Determining suitable locations for seed transfer under climate change: a global quantitative method

Changing climate conditions will complicate efforts to match seed sources with the environments to which they are best adapted. Tree species distributions may have to shift to match new environmental conditions, potentially requiring the establishment of some species entirely outside of their current distributions to thrive. Even within the portions of tree species ranges that remain generally suitable for the species, local populations may not be well-adapted to altered local conditions. To assist efforts to restore forests and to maximize forest productivity in the face of climate change, we developed a set of 30,000 quantitatively defined seed transfer “ecoregions” across the globe. Reflecting current and future conditions, these were created by combining global maps of potentially important environmental characteristics using a large-scale statistical clustering technique. This approach assigns every 4?km² terrestrial raster cell into an ecoregion using non-hierarchical clustering of the cells in multivariate space based on 16 environmental variables. Two cells anywhere on the map with similar combinations of environmental characteristics are located near each other in this data space; cells are then classified into relatively homogeneous ecoregion clusters. Using two global circulation models and two emissions scenarios, we next mapped the predicted environmentally equivalent future locations of each ecoregion in 2050 and 2100. We further depicted areas of decreasing environmental similarity to given ecoregions, both in current time and under climate change. This approach could help minimize the risk that trees used for production, restoration, reforestation, and afforestation are maladapted to their planting sites.     

Ultrasonography of the Collateral Ligaments of the Distal Interphalangeal Joint in Horses: Technique and Reference Images

This study describes ultrasound (US) technique and reference images of the equine distal interphalangeal joint collateral ligaments (CLs), and evaluates the portion of the CLs assessable by US in a series of normal forelimbs. Transverse and longitudinal US images were obtained on five healthy horses and on 25 equine cadaver forelimbs. On six limbs, a needle was placed under US-guidance at the distal limit of visualization of each CL, and the portion of CL visible at US was evaluated on computed tomographic (CT) images. The normal CLs appear as oval structures located abaxial to the fossae of the middle phalanx in the transverse sections, obtained at the level of the coronary band. A centrodorsal hypoechoic image appears with increasing proximodistal probe inclination, demonstrating different fiber orientations within the ligament. Two main fascicles, a deep and a superficial, distally divergent, are visible on longitudinal images obtained in the central part of the ligament. The proportion of CL visible at US examination was more than 50% of the total ligament length in nine of the 12 CLs assessed by CT. Awareness of the estimated portion of distal interphalangeal joint CLs visible at US and detailed knowledge of the US technique and CLs morphology are essential to efficiently use US examination on clinical cases.