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 fact...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.展开更多
Biodiversity assessment for tree species was conducted in three forest fragments ofthe Taita Hills, southeastern Kenya to compare species diversity between and within three exotic forest plantations of pine, eucalyptu...Biodiversity assessment for tree species was conducted in three forest fragments ofthe Taita Hills, southeastern Kenya to compare species diversity between and within three exotic forest plantations of pine, eucalyptus, cypress and the indigenous forests. The study sites were： Ngangao （120 ha）, Chawia （86 ha）, and Mbololo （185 ha）. A Y-plot design was used to sample 32 plots comprising of 65 subplots. At each subplot, all juvenile trees of 5 cm and above in diameter at breast height （DBH） were enumerated and recorded by species. Tree regeneration （seedlings and saplings） was tallied by species. The Shannon-Weiner Index was used to calculate species diversity and evenness. The derived Shannon’s indices were further converted into effective numbers to show the magnitude of differences in species biodiversities. To evaluate dif-ferences in species diversities, a one way ANOVA was conducted and to separate the means, Tukey＇s HSD and Duncan’s tests were used for even and uneven number of samples respectively. Jaccard’s similarity index was used to assess species similarities. There were more than 58 species whose stem densities varied between 10 and 2 000 trees per hectare.There were significant differences in species diversities between forest types and sites; the indigenous forests showed higher diversities than the exotic forests. Similarly, Chawia sites had higher species diversity than both Ngangao and Mbololo. Chawia also had a higher number of regen-erated species than the two other sites, including species such as Xymalos monospora, Rapanea melanophloeos, and Syzygium guineense, which are associated with low levels of disturbance. These findings indicate that the indigenous forest is more diverse in species as would be expected in the tropics. The high species diversity in Chawia could be accounted for by the higher levels of disturbance it underwent, unlike the two other sites. The regeneration of species associated with low levels of disturbance found in the exotic plots of Chawia show the likelihood of presence of long-term soil seed banks. The low regeneration in the exotics plots observed in Ngangao and Mbololo are likely due to the absence of seed banks since some of the plantations were established on bare land （in Ngango）, or the inherent physiology （allelopathy） of some of species repelling the regeneration of others.展开更多
Environmental degradation and deforestation in Jari Demonstration Plot needed forestation and reforestation,and the plant species selection was a key issue in the ecological recovery.Ecological information was fully c...Environmental degradation and deforestation in Jari Demonstration Plot needed forestation and reforestation,and the plant species selection was a key issue in the ecological recovery.Ecological information was fully considered regarding each species in various agro-climatic zones,altitude ranges,specific niches in different landscapes,soil preference,drought resistance and certain other important ecological factors.The species selection model represents an idea of ecological recovery and soil erosion control in the demonstration plot.展开更多
A study was conducted at two-biodivcrsity conservation areas of Northeastern Bangladesh （a part of Sylhet Forest Division） to assess the species composition, diversity and density of natural regeneration of tree spe...A study was conducted at two-biodivcrsity conservation areas of Northeastern Bangladesh （a part of Sylhet Forest Division） to assess the species composition, diversity and density of natural regeneration of tree species both indigenous and exotic species. Data were collected by stratified random quadrate method during January 2010 to July 2010. Totally 200 circular plots of 2 m〉〈2 m in size had 5 different habitat types of plants namely; forest, roadside, homestead （surrounding forest dwellers house）, fallow land and others （canals, streams and tea gardens side）, which included a total of 55 regenerating species belonging to 28 families. Meliaceae is the dominant family and shows the highest family importance value （26.3）, having six species, followed by Moraeeae （24.24）. Among the five habitat types, forest （43 species） possess the highes number of species, followed by roadside （23 species）. Total 15 exotic species among 9 families and 40 indigenous species with 24 families were recorded. For exotic species, Tectona grandis possess the highest relative density （11.7%） and relative frequency （10.5%）; Senna siamea had highest relative abundance （7.83%）. In case of indigenous species, Chickrassia tabularis possess the highest relative density （4.23%） and relative frequency （4%）; Dipterocarpus turbinatus bad the highest relative abundance （3.92%）. Tectona grandis （29.66） and Chickrassia tabularis （10.8） had the highest IVI for exotic and indigenous species respectively. Different diversity indic＇es such as Shanon-Winner diversity index,＇ species diversity index, species richness index, species evenness index, Simpson index and species dominance index, etc. were applied to quantify definite diversity. The regeneration of species associated with low levelsof disturbance was in the exotic Species. Study suggests that proper protection from human disturbances and scientific management of natural regeneration of two-study forests may lead a rich biodiversity site in the country.展开更多
