Shrub height and crown diameter are useful non-destructive measures of shrub growth, but precise yields of aerial biomass require destructive methods which are unsatisfactory in studies on perennial shrubs. We developed simple regression models to predict components of aerial biomass from the height, crown diameter and volume of 27 unbrowsed shrubs of fourwing saltbush (Atriplex canescens). The shrubs, ranging in height from 15 to 110 cm, were cut at ground level and manually separated into forage (leaves) and woody material. Samples were oven-dried. Shrub height and volume were suffkiently precise for predicting components of aerial biomass using exponential and linear regression models, respectively. The precision of these non-destructive measures applied under field conditions to unbrowsed shrubs should be confirmed on browsed shrubs.
Food avoidance can be directly motivated in the sense that an animal refrains from eating a food because of an aversion to it, or indirectly motivated in the sense that an animal ingests little of one item because it prefers another. We studied whether the reluctance of a lamb to eat a shrub (Cercocarpus montanus) its mother avoided resulted from a socially induced aversion to C. montanus or from a socially induced preference for an alternative shrub (Amelanchier alnifolia). Each lamb (n = 6) in the treatment group was exposed with its mother to either A. alnifolia or C. montanus for 5 min, followed by 5 min of exposure to the other food for 5 d. Mothers in the treatment group avoided C. montanus because its ingestion had previously been paired with lithium chloride, but they readily ate A. alnifolia. Each lamb in the control group (n = 6) was exposed with its mother to only A. alnifolia. Following weaning, lambs in both groups strongly preferred A. alnifolia to C. montanus when offered a choice between the two species (P < .05), but they readily ate C. montanus when only C. montanus was offered. Accordingly, the data support the hypothesis that the low consumption of C. montanus occurred as a result of a socially induced preference for A. alnifolia, not as a result of a socially induced aversion to C. montanus. If food avoidance had been directly mediated, lambs whose mother avoided C. montanus would have completely avoided the shrub during testing, as in the case when acquired food aversions are directly mediated by toxins.
A comprehensive floristic survey of Kotli District, Azad Jammu and Kashmir was conducted during 2014-2016 to analyse phytodiversity and ecological characteristics of plant resources. The flora comprised of 202 plant species distributed among 71 families and 176 genera. Of these, 6 species were pteridophytes, 1 species was a gymnosperm, 159 species were dicotyledons and 36 species were monocotyledons. Based on species numbers, Asteraceae (23 Spp), Poaceae (20 Spp), Fabaceae (15 Spp), Labiatae (11 Spp), and Euphorbiaceae (07 Spp) were the leading families. Based on biological spectrum, therophytes (73 Spp., 36.14 %) were dominant followed by hemicryptophytes (19.31%), nanophanerophytes (13.37%), geophytes (10.40%), lianas (7.92%), chamaephytes (7.43%) and megaphanerophytes (5.45%). Nanophylls (36.14%), leptophylls (26.73%) and microphylls (26.24%) were the major leaf size classes. Phenological study revealed four different flowering seasons, with April the peak flowering month during which 122 species blossomed. This current study will provide essential baseline information for ecologists, taxonomists and conservationists to carry out more detailed ecological investigations and conservation management planning for the plant resources of this area.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.