Ecology of Sandalwood (Santalum album L.) at Lingmethang, Eastern Bhutan

A study was carried out at Lingmethang to find out the ecological requirement for the growth of Sandalwood (Santalum album L.) trees in Bhutan. It also aimed to determine the preferred hosts of Sandalwood in the study site and to map its habitat suitability in the country. Plot size of 20 x 20 m2 for trees, 10 x 10 m2 for shrubs, and 5 x 5 m2 for regenerations and herbs were used. Soil samples were collected by digging soil to 25-30 cm depth from each plot. PC-ORD software was used for finding the relation of the variable with seedling abundance. A total of 19 tree species under 14 families and 40 undergrowth species under 24 families were recorded in the areas where Sandalwood is growing naturally. Mallotus philippensis and Albizia sikkimensis were the co-dominant tree species with chirpine as the dominant tree. Chromolaena odorata (Asteraceae) was the most preferred host species of the Sandalwood seedlings followed by Murraya koenigii. Mature Sandalwood tree was found parasitizing on Desmodium sp. (Fabaceae). Slope was one of the most determinant factors for the growth of Sandalwood (r = .951, p < .05), but rainfall had greater influence even though negative (r = -.943, p < .05) in the valley. Soil Nitrogen did not have much effect on the seedling abundance but mature trees prefered Fabaceae as hosts. A total of 16 dzongkhags are suitable for plantation of Sandalwood. Among these, Zhemgang Dzongkhag has the maximum potential area (469.62 km2) and Punakha Dzongkhag has the least (2.88 km2).

Phenotypic plasticity and ecology of three species of Podostemaceae Rich. Ex C. Agardh

The members of Podostemaceae, commonly called river-weeds, are with very peculiar vegetative form; revealing many unique morphological, anatomical and ecological characters from other angiosperms. They undergo an annual cycle of colonization, establishment of a canopy of mature plant, and dies back when the water level drops. The annual pattern is dictated by high and low water periods. Physico-chemical analysis showed that the largest population of the species occupied an area of full sunlight. Water samples from the two study sites viz. Janiaw and Umtienger localities, both from East Khasi Hills District, Meghalaya, India, showing high pH indicated less human activities of different kind. It is also determined that the species inhabits clean rivers, thus, they serve as an indicator of clean water. They occur primarily in low nutrient condition. Further, it was also observed that dissolved oxygen is the most essential factor for successful establishment of these plants, rather than other nutrients and pH. Toxic discharge of effluents from industries and agrochemical residues are serious threat to podostemads that has unique ecological requirement.

Contrasting pattern of photobiont diversity in the Atlantic and Pacific populations ofErioderma pedicellatum(Pannariaceae)

The present study investigates the photobiont diversity of the boreal felt lichen,Erioderma pedicellatum. Previously sampled genetic data from Newfoundland were reanalyzed and new sequence data (16S rDNA,rbcLX) of the boreal felt lichen from Alaska (USA), Kamchatka (Russia), and North Trøndelag (Norway) were generated. The highest genetic diversity of the photobiont is found in Alaska and Kamchatka, indicating that these may be the primary sources of the species in the Northern Hemisphere. In Newfoundland, the photobiont ofE. pedicellatumwas screened on leaves of the symbiotic liverwortFrullania asagrayanaand it was found to occur on trees where no other lichens were present, demonstrating that the geographical distribution, and possibly also the ecological requirement of the photobiont ofE. pedicellatum, is wider than that of the lichen phenotype. Finally, a postulated association between the occurrence of the vegetatively reproducingCoccocarpia palmicolaand the occurrence of the compatible photobiont ofE. pedicellatumon the same tree could not be established.

Epipactis hyblaea (Orchidaceae; Epidendroideae; Neottieae) a new species from Sicily

A new species of Epipactis from Sicily is described and illustrated. It shows closer relationships mainly with E. distans, species widespread in northern Mediterranean territory from SE Spain to N Croazia and also some Central and Northern European territory, with an isolated population in N Calabria. Numerous morphological features, as well as ecological requirement and phenology allow to distinguish very well the two taxa at specific level. Besides, the conservation status, habitat and a distribution map of this new species are presented.