Allometric models are necessary for estimating biomass in terrestrial ecosystems. Generalized allometric relationship exists for many tropical trees, but species- and region-specific models are often lacking. We devel...Allometric models are necessary for estimating biomass in terrestrial ecosystems. Generalized allometric relationship exists for many tropical trees, but species- and region-specific models are often lacking. We developed species-specific allometric models to predict aboveground biomass for 11 native tree species of the Sudanian savanna- woodlands. Diameters at the base and at breast height, with species means ranging respectively from 11 to 28 cm and 9 to 19 cm, and the height of the trees were used as predictor variables. Sampled trees spanned a wide range of sizes including the largest sizes these species can reach. As a response variable, the biomass of the trees was obtained through destructive sampling of 4 754 trees during wood harvesting. We used a stepwise multiple regression analysis with backward elimination procedure to develop models separately predicting, total biomass of the trees, stem biomass, and biomass of branches and twigs. All species- specific regression models relating biomass with measured tree dimen- sions were highly significant （p 〈 0.001）. The biomass of branches and twigs was less predictable compared to stem biomass and total biomass, although their models required fewer predictors and predictor interac- tions. The best-fit equations for total above-ground biomass and stem biomass bad R2 〉 0.70, except for the Acacia species; for branches including twig biomass, R2-values varied from 0.749 for Anogeissus leiocarpa to 0.183 for Acacia macrostachya. The use of these equations in estimating available biomass will avoid destructive sampling, and aid in planning for sustainable use of these species.展开更多
Tropical fruit trees constitute important biological resources in the global agrobiodiversity context. Unlike the tropical fruit trees of American and Asian origin, indigenous fruit trees (IFT) of tropical Africa have...Tropical fruit trees constitute important biological resources in the global agrobiodiversity context. Unlike the tropical fruit trees of American and Asian origin, indigenous fruit trees (IFT) of tropical Africa have scarcely achieved the status of international recognition in commodity markets and research arena outside Africa. This paper presented a critical review of the status of IFT in the Tropical African sub-regions (of West Africa, Central Africa, East Africa, Southern Africa and the Indian Ocean Islands) in relation to the introduced naturalised fruit trees from tropical America and Asia, threats to the diversity and sustainable use of IFT, analysis of the opportunities and challenges of developing IFT, as well as targets for crop improvement of the rich IFT of Tropical Africa. Domestication programme via relevant vegetative propagation techniques for priority IFT of the sub-regions was examined and advocated, in addition to the adoption of complementary conservation strategies, including Field GeneBanks in the management of the continent’s IFT diversity.展开更多
Fruit extracts of indigenous Melia azedarach were tested for their insecticidal bioactivity against the tomato leafminer(Tuta absoluta)under laboratory conditions.Tomato plants were exposed to moths,after/before appli...Fruit extracts of indigenous Melia azedarach were tested for their insecticidal bioactivity against the tomato leafminer(Tuta absoluta)under laboratory conditions.Tomato plants were exposed to moths,after/before application of treatments.Treatments included:crushed fruit extracts of water(500,000 ppm and 200,000 ppm),methanol and ethyl acetate(200,000 ppm)with and without mineral oil(2%);M.azedarach powder extracts(2,000 ppm)in different solvents:water,methanol,ethanol,ethyl acetate,hexane and chloroform;biorational products:neem oil,mineral oil,micronized sulfur and thyme oil.The released moths were removed from treated/untreated plants at 72 h and effect of treatments on adults,eggs,larvae and pupae were recorded.Results indicated that sulfur caused the lowest number of live moths to be present on treated plants and was not significantly different in its effect from that of M.azedarach extracts and neem oil.Aqueous extracts without and with oil caused the highest%of dry eggs and were comparable to neem oil.Extracts in the two formulations(crushed fruits and/or powder)caused significant direct effects on immature instars:eggs,early larval instars and pupae.M.azedarach extracts and the tested products also caused indirect effect in form of significant decrease in number of developing the 3rd larval instars and new emerging moths compared to the control.Consecutive sprays of these extracts against eggs,larvae and pupae on same treated plants lead to very low number of moths for a second generation of the pest which contributes to low buildup of pest population in a tomato crop.展开更多
