REGION,LANDSCAPE, AND SCALE EFFECTS ON LAKE SUPERIOR TRIBUTARY WATER QUALITY1

ABSTRACT: In 1998 and 1999, third‐order watersheds in high mature forest (HMF) and low mature forest (LMF) classes were selected along gradients of watershed storage within each of two hydrogeomorphic regions in the Lake Superior Basin to evaluate threshold effects of storage on hydrologic regimes and watershed exports. Differences were detected between regions (North and South Shore) for particulates, nutrients, and pH, with all but silica values higher for South Shore streams (p < 0.05). Mature forest effects were detected for turbidity, nutrients, color, and alkalinity, with higher values in the LMF watersheds, that is, watersheds with less that 50 percent mature forest cover. Dissolved N, ammonium, N:P, organic carbon, and color increased, while suspended solids, turbidity, and dissolved P decreased as a function of storage. Few two‐way interactions were detected between region and mature forest or watershed storage, thus threshold based classification schemes could be used to extrapolate effects across regions. Both regional differences in water quality and those associated with watershed attributes were more common for third‐order streams in the western Lake Superior drainage basin as compared with second‐order streams examined in an earlier study. Use of ecoregions alone as a basis for setting regional water quality criteria would have led to misinterpretation of reference condition and assessment of impacts in the Northern Lakes and Forest Ecoregion.     

Recovery of temperate-stream fish communities from disturbance: A review of case studies and synthesis of theory

To evaluate the relative effect of autecologic factors, site-specific factors, disturbance characteristics, and community structure on the recovery of temperate-stream fish communities, we reviewed case histories for 49 sites and recorded data on 411 recovery end points. Most data were derived from studies of low-gradient third- or fourth-order temperate streams located in forested or agricultural watersheds. Species composition, species richness, and total density all recovered within one year for over 70% of systems studied. Lotic fish communities were not resilient to press disturbances (e.g., mining, logging, channelization) in the absence of mitigation efforts (recovery time >5 to >52 yr) and in these cases recovery was limited by habitat quality. Following pulse disturbances, autecological factors, site-specific factors, and disturbance-specific factors all affected rates of recovery. Centrarchids and minnows were most resilient to disturbance, while salmonid populations were least resilient of all families considered. Species within rock-substrate/nest-spawning guilds required significantly longer time periods to either recolonize or reestablish predisturbance population densities than did species within other reproductive guilds. Recovery was enhanced by the presence of refugia but was delayed by barriers to migration, especially when source populations for recolonization were relatively distant. Median population recovery times for systems in which disturbances occurred during or immediately prior to spawning were significantly less than median recovery times for systems in which disturbances occurred immediately after spawning. There was little evidence for the influence of biotic interactions on recovery rates.     

Are we counting what counts? A closer look at environmental concern,pro-environmental behaviour,and carbon footprint

Three parallel lines of inquiry regarding individuals' support for the environment have developed within the environmental social sciences. These include individuals' concern for the environment, research on private sphere pro-environmental behaviour (PEB), i.e. household actions seeking to improve the environment (e.g. buying better light bulbs), and more recently, ecological and carbon footprints. Researchers have noted that the correlates of this third form of support for the environment are not necessarily the same as the predictors of the first two forms. Using Canadian survey data, this study examines the relationships among, and predictors of, all three forms. Evidence that there is not a link between private sphere PEB and household carbon footprints, and that measures of socio-economic status (education and income) have different effects on different types of support for the environment, invites a discussion of whether environmental social scientists are really counting what counts.     

Development and Demonstration of a Pilot-Scale Debris Washing System

Metallic, masonry, and other solid debris that may be contaminated with hazardous chemicals litter numerous hazardous waste sites in the United States. Polychlorinated biphenyls (PCBs), pesticides, lead or other metals are some of the contaminants of concern. In some cases, cleanup standards have been established (e.g., 10 μg PCBs/100 cm² for surfaces to which humans may be frequently exposed). Decontaminated debris could be either returned to the site as “clean” fill or, in the case of metallic debris, sold to a metal smelter.

This project involves the development and demonstration of a technology specifically for per forming on-site decontamination of debris. Both bench-scale and pilot-scale versions of a debris washing system (DWS) have been designed, constructed, and demonstrated. The DWS entails the application of an aqueous solution during a high-pressure spray cycle, followed by turbulent wash and rinse cycles. The aqueous cleaning solution is recovered and reconditioned for reuse concurrently with the debris-cleaning process, which minimizes the quantity of process water required to clean the debris.     

Public involvement processes, conflict, and challenges for rural residents near intensive hog farms

Large-scale hog operations have generated intense conflict in rural communities in North America, and more recently in Alberta, Canada. The structure and process of public involvement processes for intensive hog operations influences how well the core issues of concern are addressed by public officials and pork producer proponents. This study reports interview findings from 43 key players in intensive hog operation controversies across four cases in Alberta, and summarizes four inter-related areas of the public participation processes that affect levels of trust among stakeholders, thereby altering the perceived fairness and the balance of power: (1) the timing of the public participation process; (2) information sharing; (3) accessibility of the process; and (4) accountability of public institutions and policies. Recent changes to the regulations of intensive livestock operations will unlikely address core issues of conflict without incorporating the above elements of democratic public involvement processes.