Distribution and population status of Kingiodendron pinnatum (Angiosperms: Fabaceae) an endemic and endangered legume tree in southern Western Ghats, Kerala, India

An extensive survey and population analysis of the endemic and endangered tree Kingiodendron pinnatum, was carried out in the Kerala area of the Western Ghats. The aim was to assess the pattern of distribution, population size and natural regeneration of the species. The fragmented and patchy populations of the species are distributed in evergreen/semi evergreen habitats within an altitudinal range of 176-680m elevation. The tree attained a first layer/canopy species with a height range from 24–30m. Altogether 17 populations were identified and mapped in 13 forest locations in the region. A total of 140 adult individuals of the species were enumerated within the 13 forest locations. Natural regeneration of the species recorded from three zones among the 13 forest locations covering 21,000m2 area representing the Kerala state. The flowering trees displayed a height and dbh range of 10-30m and 85-320cm, respectively. The individuals are spatially arranged in aggregation among patchy populations. The populations are well represented by reproductive individuals with 77% and pre reproductive with 23%. Seedlings of 35.9% attained a height below 1m and 64.01% of a height above 1m. Considering the extent of distribution in the state, increase in the number of mature individuals (in addition to the enumerated area), and fair count of seedlings suggests a healthier conservation status of the species in the region. The economic and medicinal values, occurrence of isolated and fragmented populations, irregularities in the flowering and fruiting period among populations, however, extends urgent concerns over the pollination biology, detection of diverse genotypes subsequent multiplication and restoration of dwindling populations for the effective conservation and management of the species in situ.

Cold-hardiness and Deacclimation of Styrax americanus from Three Provenances

Styrax americanus Lam. (American snowbell) is a deciduous shrub or small tree seldom produced in nurseries. This species is distributed in patchy populations found mainly from Florida to southern Illinois, although a small, disjunct population exists in northern Illinois. The winter-hardiness and loss of hardiness during a period of increased temperature (deacclimation) of plants from this disjunct population may differ from those of S. americanus elsewhere. We examined cold-hardiness and deacclimation of stems of plants from the disjunct population, from southern Illinois, and from Florida. Segments of stems removed from plants grown outdoors in Ames, IA, were exposed to low-temperature ramping, and the temperature at which stems showed 50% damage (LT50) was determined by using the tissue-discoloration method. To assess deacclimation, stem segments were collected from cold-acclimated plants during winter in a minimally heated greenhouse and exposed to controlled warm temperatures for various time intervals followed by low-temperature ramping. Plants from Illinois were ≈15 °C more cold-hardy than plants from Florida in Feb. 2008. Plants from the disjunct population in northern Illinois showed less stem tip injury than did plants from southern Illinois. Deacclimation patterns were similar between plants from both Illinois populations. Plants sampled in Apr. 2009 from Florida deacclimated more rapidly than corresponding samples from Illinois, and the chilling required to overcome endodormancy increased with increasing latitude of plant origin. This research suggests that germplasm from the Illinois populations should be used in regions where the poorer hardiness and deacclimation resistance of most S. americanus would not permit survival.