Floristic composition of homegarden systems in some villages in northern flank of Dumbara: with a special emphasis on endemic homegarden plant species

A study was carried out in 55 home gardens in six peripheral villages in the Northern flank of Dumbara Conservation Area (Knuckles) from January to April 2012. Two large (10x10 m2) quadrates and 4 small (1x1 m2) quadrates were studied in each randomly selected home garden. Individuals ≥ 2 m height and ≥ 1 cm DBH were measured and identification was done on site and further with the help of National Herbarium, Peradeniya. Total of 1,335 individual woody-perennials, 4,603 herbs were found in 11,000 m2. 152 woody-perennial species (19 endemic, 44 naturalized exotics, 35 cultivated and 52 timber) under 54 families and 56 herb species (46 medicinal) belonging to 33 families were recorded. Euphorbiaceae was the dominant family with 15 species, followed by Fabaceae (11 species), Anacardiaceae (10 species), Rutaceae (10 species), Myrtaceae (7 species), Rubiaceae (6 species), Arecaceae (6 species), Moraceae (5 species), Sapindaceae (4 species) and Zingiberaceae (4 species). Highest number of plant families (43) was recorded in Pitawala, while the lowest number of plant families recorded in Polommana (24). Based on the Important Value Index (IVI), the dominance, some species were selected to pay high priority for conservation. According to Shannon diversity values for different villages, Rathninda is the most stable and less disturbed, whereas Polommana is the most unstable and highly disturbed village. There were five endemic Anacardiaceae (56%) species (Campnosperma zeylanicum, Mangifera zeylanica, Semecarpus coriaceae, Semecarpus nigro-viridis, Semecarpus walkeri). Callophyllum trapezifolium, Garcinia quaesita (Clusiaceae), Dipterocarpus zelanicus, Shorea hulanidda (Dipterocarpaceae), Agrostistachys hookeri, Phyllanthus myrtifolius (Euphorbiaceae), Aidia gardneri, Diplospera erythrospora (Rubiaceae), Strobilanthes anceps (Acanthaceae), Canarium zeylanicum (Burseraceae), Diospyros oppositifolia (Ebanaceae); Scolopia crassipes (Flacourtiaceae) and Pandannus ceylanicas (Pandanaceae) were the other endemics reported. Preference of plant to grow in their homegardens was varied from household to household. Most are preferred on Cocus nucifera (57%) and 24% of people were interested in timber trees such as Tectona grandis, Melia azedarach, Swietenia macrophylla and Chloroxylon swietenia. Twelve percent of the studied population was preferred in fruit trees while 5% were interested in some medicinal plants. Preference of this nature indicates that the deprivation of plant diversity in the homegadens in near future. Therefore, people in northern flank of Dumbara area should be encouraged to incorporate multipurpose endemic plants and plants with less IVI values in their home gardens in order to conserve of endemic and relatively rare plants, with the facilitates of relevant authoritie

Discovery of Some Fissidens Species (Bryophyta, Fissidentaceae), New to Sri Lanka

Sri Lanka is rich with its Bryoflora (mosses, liverworts and hornworts) even it is a small island. There are 560 species of mosses in the country and Fissidentaceae is the richest monogeneric family among Sri Lankan moss flora, with 38 species of Fissidens. Fissidens is an acrocarpous moss with distichous, alternate and complanate leaves with costae (very rarely lack), size ranges from a few mm (minute bud like) to several cm (medium sized) and the presence of vaginant lamina is very characteristic to the family.Preliminary survey of mosses conducted in Hakgala Botanic Gardens, including the edge adjacent to Hakgala Strict Nature Reserve and Peradeniya Royal Botanic Gardens on August 08 and 10, 2012 respectively with special emphasis on the genus Fissidens. This study was done as a practical component of the National Workshop on Evolution, Biodiversity and Conservation of Sri Lankan Bryoflora organized and conducted by National Herbarium, Department of National Botanic Gardens, Sri Lanka (August 06-12, 2012). Random opportunistic sample collections were done, using a pair of forceps, into paper packets, after careful observations in the field using a set of hand lenses (x10, x15 & x20). Identification was done up to species level and further up to varietal level following some standard taxonomic keys and texts, using stereoscopic and light microscopes.Nine species of Fissidens were identified from the collections; Fissidens anomalus Mont., F. bryoides var. bryoides Hedw., Fissidens ceylonensis Dozy & Molk., Fissidens crenulatus Mitt., Fissidens crispulus Brid., Fissidens flaccidus Mitt., Fissidens gardneri Mitt., F. hyalinus and Fissidens taxifolius Hedw. (F. hyalinus is a species without costae). Four species out of nine have not previously been recorded from Sri Lanka, viz. F. bryoides var. bryoides, F. crenulatus F. hyalinus and F. taxifolius. Therefore, the discovery of these four new species of Fissidens is announced here for the first time, as new species for Sri Lanka. F. bryoides var. bryoides and F. hyalinus, Fissidens taxifolius recorded from Hakgala Botanic Gardens, and F. crenulatus from Peradeniya Royal Botanic Gardens. With addition of 4 new species, number Fissidens species rose to 42 and hence the number of Sri Lankan moss flora increased to 564 specieThe necessity of careful systematic collections, proper identification and determination, reporting and taking suitable measures for in situ conservation of these tiny mosses is a timely requirement. Hence, further survey of Fissidens is being conducted at present