An ethnobotanical study was carried out in the sacred forests of Kaya Kauma in Kilifi county and Kaya Tsolokero in Junju location in Kenya between 21st January 2015 to 22nd February 2016. Ethnobotanical data on the kn...An ethnobotanical study was carried out in the sacred forests of Kaya Kauma in Kilifi county and Kaya Tsolokero in Junju location in Kenya between 21st January 2015 to 22nd February 2016. Ethnobotanical data on the knowledge of useful Indigenous Food Plants among the dwelling population in the villages around Kaya Kauma and Kaya Tsolokero were obtained from the using semi-structured questionnaire and interviews of the population in the homesteads around both the forests. The Food Plants included vegetables, fruit or any sort of food if they yield to the society. Results based on a questionnaire survey in 18 villages around Kaya Kauma and 9 villages around Kaya Tsolokero are presented by different stratum of Gender, Age, Tribes, Education level, Relationship to the village, Marital status. Usage of plant as food out of the population interviewed around Kaya Kauma and the total fruit plants mentioned by the villagers dwelling around the forest was 18 belonging to 9 different families. The total vegetable plants which were mentioned by the population around Kaya Kauma were 23 belonging to 12 different families. Other Food Plants mentioned by the community was 36. Out of the population interviewed around Kaya Tsolokero out of the Food Plants mentioned by the community, total fruit plants mentioned by the community was 46 belonging to 19 different families, total vegetable plants mentioned was 20 which belonged to 13 different families and other Food Plants mentioned by the community was 23. Out of the dwelling tribes around Kaya Kanma, Mkauma emerged as the most popular tribe and Mjibana as the most popular tribe around Kaya Tsolokero. The 18 adjoining villages to Kaya Kauma were interviewed for the survey and 9 adjoining villages were interviewed adjacent to Kaya Tsolokero.展开更多
The small indigenous fish species(SIS)are harvested as ensemble of different fish species of varying size and shape.An appraisal of the abundance and biomass of fish species constituting such ensemble was carried out ...The small indigenous fish species(SIS)are harvested as ensemble of different fish species of varying size and shape.An appraisal of the abundance and biomass of fish species constituting such ensemble was carried out with samples collected from fish markets ofWest Bengal,India.The data revealed that at least 22 different fish species were present varying in numbers and species combinations.The abundance and biomass of the individual fish species was negatively correlated,indicating numerical dominance of small sized species.Logarithmic regression showed a good fit of the relative abundance(y)with the species richness(x)in the samples of SIS(y=55.72ln(x)e 77.27;r^(2)=0.940),while power regression was best fit for the relative biomass of individual fish(y)with the species richness(x)in the samples of SIS(y=24.58x^(-1.54);R^(2)=0.831).In overall both species specific and individual based biomass and abundance relationships were negatively correlated.In order to ascertain the harvest and marketability of the SIS in a judicious manner,monitoring of the fish assemblages in natural habitats is recommended.展开更多
基金Key Research Program of Guangdong Province (Grant No. 2002C20703) and Key Research Program of Guangdong Provincial Department ofForestry (Grant No. 2002-12)
文摘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.
基金supported by the Academy of Finland for the funding of the TAITATOO project
文摘Biodiversity assessment for tree species was conducted in three forest fragments ofthe Taita Hills, southeastern Kenya to compare species diversity between and within three exotic forest plantations of pine, eucalyptus, cypress and the indigenous forests. The study sites were： Ngangao （120 ha）, Chawia （86 ha）, and Mbololo （185 ha）. A Y-plot design was used to sample 32 plots comprising of 65 subplots. At each subplot, all juvenile trees of 5 cm and above in diameter at breast height （DBH） were enumerated and recorded by species. Tree regeneration （seedlings and saplings） was tallied by species. The Shannon-Weiner Index was used to calculate species diversity and evenness. The derived Shannon’s indices were further converted into effective numbers to show the magnitude of differences in species biodiversities. To evaluate dif-ferences in species diversities, a one way ANOVA was conducted and to separate the means, Tukey＇s HSD and Duncan’s tests were used for even and uneven number of samples respectively. Jaccard’s similarity index was used to assess species similarities. There were more than 58 species whose stem densities varied between 10 and 2 000 trees per hectare.There were significant differences in species diversities between forest types and sites; the indigenous forests showed higher diversities than the exotic forests. Similarly, Chawia sites had higher species diversity than both Ngangao and Mbololo. Chawia also had a higher number of regen-erated species than the two other sites, including species such as Xymalos monospora, Rapanea melanophloeos, and Syzygium guineense, which are associated with low levels of disturbance. These findings indicate that the indigenous forest is more diverse in species as would be expected in the tropics. The high species diversity in Chawia could be accounted for by the higher levels of disturbance it underwent, unlike the two other sites. The regeneration of species associated with low levels of disturbance found in the exotic plots of Chawia show the likelihood of presence of long-term soil seed banks. The low regeneration in the exotics plots observed in Ngangao and Mbololo are likely due to the absence of seed banks since some of the plantations were established on bare land （in Ngango）, or the inherent physiology （allelopathy） of some of species repelling the regeneration of others.
