Is the Effect of Forest Structure on Bird Diversity Modified by Forest Productivity?

Currently, the most common strategy when managing forests for biodiversity at the landscape scale is to maintain structural complexity within stands and provide a variety of seral stages across landscapes. Advances in ecological theory reveal that biodiversity at continental scales is strongly influenced by available energy (i.e., climate factors relating to heat and light and primary productivity). This paper explores how available energy and forest structural complexity may interact to drive biodiversity at a regional scale. We hypothesized that bird species richness exhibits a hump-shaped relationship with energy at the regional scale of the northwestern United States. As a result, we hypothesized that the relationship between energy and richness within a landscape is positive in energy-limited landscapes and flat or decreasing in energy-rich landscapes. Additionally, we hypothesized that structural complexity explains less of the variation in species richness in energy-limited environments and more in energy-rich environments and that the slope of the relationship between structural complexity and richness is greatest in energy-rich environments. We sampled bird communities and vegetation across seral stages and biophysical settings at each of five landscapes arrayed across a productivity gradient from the Pacific Coast to the Rocky Mountains within the five northwestern states of the contiguous United States. We analyzed the response of richness to structural complexity and energy covariates at each landscape. We found that (1) richness had a hump-shaped relationship with available energy across the northwestern United States, (2) the landscape-scale relationships between energy and richness were positive or hump shaped in energy-limited locations and were flat or negative in energy-rich locations, (3) forest structural complexity explained more of the variation in bird species richness in energy-rich landscapes, and (4) the slope of the relationship between forest structural complexity and richness was steepest in energy-limited locations. In energy-rich locations, forest managers will likely increase landscape-scale bird diversity by providing a range of forest structural complexity across all seral stages. In low-energy environments, bird diversity will likely be maximized by managing local high-energy hotspots judiciously and adjusting harvest intensities in other locations to compensate for slower regeneration rates

A comparison of Power Doppler with conventional sonographic imaging for the evaluation of renal artery stenosis

BACKGROUND: Power Doppler (PD) has improved diagnostic capabilities of vascular sonography, mainly because it is independent from the angle of insonation. We evaluated this technique in a prospective comparison with conventional imaging, consisting in Duplex and Color Doppler, for the evaluation of Renal Artery (RA) stenosis. METHODS: Sensitivity, specificity and predictive values of PD and conventional imaging were assessed in a blinded fashion on eighteen patients, 9 with angiographic evidence of unilateral RA stenosis (hypertensive patients) and 9 with angiographically normal arteries (control group). PD images were interpreted with an angiography-like criteria. RESULTS: In the control group both techniques allowed correct visualization of 16 out of the 18 normal arteries (93% specificity). Only in five hypertensive patients RA stenosis was correctly identified with conventional technique (56% sensitivity and 86% negative predictive value); PD was successful in all hypertensive patients (100% sensitivity and negative predictive value), since the operators could obtain in each case of RA stenosis a sharp color signal of the whole vessel with a clear "minus" at the point of narrowing of the lumen. All results were statistically significant (p < 0.01). CONCLUSIONS: This study demonstrates that PD is superior to conventional imaging, in terms of sensitivity and specificity, for the diagnosis of RA stenosis, because it allows a clear visualization of the whole stenotic vascular lumen. Especially if it is used in concert with the other sonographic techniques, PD can enable a more accurate imaging of renovascular disease with results that seem comparable to selective angiography

Meta-analysis of the detection of plant pigment concentrations using hyperspectral remotely sensed data

Passive optical hyperspectral remote sensing of plant pigments offers potential for understanding plant ecophysiological processes across a range of spatial scales. Following a number of decades of research in this field, this paper undertakes a systematic meta-analysis of 85 articles to determine whether passive optical hyperspectral remote sensing techniques are sufficiently well developed to quantify individual plant pigments, which operational solutions are available for wider plant science and the areas which now require greater focus. The findings indicate that predictive relationships are strong for all pigments at the leaf scale but these decrease and become more variable across pigment types at the canopy and landscape scales. At leaf scale it is clear that specific sets of optimal wavelengths can be recommended for operational methodologies: total chlorophyll and chlorophyll a quantification is based on reflectance in the green (550–560nm) and red edge (680–750nm) regions; chlorophyll b on the red, (630–660nm), red edge (670–710nm) and the near-infrared (800–810nm); carotenoids on the 500–580nm region; and anthocyanins on the green (550–560nm), red edge (700–710nm) and near-infrared (780–790nm). For total chlorophyll the optimal wavelengths are valid across canopy and landscape scales and there is some evidence that the same applies for chlorophyll a

Nieuwe wegen in de chirurgische behandeling der longtuberculose

Wanneer wij trachten uit de literatuurstudie en het onderzochte patientenmateriaal conclusies te trekken, dan kunnen deze als volgt worden samengevat: I. De door Sauerbruch aangegeven totale paravertebrale thoracoplastiek met korte ribsecties is een verouderde methode, welke geen recht van bestaan meer heeft. Zie:

Marbled Murrelet nest site selection at three fine spatial scales

We implemented a unique tree-climbing effort to examine nesting-habitat selection of Marbled Murrelets (Brachyramphus marmoratus) in managed forest stands of Washington and Oregon during 1996-1999. Researchers climbed over 3000 trees to search for old and active murrelet nests during the breeding season (May-Sept.) in a random sample of stands known to be occupied by murrelets. Within these stands, characteristics of murrelet nest sites and non-nest sites were measured at three fine spatial scales: nest limb or platform, nest tree, and nest-site or forest patch (0.5 ha). We report results of a Bayesian hierarchical logistic regression model using three covariates at each of the three fine spatial scales. All three branch/platform scale covariates positively predicted nest occupancy with higher probabilities of nesting occurring at branches/platforms with higher horizontal cover, larger platform diameters, and higher moss cover. Tree scale characteristics associated with higher probabilities of nesting included higher platform counts and higher moss depth. Effect of tree diameter on probability of nesting was unclear. At the patch scale, lower probability of nesting occurred for stands with higher densities of trees with platforms. This unexpected relationship may be due in part to decreasing likelihood of observing a nest on a given platform when there are more platforms in a patch. Variation in tree size and percent canopy cover at the patch scale showed no clear association with nest selection at the patch scale. The prevalence of nests in Dwarf Mistletoe-infected hemlock trees may have partially obfuscated the effect of tree diameter on probability of encountering a nest in portions of our study area. Fine scale conservation efforts for Marbled Murrelets may include recruiting or retaining trees with larger numbers of platforms, large branches with high percentages of moss cover and horizontal cover, and younger trees with platforms created by Dwarf Mistletoe deformities

DataS2

Douglas-fir dat