Species Composition and Visiting Frequencies of Flower Visitors of Chromolaena odorata

Plant-animal interaction has been a major theme in ecology as it has helped ecologists to rule out different patterns they observed in the surrounding environments. Chromolaena odorata is another plant species that is studied extensively as it has become a major troublesome weed in many parts of the tropics. But, handful of studies are available on pollination of this invasive plant species in dry forests and its function as a pollinator sink in these environments. The current study was carried out in a dry zone secondary forest patch in North-Central Sri Lanka to assess the diversity, abundance, and pollination strength of flower visitors associated with the C. odorata. The results suggest that the diversity of Hymenoptera and Lepidoptera is higher than the other insect orders that visited C. odorata, but all species exerted equal pollination strength on the plant. The attraction of large numbers of insects is concluded to as one of the factors that contribute to the reproductive success of C. odorata in dry zone forests

Physiological Epicotyl Dormancy and Recalcitrant Storage Behaviour in Seeds of Two Tropical Fabaceae (Subfamily Caesalpinioideae) Species

BACKGROUND AND AIMS: Physiological epicotyl dormancy in which the epicotyl elongates inside the seed before the shoot emerges has been reported for only a few tropical rainforest species, all of which are trees that produce recalcitrant seeds. In studies on seeds of Fabaceae in Sri Lanka, we observed a considerable time delay in shoot emergence following root emergence in seeds of the introduced caesalpinioid legumes Brownea coccinea and Cynometra cauliflora. Thus, our aim was to determine if seeds of these two tropical rainforest trees have physiological epicotyl dormancy, and also if they are recalcitrant, i.e. desiccation sensitive. METHODOLOGY: Fresh seeds were (i) dried to various moisture levels, and (ii) stored at -1 and 5 °C to determine loss (or not) of viability and thus type of seed storage behaviour (orthodox, recalcitrant or intermediate). To identify the kind of dormancy, we tested the effect of scarification on imbibition and monitored radicle emergence and epicotyl growth (inside the seed) and emergence. PRINCIPAL RESULTS: FRESH SEEDS OF BOTH SPECIES HAD HIGH MOISTURE CONTENT (MC): 50 % for C. cauliflora and 30 % for B. coccinea. Further, all seeds of C. cauliflora and the majority of those of B. coccinea lost viability when dried to 15 % MC; most seeds of both species also lost viability during storage at -1 or 5 °C. Intact seeds of both species were water permeable, and radicles emerged in a high percentage of them inHowever, shoot emergence lagged behind root emergence by 77 ± 14 days in B. coccinea and by 38 ± 4 days in C. cauliflora. Further, plumule growth inside seeds of C. cauliflora began almost immediately after radicle emergence but not until ∼30-35 days in B. coccinea seeds. CONCLUSIONS: Seeds of both species are recalcitrant and have physiological epicotyl dormancy. The kind of physiological epicotyl dormancy in seeds of C. cauliflora has not been described previously; the formula is C(nd) (root)-[Formula: see text] (epicotyl)

The present status of the homegardens in Galle District of Sri Lanka affected by the December 26, 2004 Tsunami : a comparison with non-affected homegardens in connection with restoration

