The Effects of Breeder Loss on Wolves

Abstract Managers of recovering wolf (Canis lupus) populations require knowledge regarding the potential impacts caused by the loss of territorial, breeding wolves when devising plans that aim to balance population goals with human concerns. Although ecologists have studied wolves extensively, we lack an understanding of this phenomenon as published records are sparse. Therefore, we pooled data (n = 134 cases) on 148 territorial breeding wolves (75 M and 73 F) from our research and published accounts to assess the impacts of breeder loss on wolf pup survival, reproduction, and territorial social groups. In 58 of 71 cases (84%), ≥1 pup survived, and the number or sex of remaining breeders (including multiple breeders) did not influence pup survival. Pups survived more frequently in groups of ≥6 wolves (90%) compared with smaller groups (68%). Auxiliary nonbreeders benefited pup survival, with pups surviving in 92% of cases where auxiliaries were present and 64% where they were absent. Logistic regression analysis indicated that the number of adult-sized wolves remaining after breeder loss, along with pup age, had the greatest influence on pup survival. Territorial wolves reproduced the following season in 47% of cases, and a greater proportion reproduced where one breeder had to be replaced (56%) versus cases where both breeders had to be replaced (9%). Group size was greater for wolves that reproduced the following season compared with those that did not reproduce. Large recolonizing (>75 wolves) and saturated wolf populations had similar times to breeder replacement and next reproduction, which was about half that for small recolonizing (≤75 wolves) populations. We found inverse relationships between recolonizing population size and time to breeder replacement (r= —0.37) and time to next reproduction (r= —0.36). Time to breeder replacement correlated strongly with time to next reproduction (r=0.97). Wolf social groups dissolved and abandoned their territories subsequent to breeder loss in 38% of cases. Where groups dissolved, wolves reestablished territories in 53% of cases, and neighboring wolves usurped territories in an additional 21% of cases. Fewer groups dissolved where breeders remained (26%) versus cases where breeders were absent (85%). Group size after breeder loss was smaller where groups dissolved versus cases where groups did not dissolve. To minimize negative impacts, we recommend that managers of recolonizing wolf populations limit lethal control to solitary individuals or territorial pairs where possible, because selective removal of pack members can be difficult. When reproductive packs are to be managed, we recommend that managers only remove wolves from reproductive packs when pups are ≥6 months old and packs contain ≥6 members (including ≥3 ad-sized wolves). Ideally, such packs should be close to neighboring packs and occur within larger (≥75 wolves) recolonizing populations.     

Effects of stream flooding on the distribution and diversity of groundwater‐dependent vegetation in riparian areas

1. Effects of the frequency and duration of flooding on the structural and functional characteristics of riparian vegetation were studied at four sites (n = 80, 50 × 50 cm, plots) along medium‐sized naturally meandering lowland streams. Special focus was on rich fens, which – due to their high species richness – are of high priority in nature conservation. 2. Reed beds, rich fens and meadows were all regularly flooded during the 20‐year study period, with a higher frequency in reed bed areas than in rich fen and meadow areas. In rich fens, species richness was higher in low frequency flooded areas (≤3 year^?1) than in areas with a high frequency of flooding (>3 year^?1) or no flooding, whereas species richness in reed beds and meadows was unaffected by flood frequency. 3. The percentage of stress‐tolerant species was higher in low intensity flooded rich fen areas than in high intensity and non‐flooded areas, indicating that the higher species richness in low frequency flooded rich fens was caused by competitive release. We found no indication that increased productivity was associated with high flooding frequencies. 4. We conclude that the restoration of morphological features in stream channels to increase the flooding regime can be beneficial for protected vegetation within riparian areas, but also that groundwater discharge thresholds and critical levels for protected vegetation should be identified and considered when introducing stream ecosystem restoration plans.     

Low night temperature and inhibition of gibberellin biosynthesis override phytochrome action and induce bud set and cold acclimation, but not dormancy in PHYA overexpressors and wild-type of hybrid aspen