基金Sponsored by FAO of the United Nations under South-south Cooperation Program in Ethiopia(SSC/SPFS-FAO-ETHIOPIA-CHINA)~~
文摘Environmental degradation and deforestation in Jari Demonstration Plot needed forestation and reforestation,and the plant species selection was a key issue in the ecological recovery.Ecological information was fully considered regarding each species in various agro-climatic zones,altitude ranges,specific niches in different landscapes,soil preference,drought resistance and certain other important ecological factors.The species selection model represents an idea of ecological recovery and soil erosion control in the demonstration plot.
文摘A study was conducted at two-biodivcrsity conservation areas of Northeastern Bangladesh （a part of Sylhet Forest Division） to assess the species composition, diversity and density of natural regeneration of tree species both indigenous and exotic species. Data were collected by stratified random quadrate method during January 2010 to July 2010. Totally 200 circular plots of 2 m〉〈2 m in size had 5 different habitat types of plants namely; forest, roadside, homestead （surrounding forest dwellers house）, fallow land and others （canals, streams and tea gardens side）, which included a total of 55 regenerating species belonging to 28 families. Meliaceae is the dominant family and shows the highest family importance value （26.3）, having six species, followed by Moraeeae （24.24）. Among the five habitat types, forest （43 species） possess the highes number of species, followed by roadside （23 species）. Total 15 exotic species among 9 families and 40 indigenous species with 24 families were recorded. For exotic species, Tectona grandis possess the highest relative density （11.7%） and relative frequency （10.5%）; Senna siamea had highest relative abundance （7.83%）. In case of indigenous species, Chickrassia tabularis possess the highest relative density （4.23%） and relative frequency （4%）; Dipterocarpus turbinatus bad the highest relative abundance （3.92%）. Tectona grandis （29.66） and Chickrassia tabularis （10.8） had the highest IVI for exotic and indigenous species respectively. Different diversity indic＇es such as Shanon-Winner diversity index,＇ species diversity index, species richness index, species evenness index, Simpson index and species dominance index, etc. were applied to quantify definite diversity. The regeneration of species associated with low levelsof disturbance was in the exotic Species. Study suggests that proper protection from human disturbances and scientific management of natural regeneration of two-study forests may lead a rich biodiversity site in the country.
基金provided by Swedish International Development Cooperation Agency (Sida)
文摘Allometric models are necessary for estimating biomass in terrestrial ecosystems. Generalized allometric relationship exists for many tropical trees, but species- and region-specific models are often lacking. We developed species-specific allometric models to predict aboveground biomass for 11 native tree species of the Sudanian savanna- woodlands. Diameters at the base and at breast height, with species means ranging respectively from 11 to 28 cm and 9 to 19 cm, and the height of the trees were used as predictor variables. Sampled trees spanned a wide range of sizes including the largest sizes these species can reach. As a response variable, the biomass of the trees was obtained through destructive sampling of 4 754 trees during wood harvesting. We used a stepwise multiple regression analysis with backward elimination procedure to develop models separately predicting, total biomass of the trees, stem biomass, and biomass of branches and twigs. All species- specific regression models relating biomass with measured tree dimen- sions were highly significant （p 〈 0.001）. The biomass of branches and twigs was less predictable compared to stem biomass and total biomass, although their models required fewer predictors and predictor interac- tions. The best-fit equations for total above-ground biomass and stem biomass bad R2 〉 0.70, except for the Acacia species; for branches including twig biomass, R2-values varied from 0.749 for Anogeissus leiocarpa to 0.183 for Acacia macrostachya. The use of these equations in estimating available biomass will avoid destructive sampling, and aid in planning for sustainable use of these species.
