Ecological restoration projects have traditionally focused on vegetation as both a means (seeding, planting, and substrate amendments) and ends (success based upon primary productivity and vegetation diversity). This vegetation‐centric approach to ecological restoration stems from an historic emphasis on esthetics and cost but provides a limited measure of total ecosystem functioning and overlooks alternative ways to achieve current and future restoration targets. We advocate a shift to planning beyond the plant community and toward the physical and biological components necessary to initiate autogenic recovery, then guiding this process through the timely introduction of top predators and environmental modifications such as soil amendments and physical structures for animal nesting and refugia.
We examined the seasonal food habits of wolverine Gulo gulo in subboreal and interior wet-belt montane environments in British Columbia by analyzing scats collected during the course of two concurrent wolverine studies. Understanding foraging ecology for a wide-ranging carnivore such as the wolverine is important, particularly because reproduction has been demonstrated to be closely linked to food abundance. Wolverine diet was shown to vary regionally and seasonally. Regional variation was related to differences in prey availability between study areas. Moose Alces alces,c a r i b o uRangifer tarandus, and hoary marmots Marmota caligata were abundant and common prey items within both study areas. Mountain goats Oreamnos americanus and porcupine Erithizon dorsatum were more abundant and more frequent prey items in the Columbia Mountains, while snowshoe hare Lepus americanus and beaver Castor canadensis were more abundant and more frequent prey items in the Omineca Mountains. Within the winter season, diet choices by reproductive females were different than other sex and age classes. Caribou, hoary marmots and porcupines were found in significantly higher frequencies in the diet of reproductive females. Foraging observations concurred with the findings of scat analyses. Dependence of reproductive females on a species of current conservation concern (caribou) and one which could be affected by issues related to climate change (hoary marmot) may present conservation issues for wolverines in the future.
Restoration of degraded landscapes has become necessary to reverse the pervasive threats from human exploitation. Restoration requires first the monitoring of progress toward any chosen goals to determine their resilience and persistence, and second to conduct in a comparable adjacent area but with less human impact the restoration of trophic structures and ecosystem processes to act as reference systems (controls) with which we compare the viability of the chosen goal. We present here the rationale and a method for predicting the trajectory of restoration and assessing its progress toward a predetermined state, the endpoint, using a restoration index. This assessment of restoration requires that we know when a predetermined endpoint has been achieved and whether the envisioned community of species and their interactions can be restored. The restoration index can use species’ presence or density, and the rate of change of ecosystem processes. The index applies to trophic levels, functional groups, successional stages, alternative states, and novel ecosystems. Also, our method allows measurement of the resilience of ecosystems to disturbance, a desired property for conservation and management. We provide global examples to illustrate these points.
We investigated how pre-dispersal strategies may mitigate the effects of weevil infestation of acorns in a population of Quercus schottkyana, a dominant oak in Asian evergreen broad-leaved forests, and assess if weevil infestation contributes to low seedling recruitment. We counted the number of acorns produced, daily from the end of August to mid-late November for 9 years from 2006–2014. We also recorded the rate of acorn infestation by weevils and acorn germination rates of weekly collections. Annual acorn production was variable, but particularly low in 2011 and 2013. There was no trade-off between acorn production and acorn dry mass. However, acorns produced later in the season were significantly heavier. For most years: (i) the rate of weevil infestation was negatively density dependent (a greater proportion of acorns died with increased acorn density), (ii) the percentage germination of acorns was positively density dependent (proportionately more acorns germinated with increased density), and (iii) as the season progressed, the percentage of infested acorns declined while germination rates increased. Finally, (iv) maximum acorn production, percentage infestation and percentage germination were asynchronous. Although pre-dispersal mortality is important it is unlikely to be the primary factor leading to low recruitment of oak seedlings.
Accurate knowledge of geographic ranges and genetic relationships among populations is important when managing a species or population of conservation concern. Along the western coast of Canada, a subspecies of the northern goshawk ( Accipiter gentilis laingi ) is legally designated as Threatened. The range and distinctness of this form, in comparison with the broadly distributed North American subspecies ( Accipiter gentilis atricapillus ), is unclear. Given this morphological uncertainty, we analyzed genomic relationships in thousands of single nucleotide polymorphisms identified using genotyping‐by‐sequencing of high‐quality genetic samples. Results revealed a genetically distinct population of northern goshawks on the archipelago of Haida Gwaii and subtle structuring among other North American sampling regions. We then developed genotyping assays for ten loci that are highly differentiated between the two main genetic clusters, allowing inclusion of hundreds of low‐quality samples and confirming that the distinct genetic cluster is restricted to Haida Gwaii. As the laingi form was originally described as being based on Haida Gwaii (where the type specimen is from), further morphological analysis may result in this name being restricted to the Haida Gwaii genetic cluster. Regardless of taxonomic treatment, the distinct Haida Gwaii genetic cluster along with the small and declining population size of the Haida Gwaii population suggests a high risk of extinction of an ecologically and genetically distinct form of northern goshawk. Outside of Haida Gwaii, sampling regions along the coast of BC and southeast Alaska (often considered regions inhabited by laingi ) show some subtle differentiation from other North American regions. These results will increase the effectiveness of conservation management of northern goshawks in northwestern North America. More broadly, other conservation‐related studies of genetic variation may benefit from the two‐step approach we employed that first surveys genomic variation using high‐quality samples and then genotypes low‐quality samples at particularly informative loci.
Nonretention in gill‐net fisheries for Pacific salmon Oncorhynchus spp. can be relatively high and can cause a variety of impairments to nonretained fish, which often lead to immediate or delayed mortality. We sought to improve the understanding of the association between gill‐net escapement and injuries incurred by upriver‐migrating salmon by examining the relationship between gill‐net fishing effort in the Fraser River, British Columbia, and the frequency and severity of gill‐net injuries to migrating Sockeye Salmon Oncorhynchus nerka. Adult Sockeye Salmon were intercepted at a location approximately 335 km from the mouth of the Fraser River and assessed for gill‐net injuries. Gill‐net fisheries targeting Sockeye Salmon operated throughout the first 320 km of the Fraser River main stem starting at the mouth of the river. A generalized linear mixed model was used to identify the role of gill‐net fishing effort, fork length, and sex on the probability of an individual fish sustaining a gill‐net injury. Predicted probabilities of gill‐net injury ranged from 12% to 46% across all levels of fishing effort, suggesting that gill‐net injuries were more prevalent among individuals that encountered high levels of fishing effort. However, fishing effort did not seem to influence the severity of gill‐net injuries. Our results suggest that estimates of fishing effort may be useful in predicting the probability of gill‐net injury to migrating fish, which could help managers estimate en route mortality and more accurately predict spawner escapement.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.