Tropical rainforests in Sri Lanka are considered as biodiversity hotspots. However, their existen... more Tropical rainforests in Sri Lanka are considered as biodiversity hotspots. However, their existence is threatened by multiple climatic and anthropogenic drivers. Our objective was to assess the diversity, endemism and conservation status of these rainforests across a wide altitudinal range. We conducted a complete census of all trees having ≥ 10 cm diameter at breast height in ten one-hectare permanent sampling plots of tropical rainforests from 100 to 2200 m above mean sea level and determined altitudinal trends in tree diversity, floristic composition, endemism and conservation status of tree taxa. While community-scale tree diversity decreased with increasing altitude, substantial altitudinal differentiation of tree taxa was observed. Increasing day-night temperature difference (DTR), decreasing rainfall and increasing cumulative maximum soil water deficit (CSWDmax) with increasing altitude decreased tree diversity and the percentage of endemic species while increasing the percen...
Seeds of legumes are generally considered to have physical dormancy and to be orthodox, but most ... more Seeds of legumes are generally considered to have physical dormancy and to be orthodox, but most seed biologists are unaware of the various kinds and combinations of dormancy and storage behaviour in seeds of this family. The aim of our study was to document the dormancy and storage behaviour of seeds of 100 native and introduced tropical Fabaceae species in Sri Lanka and classify them into germination/storage behaviour categories. Moisture content (MC) was < 16% for fresh seeds of 94 species and >29% for those of six. Seeds of these six species had low tolerance for desiccation and for low temperatures. Thus, seeds of six species are non-orthodox and 94 species orthodox. Nine of the 100 species were non-dormant, and 2, 3 and 86 had physiological, physiological epicotyl and physical dormancy, respectively. Six germination/storage behaviour categories were identified among the 100 species. However, as in extratropical regions of the world, orthodox storage behaviour and physica...
] The Fabaceae consists of a large number of tropical and temperate tree species, including wild ... more ] The Fabaceae consists of a large number of tropical and temperate tree species, including wild relatives of important crops, shade trees, and important members of many plant communities. However, information on seed germination of tropical legumes is limited. In this study, basic information was collected on seed dormancy and storage behavior of 30 endemic, native, and introduced Fabaceae tree species in Sri Lanka. Seeds were collected throughout Sri Lanka. The seed moisture content (MC) and mass were determined. Germination and imbibition of intact and scarified seeds were compared. To test for recalcitrancy, seeds of species with > 15% MCs were dried to a low MC, stored at -1°C and then tested for germination. Seeds of 2 species had > 15% MCs, and drying and storage experiments confirmed that they were recalcitrant. Imbibition experiments revealed that seeds of 24 species exhibited physical dormancy (PY); however, 2 of these also produced a high proportion of nondormant se...
A study was carried out in 55 home gardens in six peripheral villages in the Northern flank of Du... more 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 m 2) quadrates and 4 small (1x1 m 2 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 m 2. 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 re...
A survey was conducted on the Pteridophytic flora of the Peradeniya University Park. Twenty sites... more A survey was conducted on the Pteridophytic flora of the Peradeniya University Park. Twenty sites representing almost all the possible and accessible areas of the University park were selected for the study. 55 species of ferns and fern-allies belonging to 39 genera and 18 families were recorded. Out of the 55 species, 10 are introduced aliens and there are no endemic species. Some possible threats to further survival of these are identified and highlighted. Suitable remedies are suggested and immediate action recommended for their in-situ conservation.
Many fern species occur in the different types of woodlands of the Hantana Range. Their diversity... more Many fern species occur in the different types of woodlands of the Hantana Range. Their diversity and distribution however has not been studied adequately. A qualitative and quantitative study was therefore done in 5 different woodland types in the Hantana Range viz; Natural Forest (NF), Mixed Woodland (MXW) , Paraserianthes Woodland (PAW), Alstonia Woodland (ALW) and Pinus Woodland (PIW) to compare the pteridophytic vegetation in these different habitats. Four 10 x 10 m2 plots were selected from each habitat and in each plot ten 1 x 1 m2 quadrats were sampled. All the fern species in each quadrate were identified and numbers of each species recorded. The floristic features were investigated by using density, importance value index, species richness, diversity indices and dominance diversity curves. Results revealed the presence of 41 species of ferns belonging to 27 genera and 14 families in these 5 different habitats. The total species count of NF showed the highest species richne...
Studies on bryophytes are very few and scanty; and further there are no active bryologists in Sri... more Studies on bryophytes are very few and scanty; and further there are no active bryologists in Sri Lanka, The present study was planned to fill the gaps of knowledge on mosses of the island to a certain extent. A survey was done to study the diversity of mosses in some selected sites at Hantana range, from June to December 2002. Three main habitats (viz. forest patch, stream side and road side) and three microhabitats within each main habitat (viz. rock surface, tree trunk and soil surface) were selected to sample mosses. A total of 468 moss samples (stream side-295, forest patch-89 and road side-84) were collected during the survey. These belong to 16 families (33%) and 26 genera (15%) out of the 48 families and the 174 genera of mosses, which have been recorded from Sri Lanka to date. The results revealed a relatively high diversity and richness of mosses in the study area.
