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Exotic and Invasive Species
Published in Yeqiao Wang, Terrestrial Ecosystems and Biodiversity, 2020
Not all introduced species are successful; only a fraction of each species reaches the next stage of invasion as they overcome barriers or filters (Figure 11.1). This is reflected in a general rule of thumb called the “Tens Rule,” which posits that approximately 10% of introduced species are able to escape from cultivation or captivity, 10% of the escapees can establish, and only 10% of these established species exert economic impact (termed “weeds” or “pests”).[4] Exotic species that rely on repeated introductions for their persistence, flourish and reproduce occasionally outside cultivation but eventually die out because they do not form self-replacing populations and are called casuals (subspontaneous, occasional escapes, ephemeral taxa). Those that overcome abiotic and biotic barriers to survival and regular reproduction are called naturalized (established). Invasive species are a subset of naturalized species that are able to spread far from their place of introduction and often become abundant in invaded communities.
Comparing paleo reconstructions of warm and cool season streamflow (1400–2018) for the North and South Saskatchewan River sub-basins, Western Canada
Published in Canadian Water Resources Journal / Revue canadienne des ressources hydriques, 2023
Samantha A. Kerr, Yuliya Andreichuk, David Sauchyn
We reconstructed warm and cool season streamflow for the NSR and SSR from tree-ring measurements using standard dendrohydrology methodology (Meko, Woodhouse, and Morino 2012). As with all hydroclimatic reconstructions, the underlying climate proxies represent a source of uncertainty. In this case, uncertainty regarding the tree-ring chronologies was minimized by carefully selecting chronology sites, using multiple samples per tree, and ensuring sufficient replication (sample depth) for each chronology. In MATLAB, user-written MLR (function: regress) using a forward stepwise procedure with a cross-validation stopping rule, was used to model and reconstruct warm and cool season streamflow for 600 years for the NSR (near Deer Creek) and SSR (at Highway 41). Multiple species proxies of RW-, EW-, and LW-width were used as predictors of naturalized streamflow.
Trophic status of a non-native crayfish in an oligotrophic lake: bottom-up view of a mixed warmwater and coldwater sport fishery food web
Published in Lake and Reservoir Management, 2019
John R. Loffredo, Barry C. Moore, Brian Lanouette, Raymond W. Lee, Stephen L. Katz, Benjamin K. Cross
The Buffalo Lake fishery consists of several introduced fish species and 1 native fish species, bridgelip sucker (Catostomus columbianus). Beginning in 1946–1949, and again in 1958, the Washington Department of Fish and Wildlife stocked kokanee, which quickly became naturalized (Arterburn 2003). In recent decades, several warmwater sport fish species, including largemouth bass, black crappie (Pomoxis nigromaculatus), and pumpkinseed sunfish (Lepomis gibbosus), were introduced by unknown means and also have become naturalized. CCT staff annually stock catchable-size triploid rainbow trout to supplement the coldwater recreational fishery. The CCT first documented northern crayfish in Buffalo Lake in 2002, at which time they were already characterized as extremely abundant (Fairbank 2003). Because of the high standing-stock biomass (2017 mean ∼14.4 g/m2), CCT fisheries managers have implemented a Buffalo Lake summer sport fishery without a daily bag limit for crayfish harvest (CCTFW 2012; Loffredo 2018).
Putting water security to work: addressing global challenges
Published in Water International, 2018
Chad Staddon, Christopher A. Scott
Here we would point to the all-too-naturalized tendency of most policy makers and scholars (ourselves included) to found their work on the assumed triple threat of climate-change-induced water scarcity, population rise and declining ecosystem services values. And governmentality does not need to be total or smooth, as a study of water politics in post-communist Bulgaria revealed: ‘The Djerman-Skakavitsa [water diversion] controversy reveals ragged, unstable, perhaps unknowable, spaces and analytics of government that hardly correspond to the well-oiled machine of simply-theorised disciplinary biopower’ (Staddon, 1998, p. 365).