3.7 ± 0.8 μg g⁻¹) and off of the coast of Sri Lanka (mean = 3.3 ± 0.4 μg g⁻¹). The global mean Cr level in whale skin was 28-times higher than mean Cr skin levels in humans without occupational exposure. The whale levels were more similar to levels only observed previously in human lung tissue from workers who died of Cr-induced lung cancer. We conclude that Cr pollution in the marine environment is significant and that further study is urgently needed.     

Treatment Technologies For Hazardous Wastes: Part IV A Review of Alternative Treatment Processes for Metal Bearing Hazardous Waste Streams

The U.S. Congress and the U.S. Environmental Protection Agency believe that treatment and recovery techniques should be given maximum priority when considering methods for managing the nation's generated hazardous waste. A prohibition for the disposal of certain categories of hazardous wastes either directly onto or into the land without being treated to an accepted degree prior to such disposal practice has been promulgated.¹ Wastes containing toxic metals and cyanide complexes have been selected as a group to be restricted. Due to the high generation rate associated with this category, a large capacity of waste treatment processing will be required. Existing and emerging treatment alternatives which are or have the potential to be employed for waste treatment of metal bearing wastes are presented in this paper.     

Biotoxicity evaluation of zinc oxide nanoparticles on bacterial performance of activated sludge at COD,nitrogen, and phosphorus reduction

• ZnO-NP disrupted metabolic/catabolic balance of bacteria by affecting DHA activity. • ZnO-NPs toxicity was related to Zn²⁺ ion, interaction with cell and ROS generation. • Exposure to ZnO-NPs resulted in changed bacterial community structure at sludge. • The change in the EPS content was observed during exposure to ZnO-NPs. The unique properties and growing usage of zinc oxide nanoparticles increase their release in municipal wastewater treatment plants. Therefore, these nanoparticles, by interacting with microorganisms, can fail the suitable functioning of biological systems in treatment plants. For this reason, research into the toxicity of ZnO is urgent. In the present study, the toxicity mechanism of ZnO-NPs towards microbial communities central to granular activated sludge (GAS) performance was assessed over 120-day exposure. The results demonstrate that the biotoxicity of ZnO-NPs is dependent upon its dosage, exposure time, and the extent of reactive oxygen species (ROS) production. Furthermore, GAS performance and the extracellular polymeric substances (EPS) content were significantly reduced at 50 mg/L ZnO-NPs. This exposure led to decreases in the activity of ammonia monooxygenase (25.2%) and nitrate reductase (11.9%) activity. The Field emission scanning electron microscopy images confirmed that ZnO-NPs were able to disrupt the cell membrane integrity and lead to cell/bacterial death via intracellular ROS generation which was confirmed by the Confocal Laser Scanning Microscopy analysis. After exposure to the NPs, the bacterial community composition shifted to one dominated by Gram-positive bacteria. The results of this study could help to develop environmental standards and regulations for NPs applications and emissions.     

Polyacrylamide + Al2(SO4)3 and polyacrylamide + CaO remove coliform bacteria and nutrients from swine wastewater

Animal wastes are a major contributor of nutrients and enteric microorganisms to surface water and ground water. Polyacrylamide (PAM) mixtures are an effective flocculent, and we hypothesized that they would reduce transport of microorganisms in flowing water. After waste water running at 60.0 1 min(-1) flowed over PAM + Al2(SO4)3, or PAM + CaO in furrows, total coliform bacteria (TC) and fecal coliform bacteria (FC) were reduced by 30-50% at 1 and 50 m downstream of the treatments compared to the control. In a column study, PAM + Al2(SO4)3, and PAM + CaO applied to sandy, sandy loam, loam, and clay soils reduced NH4+ and ortho-P concentrations in leachate compared to the source waste water and the control. PAM + Al2(SO4)3 and PAM + CaO applied to sandy, sandy loam and loam soils reduced both total and ortho-P, concentrations in leachate compared to he source wastewater and control treatment. In a field study, PAM + Al2(SO4)3, or PAM + CaO treatments did not consistently reduce NH4+, NO3-, ortho-P, and total P concentrations in wastewater flowing over any soil compared to inflow wastewater or the control treatment. With proper application PAM + Al2(SO4)3 and PAM + CaO may be able to reduce the numbers of enteric bacteria in slowly flowing wastewater running off animal confinement areas, reducing the amount of pollutants entering surface water and groundwater.     

Soil-atmosphere trace gas exchange in semiarid and arid zones

A review is presented on trace gas exchange of CH4, CO, N2O, and NOx arising from agriculture and natural sources in the world's semiarid and arid zones due to soil processes. These gases are important contributors to the radiative forcing and the chemistry of the atmosphere. Quantitative information is summarized from the available studies. Between 5 and 40% of the global soil-atmosphere exchange for these gases (CH4, CO, N2O, and NOx) may occur in semiarid and arid zones, but for each of these gases there are fewer than a dozen studies to support the individual estimates, and these are from a limited number of locations. Significant differences in the biophysical and chemical processes controlling these trace gas exchanges are identified through the comparison of semiarid and arid zones with the moist temperate or wet/dry savanna land regions. Therefore, there is a poorly quantified understanding of the contribution of these regions to the global trace gas cycles and atmospheric chemistry. More importantly, there is a poor understanding of the feedback between these exchanges, global change, and regional land use and air pollution issues. A set of research issues is presented.     

Spatial cost–benefit analysis of blue restoration and factors driving net benefits globally

Marine coastal ecosystems, commonly referred to as blue ecosystems, provide valuable services to society but are under increasing threat worldwide due to a variety of drivers, including eutrophication, development, land-use change, land reclamation, and climate change. Ecological restoration is sometimes necessary to facilitate recovery in coastal ecosystems. Blue restoration (i.e., in marine coastal systems) is a developing field, and projects to date have been small scale and expensive, leading to the perception that restoration may not be economically viable. We conducted a global cost–benefit analysis to determine the net benefits of restoring coral reef, mangrove, saltmarsh, and seagrass ecosystems, where the benefit is defined as the monetary value of ecosystem services. We estimated costs from published restoration case studies and used an adjusted-value-transfer method to assign benefit values to these case studies. Benefit values were estimated as the monetary value provided by ecosystem services of the restored habitats. Benefits outweighed costs (i.e., there were positive net benefits) for restoration of all blue ecosystems. Mean benefit:cost ratios for ecosystem restoration were eight to 10 times higher than prior studies of coral reef and seagrass restoration, most likely due to the more recent lower cost estimates we used. Among ecosystems, saltmarsh had the greatest net benefits followed by mangrove; coral reef and seagrass ecosystems had lower net benefits. In general, restoration in nations with middle incomes had higher (eight times higher in coral reefs and 40 times higher in mangroves) net benefits than those with high incomes. Within an ecosystem type, net benefit varied with restoration technique (coral reef and saltmarsh), ecosystem service produced (mangrove and saltmarsh), and project duration (seagrass). These results challenge the perceptions of the low economic viability of blue restoration and should encourage further targeted investment in this field.