文摘Tropical fruit trees constitute important biological resources in the global agrobiodiversity context. Unlike the tropical fruit trees of American and Asian origin, indigenous fruit trees (IFT) of tropical Africa have scarcely achieved the status of international recognition in commodity markets and research arena outside Africa. This paper presented a critical review of the status of IFT in the Tropical African sub-regions (of West Africa, Central Africa, East Africa, Southern Africa and the Indian Ocean Islands) in relation to the introduced naturalised fruit trees from tropical America and Asia, threats to the diversity and sustainable use of IFT, analysis of the opportunities and challenges of developing IFT, as well as targets for crop improvement of the rich IFT of Tropical Africa. Domestication programme via relevant vegetative propagation techniques for priority IFT of the sub-regions was examined and advocated, in addition to the adoption of complementary conservation strategies, including Field GeneBanks in the management of the continent’s IFT diversity.
文摘Fruit extracts of indigenous Melia azedarach were tested for their insecticidal bioactivity against the tomato leafminer(Tuta absoluta)under laboratory conditions.Tomato plants were exposed to moths,after/before application of treatments.Treatments included:crushed fruit extracts of water(500,000 ppm and 200,000 ppm),methanol and ethyl acetate(200,000 ppm)with and without mineral oil(2%);M.azedarach powder extracts(2,000 ppm)in different solvents:water,methanol,ethanol,ethyl acetate,hexane and chloroform;biorational products:neem oil,mineral oil,micronized sulfur and thyme oil.The released moths were removed from treated/untreated plants at 72 h and effect of treatments on adults,eggs,larvae and pupae were recorded.Results indicated that sulfur caused the lowest number of live moths to be present on treated plants and was not significantly different in its effect from that of M.azedarach extracts and neem oil.Aqueous extracts without and with oil caused the highest%of dry eggs and were comparable to neem oil.Extracts in the two formulations(crushed fruits and/or powder)caused significant direct effects on immature instars:eggs,early larval instars and pupae.M.azedarach extracts and the tested products also caused indirect effect in form of significant decrease in number of developing the 3rd larval instars and new emerging moths compared to the control.Consecutive sprays of these extracts against eggs,larvae and pupae on same treated plants lead to very low number of moths for a second generation of the pest which contributes to low buildup of pest population in a tomato crop.
文摘An ethnobotanical study was carried out in the sacred forests of Kaya Kauma in Kilifi county and Kaya Tsolokero in Junju location in Kenya between 21st January 2015 to 22nd February 2016. Ethnobotanical data on the knowledge of useful Indigenous Food Plants among the dwelling population in the villages around Kaya Kauma and Kaya Tsolokero were obtained from the using semi-structured questionnaire and interviews of the population in the homesteads around both the forests. The Food Plants included vegetables, fruit or any sort of food if they yield to the society. Results based on a questionnaire survey in 18 villages around Kaya Kauma and 9 villages around Kaya Tsolokero are presented by different stratum of Gender, Age, Tribes, Education level, Relationship to the village, Marital status. Usage of plant as food out of the population interviewed around Kaya Kauma and the total fruit plants mentioned by the villagers dwelling around the forest was 18 belonging to 9 different families. The total vegetable plants which were mentioned by the population around Kaya Kauma were 23 belonging to 12 different families. Other Food Plants mentioned by the community was 36. Out of the population interviewed around Kaya Tsolokero out of the Food Plants mentioned by the community, total fruit plants mentioned by the community was 46 belonging to 19 different families, total vegetable plants mentioned was 20 which belonged to 13 different families and other Food Plants mentioned by the community was 23. Out of the dwelling tribes around Kaya Kanma, Mkauma emerged as the most popular tribe and Mjibana as the most popular tribe around Kaya Tsolokero. The 18 adjoining villages to Kaya Kauma were interviewed for the survey and 9 adjoining villages were interviewed adjacent to Kaya Tsolokero.
文摘The small indigenous fish species(SIS)are harvested as ensemble of different fish species of varying size and shape.An appraisal of the abundance and biomass of fish species constituting such ensemble was carried out with samples collected from fish markets ofWest Bengal,India.The data revealed that at least 22 different fish species were present varying in numbers and species combinations.The abundance and biomass of the individual fish species was negatively correlated,indicating numerical dominance of small sized species.Logarithmic regression showed a good fit of the relative abundance(y)with the species richness(x)in the samples of SIS(y=55.72ln(x)e 77.27;r^(2)=0.940),while power regression was best fit for the relative biomass of individual fish(y)with the species richness(x)in the samples of SIS(y=24.58x^(-1.54);R^(2)=0.831).In overall both species specific and individual based biomass and abundance relationships were negatively correlated.In order to ascertain the harvest and marketability of the SIS in a judicious manner,monitoring of the fish assemblages in natural habitats is recommended.
