Species-specific responses to environmental stress on germination and juvenile growth of two Bolivian Andean agroforestry species

Integrating native trees in farmland can support soil, water and biodiversity conservation. This is particularly important in regions characterized by long periods of drought and soil erosion, such as the Bolivian Andes, where agroforestry with native woody species is rarely applied. Better knowledge on the effects of environmental stress on propagation and establishment of such native plants is needed to optimize their cultivation. In our study, we tested the effects of temperature and scarification on seed germination, and assessed seedling survival and juvenile growth of two potential agroforestry species (Prosopis laevigata var. andicola, Schinus molle) under diverse soil and water conditions. Temperatures above 30 °C accelerated germination, but they increased fungi infestation in the case of S. molle. The application of acid and mechanical scarification significantly improved the germination capacity of P. laevigata var. andicola. Medium to high moisture levels in sand provided the most favourable conditions for plant growth. S. molle was more sensitive to dry and P. laevigata var. andicola more vulnerable to water-saturated clay loam. Mulching enhanced the survival and growth of S. molle juveniles, but increased P. laevigata var. andicola’s growth in sand and dry soils only. Our results may facilitate guidance on improving propagation of these two potential agroforestry species under environmental stress conditions. More generally, our study shows that easily applicable treatments, such as mulching, can significantly improve the cultivation of native species, provided that their habitat requirements and limiting factors are well known. This highlights the relevance of identifying and closing such knowledge gaps for native trees and shrubs in order to promote their potential for use in agroforestry.     

THE USE OF "TAGGED" DERIVATIVES IN THE FLUORIMETRIC ASSAY OF VITAMINS

In a study of the Konig reaction, it was found that nicotinic acid, on reacting with CNBr and certain substituted aromatic amines, yields glutaconic dialdehyde derivatives which fluoresce with a greenish-yellow light in visible violet light of about 440 millimicrons wave-length. A procedure was described which is applicable to 0.1 to 6 micrograms in 5 cc of solution or extract. It is suggested that the principle of preparing fluorescing "tagged" derivatives be applied to other vitamins of the B-complex.     

Ossifying fibroma as a cause of blindness in a 5-year-old Quarter Horse gelding

A 5-year-old Quarter Horse gelding presented to Texas A&M University Veterinary Medical Teaching Hospital with a several week history of bilateral blindness. Neurological deficits included an absent menace response and severe atrophy of the optic nerve head in the left eye (OS) as well as decreased vision in the right eye (OD). Advanced imaging consisting of computed tomography (CT) and magnetic resonance imaging (MRI) confirmed a large mass in the base of the skull invading the sinuses and asymmetrically compressing the optic nerves rostral to the optic chiasm. Due to the size and location of the mass as well as severity of associated neurological signs, humane euthanasia was elected. Necropsy examination identified a large mass effacing the sphenopalatine sinuses and compressing the optic nerves. Histologically, the mass was identified as an ossifying fibroma (OF) and degeneration of the optic nerves was confirmed. As an OF in this location has never been described in a horse, this case demonstrates a new differential for blindness in horses.     

Shift in nesting ground of the long-legged buzzard (Buteo rufinus) in Judea, Israel – An effect of habitat change

Until the 1980s, at least 31 pairs of long-legged buzzards (Buteo rufinus) nested along the streams of the Judean Mountains in Israel, mostly on rocky cliffs, which – according to existing literature – is the common nesting style of this bird. During the past 40 years, however, nesting in these areas has substantially decreased, with many pairs of buzzards now nesting on trees in the Judean Foothills.We suggest that the geographical shift in nesting area, and with it the dramatic change from nesting on cliffs to nesting on trees, is probably due to the increase in land cover (as a result of afforestation, expansion of human settlements and recovery of the Mediterranean chaparral) that has taken place in the Judean Mountains during the last four decades. Buzzards forage in open habitats and the change in land cover has hindered their ability to locate prey. Since there are no cliffs appropriate for nesting in the Judean Foothills, the buzzards were thus forced to adapt to a new style of nesting. This hypothesis is further supported by our observations that within their new nesting grounds in the Judean Foothills, breeding success was significantly related to the area of the open habitat within the territory.These findings have important scientific and ecological implications. We recommend that foresters should take into consideration the effect of afforestation on open-landscape raptors, and while planning new forests will consider also their needs, particularly leaving large open swaths of land as foraging grounds for such raptors.