Juvenile trees of temperate and boreal regions cease growth and set buds in autumn in response to short day-lengths (SD) detected by phytochrome. Growth cessation and bud set are prerequisites for the development of winter dormancy and full cold hardiness. In this study we show that the SD-requirement for bud set and cold hardening can be overcome in hybrid aspen (Populus tremula L. × tremuloides Michx.) by low night temperature and inhibition of gibberellin (GA) biosynthesis. Bud set and increased cold hardiness were observed under normally non-inductive long day-length (LD) in wild-type plants, when exposed to low night temperature and paclobutrazol. In addition, the effect of PHYA overexpression could be overcome in transgenic plants, producing bud set and cold acclimation by treatment with: SD, low night temperature and paclobutrazol. After cold acclimation, the degree of bud dormancy was lower for wild-type plants prior treated with LD and transgenic plants (overexpressing PHYA), than SD-treated, wild-type plants. Thus, low night temperature in combination with reduced GA content induced bud set and promoted cold hardiness under normally non-inductive photoperiods in hybrid aspen, but was unable to affect development of dormancy. This might suggest separate signalling pathways from phytochrome regulating the induction of cold/cold hardiness and bud dormancy in hybrid aspen or alternatively, there might be one pathway that fails to complete its action in the transgenic and paclobutrazol treated plants.     

Cross‐species amplification of 105 Lolium perenne SSR loci in 23 species within the Poaceae

Amplification of 105 Lolium perenne SSR markers was studied in 23 grass species representing seven tribes from three subfamilies of Poaceae. Twelve of the SSR markers are published for the first time. Between 2% and 96% of the SSR markers could be amplified within a given species. A subset of eight SSR markers was evaluated for polymorphism across nine of the 23 grass species. Four to seven of the markers were polymorphic within each species, with an average detection of 2.4 alleles per species.     

RAPID PURIFICATION OF SALMONELLA DNA IN MINCED MEAT AND DETECTION BY REAL-TIME PCR

Four rapid and simple DNA purification and sample treatment protocols were evaluated for detection of Salmonella enterica in spiked minced meat, using a fluorogenic 5'nuclease (TaqMan) PCR assay in an ABI-Prism 7700 Sequence Detector. The detection limit with the single separation treatment of DNeasy was found to be 6–8 CFU in just 19 end-point fluorescence (C_t) values, while this was 22 C_t for a combination of DNeasy and BactXtractor. Extraction by DNeasy resulted in C_t <22, indicating a detection limit of <10 Salmonella cells per 25g, when the samples were inoculated with Salmonella before the overnight preenrichment. The method is currently being adapted to a BioRobot 3000 platform. However, the use of paramagnetic beads (DNA Direct) resulted in poor and variable detection limit.     

Effects of light on the catabolism of [2-14C]-3-indole acetic acid in protoplasts, a chloroplast-rich fraction, and a crude cytoplasmic preparation from barley (Hordeum vulgare L)

Abstract. Combined gas chromatography-mass spectrometry has been used to identify 3-indole acetic acid in an extract from protoplasts of barley. In addition, a study has been made of the effect of light on the rate of catabolism of [2-¹⁴C]-3-indole acetic acid by protoplasts, a chloroplast-rich fraction and a crude cytoplasmic preparation from barley leaves. While light enhanced the rate of catabolism of [2-¹⁴C]-3-indok acetic acid by protoplasts and, to a lesser degree, by the chloroplast-rich fraction, it did not affect the catabolic activity of the crude, cytoplasmic fraction. These findings, when considered along with the data of Sandberg, Jensen & Crozier (1983), imply that the rate of turnover of 3-indole acetic acid, in both protoplasts and chloroplasts, is more rapid in light than it is in darkness.     

Higher plants express 3-deoxy-D-manno-octulosonate 8-phosphate synthase

Abstract. The enzymatic activity of 3-deoxy- D-manno -octulosonate 8-phosphate (KDOP) synthase was detected in eight diverse plant species, thus providing enzymological data consistent with recent reports of the presence of 3-deoxy- D-manno -octulosonate in plant cell walls. KDOP synthase from spinach was partially purified and characterized. It possessed weak activity as 3-deoxy- D-arabino -heptulosonate 7-phosphate (DAHP) synthase. In the presence of phosphoenolpyruvate, which conferred dramatic thermostability, KDOP synthase had a catalytic temperature optimum of about 53°C. The pH optimum was 6.2, and divalent cations were neither stimulatory nor required for activity. The Km values for arabinose 5-P and phosphoenolpyruvate were 0.27 mol m⁻³ and about 35 mmol m⁻³, respectively. The kinetics of periodate oxidation of KDOP formed by spinach KDOP synthase indicate that the same stereochemical configuration exists as with bacterial KDOP. The possibility that an unregulated species of DAHP synthase found in some bacteria might in fact be a KDOP synthase exhibiting substrate ambiguity of the type seen in higher plants was examined. However, the DAHP synthase isozyme, DS-O, from Acinetobacter calcoaceticus was found to be specific for erythrose 4-P. The KDOP synthase of Acinetobacter calcoaceticus was also found to be specific for arabinose 5-P.