No abstract

. 2003. Copper and health status of cattle grazing high-molybdenum forage from a reclaimed mine tailing site. Can. J. Anim. Sci. 83: 479-485. High concentrations (21-44 mg kg -1 dry matter) of Mo have been identified in forage in several reclaimed mining areas in British Columbia. Since Mo concentrations greater than 5 mg kg -1 in forage dry matter may result in molybdenosis because of a secondary Cu deficiency in ruminants, a study was undertaken to determine if cattle can safely graze the reclaimed land. For 12-wk grazing periods in 1994, 1995 and 1996, 32 cow/calf pairs grazed high-Mo forage at a reclaimed mine tailings site located at the Highland Valley Copper mine near Logan lake, BC. Half of the animals in the trial received a Cu supplement (All-Trace copper bolus) and the other half served as a control group. There were no significant differences (P < 0.05) in weight gain, liver Mo, serum Cu and Mo, and milk Cu and Mo between the two treatment groups of cows. Liver Cu was higher for the Cu bolus group at certain time periods in 1994 and 1995, indicating that the bolus was effective at supplying Cu. At all times, the liver Cu levels for the animals remained above the recommended critical level of 25 mg kg -1 dry matter. Animals appeared healthy and no signs of Cu deficiency were observed. . Une concentration de Mo supérieure à 5 mg par kg de matière sèche pouvant entraîner la molybdénose consécutive-ment à une carence secondaire en cuivre (Cu) chez les ruminants, les auteurs ont tenté d'établir si les bovins peuvent paître sans danger sur ces terres. Trente-deux couples vaches/veaux ont brouté dans des champs à forte concentration de Mo pendant 12 semaines en 1994, 1995 et 1996, sur d'anciens sites restaurés à la mine de cuivre Highland Valley, près de Logan Lake, en Colombie-Britannique. La moitié des animaux ont reçu un supplément de Cu (cuivre pour bol alimentaire All-Trace), l'autre moitié servant de témoins. Les auteurs n'ont relevé aucune variation significative (P < 0,05) entre les deux traitements pour le gain de poids et la concentration de Mo dans le foie, de Cu et de Mo dans le sang, et de Cu et de Mo dans le lait. Le groupe qui avait reçu le Cu alimentaire présentait plus de Cu dans le foie à certains moments, en 1994 et 1995, signe que cette technique donne de bons résultats pour compenser le manque de Cu. La concentration de Cu dans le foie des animaux reste toujours au-dessus du seuil critique recommandé de 25 mg par kg de matière sèche. Les animaux semblaient tous en bonne santé et aucun symptôme de carence en cuivre n'a été observé.

Mine reclamation succeeds when healthy, self‐sustaining ecosystems develop on previously mined lands. Regulations require reclamation of ecosystem services; however, there are few specified targets, and those that are presented are vague. Sequencing genomic DNA and transcribed RNA from environmental samples may provide critical supportive information for attempts to recreate ecosystem functions from the ground up on disturbed lands. In this review, we highlight the use of genomics to meet mine closure goals, to enhance ecosystem development, and to optimize ecosystem services inherent in self‐sustaining reclaimed ecosystems. We address the development of environmental genomics—sequencing and analysis of environmentally derived DNA—to characterize microbial communities on mine sites. We then provide four areas where genomics has proven instrumental for informing management and assisting in reclamation of mine sites in the form of bioreactors, passive treatment systems, novel gene discovery, and DNA barcoding. Finally, we describe how recently developed techniques have transferable value to mine reclamation and provide evidence for future applications of genomics and the necessary steps to integrate these data into comprehensive management of mined sites.

Questions Biosolids are a source of nutrient‐rich organic material that can be used to improve degraded or disturbed soils. Research on vegetation responses to the land application of biosolids has increased in the past 20 years, but there is no consensus on how plant communities respond to biosolids applications. What factors influence productivity and vegetative cover following biosolids application for grassland reclamation? How does the addition of biosolids impact plant community responses? Location Global, but predominantly North America and Europe. Methods To explore vegetative responses following biosolids application, we used a global systematic review and meta‐analysis of 59 articles. Our meta‐analysis used the log response ratio (LRR) as an effect size for productivity, total cover, species richness, diversity and exotic species abundance and explored covariates addressing various site characteristics and reclamation strategies. Results We found that across sites, the land application of biosolids significantly increased productivity and cover but had no significant overall effect on species richness, Shannon diversity or exotic species abundance on degraded lands. These increases in the LRR for productivity and vegetative cover were lower on sites that experienced a fire prior to biosolids application. Climatic variables like mean annual temperature were shown to alter the response of vegetative cover, where warmer sites tended to have more positive responses to biosolids. Seeding was found to increase plant cover but decrease species richness early in the reclamation process. Conclusions This area of research is growing; most of the publications we used come from the last 20 years and were mostly conducted in North America and Europe. While we can build on the present literature, there is clearly room for more research to ensure the process of reclaiming degraded ecosystems using biosolids results in desired plant communities, e.g. high native species diversity. Future research should consistently report biosolids chemical characteristics as well as application and processing methodologies.

An experiment was initiated to study the effects of rubber benthic barriers vs. aggressive cutting on the invasive aquatic emergent plant, yellow flag iris. Treatments were compared against a control at two locations within British Columbia, Canada (Vaseux Lake and Dutch Lake). Yellow flag iris response was significantly different between the two sites, but biologically the results were identical: the benthic barrier killed yellow flag iris rhizomes within 70 d of treatment. Over the extent of the research, at Vaseux Lake the effect of aggressive cutting was no different from the control, while aggressive cutting was statistically no different than the benthic barrier at Dutch Lake. Vegetation regrowth approximately 200 d after the benthic barriers were removed was not detected at either location. These results indicate that rubber benthic barriers may be an effective treatment for yellow flag iris and maybe suitable for other, similar species.