Since terrestrial invertebrates are often consumed by stream fishes, land-use practices that influence the input of terrestrial invertebrates to streams are predicted to have consequences for fish production . We studied the effect of riparian land-use regime on terrestrial invertebrate inputs by estimating the biomass, abundance and taxonomic richness of terrestrial invertebrate drift from 15 streams draining catchments with three different riparian land-use regimes and vegetation types : intensive grazing -exotic pasture grasses (4 streams), extensive grazing -native tussock grasses (6 streams), reserve -native forest (5 streams) . Terrestrial invertebrate drift was sampled from replicated stream reaches enclosed by two 1 mm mesh drift nets that spanned the entire channel . The mean biomass of terrestrial invertebrates that entered tussock grassland (12 mg ash-free dry mass m-2 d -1 ) and forest streams (6 mg AFDM m -2 d`1 ) was not significantly different (p > 0 .05) . However, biomass estimated for tussock grassland and forest streams was significantly higher than biomass that entered pasture streams (1 mg AFDM m -2 d-1 ) . Mean abundance and richness of drifting terrestrial invertebrates was not significantly different among land-use types . Winged insects contributed more biomass than wingless invertebrates to both pasture and tussock grassland streams . Winged and wingless invertebrates contributed equally to biomass entering forest streams . Land use was a useful variable explaining landscape-level patterns of terrestrial invertebrate input for New Zealand streams . Evidence from this study suggests that riparian land-use regime will have important influences on the availability of terrestrial invertebrates to stream fishes .
Whole-stream drift from stream reaches enclosed by 1 mm mesh barriers was sampled to estimate the potential contribution of terrestrial invertebrates to trout production in a high-country pasture stream in New Zealand. Invertebrates were classified into two activity groups: winged or wingless. Biomass of winged insects was significantly related to temperature but not discharge. Biomass of wingless invertebrates was not related to temperature or discharge; however, abundance was significantly related to discharge but not temperature. These results suggest that mode of entry differed between activity groups. Winged insects apparently entered the stream as a function of overall activity, whereas wingless invertebrates entered the stream passivelypossibly a result of fluctuations in discharge. An empirical model based on these relationships indicated that total input of terrestrial invertebrates may support as much as 5% of annual production by resident brown trout.
The food-web communities of two stony tributaries of the Taieri River in New Zealand were documented. We placed heavy emphasis on algal and macroinvertebrate taxonomy, identifying most taxa to species or morpho-species level. Food-web attributes were derived from symmetrical matrices using an Excel macro. The values of the food-web attributes are generally consistent with generalities that have previously been reported in food-web studies, although some hypothesisied relationships between connectance and food-web size did not hold. The patterns detected were robust to the inclusion or exclusion of species that were identified in gut contents but not in field samples. The attributes strongly reflected the trophic status of the streams. †
We describe the construction and operation of an x-ray beam size monitor (xBSM), a device measuring e + and e − beam sizes in the CESR-TA storage ring using synchrotron radiation. The device can measure vertical beam sizes of 10 − 100 µm on a turn-by-turn, bunch-by-bunch basis at e ± beam energies of ∼ 2 GeV. At such beam energies the xBSM images x-rays of ≈1-10 keV (λ ≈ 0.1 − 1 nm) that emerge from a hard-bend magnet through a single-or multiple-slit (coded aperture) optical element onto an array of 32 InGaAs photodiodes with 50 µm pitch. Beamlines and detectors are entirely in-vacuum, enabling single-shot beam size measurement down to below 0.1 mA (2.5 × 10 9 particles) per bunch and inter-bunch spacing of as little as 4 ns. At E b = 2.1 GeV, systematic precision of ∼ 1 µm is achieved for a beam size of ∼ 12 µm; this is expected to scale as ∝ 1/σ b and ∝ 1/E b . Achieving this precision requires comprehensive alignment and calibration of the detector, optical elements, and x-ray beam. Data from the xBSM have been used to extract characteristics of beam oscillations on long and short timescales, and to make detailed studies of low-emittance tuning, intra-beam scattering, electron cloud effects, and multi-bunch instabilities.
Synthetic gene drive approaches are nascent technologies with potential applicability for pest control for conservation purposes. Responsible science mandates that society be engaged in a dialogue over new technology, particularly where there exist global ramifications as with gene drive. We hypothesize that public attitudes towards gene drive are not formed on scientific knowledge or demographics alone, but are heavily influenced by underlying worldviews, which encapsulate a broad and interactive system of attitudes, beliefs, and values. To test this, we conducted a national survey in New Zealand (n = 8199) and found that respondents clustered into four distinct segments with underlying worldviews, better able to explain attitudes toward gene drive than either the participants' scientific knowledge or other explanatory factors such demographics, political ideology or religiosity. We found that the use of gene drive for biodiversity conservation currently has moderate (32%) levels of support in New Zealand but that varied substantially across the four segments. Should gene drive become a technically viable approach for pest control, understanding the worldviews that shape public decision-making can guide a more empathetic engagement process and empower society to participate in informed decisionmaking about if and how gene drive should be used for conservation purposes. ARTICLE HISTORY
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