Der massive Tsunami im Indischen Ozean vom 26. Dezember 2004 verursachte auch in Sri Lanka katastrophale Schäden. In dieser Arbeit wird die Bedeutung der Vegetation, insbesondere von Schutzgürteln zur Abmilderung der Schäden untersucht. Untersuchungsobjekt waren von dem Tsunami betroffene Homgarden im Süden Sri Lankas. Mit Hilfe von Befragungen wurde das Ausmaß der Schäden von tsunami-betroffenen und nicht betroffenen Gärten innerhalb der ersten 100 m und 200 m von der Küste ermittelt. In 10 x 10 m Probeflächen wurden alle Holzpflanzen von mehr als 1 cm Durchmesser und mehr als 1,5 m Höhe aufgenommen. Zusätzlich wurden auch die dort üblichen lebenden Zäune untersucht. Letztendlich wurde die Präferenz der lokalen Bevölkerung für bestimmte Baumarten abgefragt. Die gegenwärtige pflanzliche Vielfalt an Holzpflanzen war in den vom Tsunam betroffenen Homegarden der küstennahen Zone am höchsten. Die Bestandesdichte hingegen in den nicht betroffen Gärten. Die Kokospalme war in allen 4 Kategorien die häufigste Baumart. Die floristische Vielfalt der Verjüngung von Holzpflanzen war im küstenfernen, vom Tsunami betroffenen Bereich am höchsten, während die Diversität im nicht betroffenen, küstenfernen Bereich am höchsten war. Die Evenness war in den nicht betroffenen küstennahen Gärten am höchsten. Für die lebenden Zäune werden sowohl einheimische als auch fremdländische Holzpflanzen verwendet. Der Anteil an einheimischen Küstenpflanzen ist ein wichtiger Aspekt. Die Bewohner hatten sehr klare Vorstellungen über den Nutzen und die Verwendbarkeit verschiedener Gehölze. Von den 15 untersuchten Arten ist die Kokosnuss am beliebtesten und wird wegen der vielfältigen Nutzbarkeit auch bei der Wiederherstellung verwüsteter Gärten bevorzugt. Aber auch Bäume die Holz für den Bootsbau oder Möbel liefern werden wieder gepflanzt, obwohl sie lange Zeit bis zur Nutzbarkeit benötigen.On December 26, 2004, the massive Asian Tsunami caused catastrophic damage to the community and environment of Sri Lanka. Role of vegetation in mitigating the effect of tsunami and establishment of a green belt were highlighted. A study was conducted from 2006-2008, in tsunami affected homegardens in Southern Sri Lanka. A questionnaire survey was done to investigate the impact of the tsunami. Then, I compared the vegetation of tsunami affected homegardens with non-affected homegardens in the 100m belt and in the 100-200m belt from the shoreline. Woody perennials 1cm DBH and 1.5m height were identified and counted in one 10mx10m plot from each homegarden. Seedlings of woody perennials <1cm DBH and <1.5m height were identified and counted using one 1mx1m quadrats within each 10mx10m quadrat. Then, the composition of live fences around homegardens was studied qualitatively. Finally, surveyed the uses of selected 15 plant species and investigate the preference of integrating them by the coastal community. Questionnaire survey revealed some valuable information on the damage caused by tsunami on homegardens. Floristic richness of tree species was highest in the homegardens of the tsunami affected 100m belt, density was highest in the non-affected 100m belt, total basal area was highest in tsunami affected 100m belt, while the mean DBH was highest in the affected 100m belt. Tree diversity and evenness were highest in the homegardens of the non-affected 200m belt. Floristic richness of seedlings of tree species was highest in the homegardens of the tsunami-affected100m belt, while the density was highest affected 200m belt. Diversity of seedlings of tree species was highest in the homegardens of the non-affected 200m belt, while the evenness of seedlings of woody perennial plants was highest in the non-affected 100m belt. The live fences around the coastal homegardens comprised of both native and exotic plant species and abundance of native coastal species in live fences is an important feature. Some plant species had a high demand for various purposes and some others were considered as less important by the community. Key words: Sri Lanka, tsunami, coastal community, homegardens, vegetation, impactssubmitted by Wijetunga Mudiyanselage Gamagedara Asanga Sanjeeva Tikiri Bandara WijetungaAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in dt. SpracheWien, Univ. für Bodenkultur, Diss., 2008OeBB(VLID)193023

Variation of floristic diversity, community composition, endemism, and conservation status of tree species in tropical rainforests of Sri Lanka across a wide altitudinal gradient

Abstract Tropical rainforests in Sri Lanka are biodiversity hotspots, which are sensitive to anthropogenic disturbance and long-term climate change. We assessed the diversity, endemism and conservation status of these rainforests across a wide altitudinal range (100–2200 m above sea level) via a complete census of all trees having ≥ 10 cm diameter at breast height in ten one-hectare permanent sampling plots. The numbers of tree families, genera and species and community-scale tree diversity decreased with increasing altitude. Tree diversity, species richness and total basal area per ha across the altitudinal range were positively associated with long-term means of maximum temperature, annual rainfall and solar irradiance. Percentage of endangered species increased with increasing altitude and was positively associated with cumulative maximum soil water deficit, day-night temperature difference and high anthropogenic disturbance. Percentage of endemic species was greater in the lowland rainforests than in high-altitude montane forests. Nearly 85% of the species were recorded in three or less plots, which indicated substantial altitudinal differentiation in their distributions. Less than 10 individuals were recorded in 41% of the endemic species and 45% of the native species, which underlined the need for urgent conservation efforts across the whole altitudinal range