Pinus species were used in watershed reforestation programmes since 1978 in Sri Lanka. However, d... more Pinus species were used in watershed reforestation programmes since 1978 in Sri Lanka. However, due to the public concern on negative impacts on environment and natural regeneration, reforestation programmes using Pinus were abandoned later. This study was initiated to evaluate influences of Pinus on natural regeneration and soil biodiversity relative to surrounding natural forests. Pinus caribea plantations in the hill country region were selected; understorey vegetation diversity and soil biodiversity were measured and compared with natural forests in the region. Ten dominant understorey species in Pinus plantations were selected based on their Important Value Index and screened for Vesicular-Arbuscular Mycorrhizal (VAM) associations and Mean Percentage Occurrence of VAM was compared. Understorey vegetation diversity was lower, and soil organism populations of mycorrhiza (number of spores/100 of soil), fungi (growth area/1g of soil), bacteria (growth area/1g of soil), free living ...
Sri Lanka is rich with its Bryoflora (mosses, liverworts and hornworts) even it is a small island... more 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 ...
The aim of our study was to study the dormancy type and storage behavior of Michelia champaca, si... more The aim of our study was to study the dormancy type and storage behavior of Michelia champaca, since the information available on seed germination and dormancy of M. champaca is incomplete. Seeds were collected from numerous M. champaca trees located in University of Peradeniya, Sri Lanka. Moisture content of fresh and one-month dry-stored seeds was measured. Viability of one-month dry stored and one-month low temperature (4 0C or -1 0C) stored seeds was tested to determine the seed storage behaviour. Imbibition and germination of manually scarified and non scarified seeds were studied. Effect of gibberellic acid (GA3), and gibberellic acid + manual scarification was studied to determine the seed dormancy type. Embryo lengths of seeds incubated on filter papers moistened with distilled water or 500 ppm GA3 solution were measured at 5-day intervals. Fresh seeds had about 25% moisture content suggesting that seeds may be recalcitrant and after 1 month of dry storage this was reduced t...
Tropical rainforests in Sri Lanka are considered as biodiversity hotspots. However, their existen... more Tropical rainforests in Sri Lanka are considered as biodiversity hotspots. However, their existence is threatened by multiple climatic and anthropogenic drivers. Our objective was to assess the diversity, endemism and conservation status of these rainforests across a wide altitudinal range. We conducted a complete census of all trees having ≥ 10 cm diameter at breast height in ten one-hectare permanent sampling plots of tropical rainforests from 100 to 2200 m above mean sea level and determined altitudinal trends in tree diversity, floristic composition, endemism and conservation status of tree taxa. While community-scale tree diversity decreased with increasing altitude, substantial altitudinal differentiation of tree taxa was observed. Increasing day-night temperature difference (DTR), decreasing rainfall and increasing cumulative maximum soil water deficit (CSWDmax) with increasing altitude decreased tree diversity and the percentage of endemic species while increasing the percen...
Seeds of legumes are generally considered to have physical dormancy and to be orthodox, but most ... more Seeds of legumes are generally considered to have physical dormancy and to be orthodox, but most seed biologists are unaware of the various kinds and combinations of dormancy and storage behaviour in seeds of this family. The aim of our study was to document the dormancy and storage behaviour of seeds of 100 native and introduced tropical Fabaceae species in Sri Lanka and classify them into germination/storage behaviour categories. Moisture content (MC) was < 16% for fresh seeds of 94 species and >29% for those of six. Seeds of these six species had low tolerance for desiccation and for low temperatures. Thus, seeds of six species are non-orthodox and 94 species orthodox. Nine of the 100 species were non-dormant, and 2, 3 and 86 had physiological, physiological epicotyl and physical dormancy, respectively. Six germination/storage behaviour categories were identified among the 100 species. However, as in extratropical regions of the world, orthodox storage behaviour and physica...
] The Fabaceae consists of a large number of tropical and temperate tree species, including wild ... more ] The Fabaceae consists of a large number of tropical and temperate tree species, including wild relatives of important crops, shade trees, and important members of many plant communities. However, information on seed germination of tropical legumes is limited. In this study, basic information was collected on seed dormancy and storage behavior of 30 endemic, native, and introduced Fabaceae tree species in Sri Lanka. Seeds were collected throughout Sri Lanka. The seed moisture content (MC) and mass were determined. Germination and imbibition of intact and scarified seeds were compared. To test for recalcitrancy, seeds of species with > 15% MCs were dried to a low MC, stored at -1°C and then tested for germination. Seeds of 2 species had > 15% MCs, and drying and storage experiments confirmed that they were recalcitrant. Imbibition experiments revealed that seeds of 24 species exhibited physical dormancy (PY); however, 2 of these also produced a high proportion of nondormant se...
