Environmental Correlates of Distribution of the 25 Broad-leaved Tree Species Indigenous to Guangdong Province,China

Twenty-five tree species indigenous to Guangdong Province were chosen in this study to portray their distribution patterns in relation to environmental factors. Both data of species distribution and environmental factors were tabulated based on a digitized map of Guangdong Province gridded at 0.5° latitude × 0.5° longitude. Grid-based diversity was mapped using DMAP, a distribution mapping program, and horizontal patterns were assessed using Kruskal-Wallis tests. The diversity center of the indige- nous tree species under study is located north of 23° N. These tree species exhibit significant latitudinal variation (P = 0.007 4), but no significant longitudinal difference (P = 0.052 2). Non-metric Multidimensional Scaling (NMS) identified five different ecological species groups, while Canonical Correspondence Analysis (CCA) showed the distribution of tree species along each of the five envi- ronmental gradients. An understanding of the environmental correlates of distribution patterns has great implication for the introduc- tion of the indigenous tree species for afforestation.

Browse silage as potential feed for captive wild ungulates in southern Africa:A review

The objective of the review was to assess the potential of indigenous browse trees as sustainable feed supplement in the form of silage for captive wild ungulates.Several attempts to use silage as feed in zoos in temperate regions have been conducted with success.Information on silage from the indigenous browse trees preferred by wild ungulates in southern Africa is scanty.The use of silage from the browse trees is of interest as it has potential to reduce or replace expensive feed sources(pellets,fruits and farm produce) currently offered in southern African zoos,game farms and reserves,especially during the colddry season.Considerable leaf biomass from the indigenous browse trees can be produced for silage making.High nutrient content and minerals from indigenous browsable trees are highly recognised.Indigenous browse trees have low water-soluble carbohydrates(WSC) that render them undesirable for fermentation.Techniques such as wilting browse leaves,mixing cereal crops with browse leaves,and use of additives such as urea and enzymes have been studied extensively to increase WSC of silage from the indigenous browse trees.Anti-nutritional factors from the indigenous browse preferred by the wild ungulates have also been studied extensively.Indigenous browse silages are a potential feed resource for the captive wild ungulates.If the browse trees are used to make silage,they are likely to improve performance of wild ungulates in captivity,especially during the cold-dry season when browse is scarce.Research is needed to assess the feasibility of sustainable production and the effective use of silage from indigenous browse trees in southern Africa.Improving intake and nutrient utilisation and reducing the concentrations of anti-nutritional compounds in silage from the indigenous browse trees of southern Africa should be the focus for animal nutrition research that need further investigation.