A study was carried out in 55 home gardens in six peripheral villages in the Northern flank of Du... more 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 m 2) quadrates and 4 small (1x1 m 2 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 m 2. 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 re...
A survey was conducted on the Pteridophytic flora of the Peradeniya University Park. Twenty sites... more A survey was conducted on the Pteridophytic flora of the Peradeniya University Park. Twenty sites representing almost all the possible and accessible areas of the University park were selected for the study. 55 species of ferns and fern-allies belonging to 39 genera and 18 families were recorded. Out of the 55 species, 10 are introduced aliens and there are no endemic species. Some possible threats to further survival of these are identified and highlighted. Suitable remedies are suggested and immediate action recommended for their in-situ conservation.
Many fern species occur in the different types of woodlands of the Hantana Range. Their diversity... more Many fern species occur in the different types of woodlands of the Hantana Range. Their diversity and distribution however has not been studied adequately. A qualitative and quantitative study was therefore done in 5 different woodland types in the Hantana Range viz; Natural Forest (NF), Mixed Woodland (MXW) , Paraserianthes Woodland (PAW), Alstonia Woodland (ALW) and Pinus Woodland (PIW) to compare the pteridophytic vegetation in these different habitats. Four 10 x 10 m2 plots were selected from each habitat and in each plot ten 1 x 1 m2 quadrats were sampled. All the fern species in each quadrate were identified and numbers of each species recorded. The floristic features were investigated by using density, importance value index, species richness, diversity indices and dominance diversity curves. Results revealed the presence of 41 species of ferns belonging to 27 genera and 14 families in these 5 different habitats. The total species count of NF showed the highest species richne...
Studies on bryophytes are very few and scanty; and further there are no active bryologists in Sri... more Studies on bryophytes are very few and scanty; and further there are no active bryologists in Sri Lanka, The present study was planned to fill the gaps of knowledge on mosses of the island to a certain extent. A survey was done to study the diversity of mosses in some selected sites at Hantana range, from June to December 2002. Three main habitats (viz. forest patch, stream side and road side) and three microhabitats within each main habitat (viz. rock surface, tree trunk and soil surface) were selected to sample mosses. A total of 468 moss samples (stream side-295, forest patch-89 and road side-84) were collected during the survey. These belong to 16 families (33%) and 26 genera (15%) out of the 48 families and the 174 genera of mosses, which have been recorded from Sri Lanka to date. The results revealed a relatively high diversity and richness of mosses in the study area.
Pinus species were used in watershed reforestation programmes since 1978 in Sri Lanka. However, d... more Pinus species were used in watershed reforestation programmes since 1978 in Sri Lanka. However, due to the public concern on negative impacts on environment and natural regeneration, reforestation programmes using Pinus were abandoned later. This study was initiated to evaluate influences of Pinus on natural regeneration and soil biodiversity relative to surrounding natural forests. Pinus caribea plantations in the hill country region were selected; understorey vegetation diversity and soil biodiversity were measured and compared with natural forests in the region. Ten dominant understorey species in Pinus plantations were selected based on their Important Value Index and screened for Vesicular-Arbuscular Mycorrhizal (VAM) associations and Mean Percentage Occurrence of VAM was compared. Understorey vegetation diversity was lower, and soil organism populations of mycorrhiza (number of spores/100 of soil), fungi (growth area/1g of soil), bacteria (growth area/1g of soil), free living ...
Sri Lanka is rich with its Bryoflora (mosses, liverworts and hornworts) even it is a small island... more 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 ...
The aim of our study was to study the dormancy type and storage behavior of Michelia champaca, si... more The aim of our study was to study the dormancy type and storage behavior of Michelia champaca, since the information available on seed germination and dormancy of M. champaca is incomplete. Seeds were collected from numerous M. champaca trees located in University of Peradeniya, Sri Lanka. Moisture content of fresh and one-month dry-stored seeds was measured. Viability of one-month dry stored and one-month low temperature (4 0C or -1 0C) stored seeds was tested to determine the seed storage behaviour. Imbibition and germination of manually scarified and non scarified seeds were studied. Effect of gibberellic acid (GA3), and gibberellic acid + manual scarification was studied to determine the seed dormancy type. Embryo lengths of seeds incubated on filter papers moistened with distilled water or 500 ppm GA3 solution were measured at 5-day intervals. Fresh seeds had about 25% moisture content suggesting that seeds may be recalcitrant and after 1 month of dry storage this was reduced t...
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