Trees in paddy fields characterize the landscape of plain areas in mainland Southeast Asia. Although they play an important role in providing subsistence materials to local communities and in maintaining biodiversity, their distribution patterns are affected during agricultural intensification. In this study, we compared the density and species diversity of trees in two types of paddy fields (i.e., with and without land consolidation) to examine the effects of agricultural intensification on the woody plant community. Aerial photographs and satellite images were used to record changes in land use and tree-unit density from 1975 to 2014 at 18 target sites in three different rural landscapes. Field surveys were conducted in 2015 to investigate the total individual trees, species richness, and individual tree density. Tree species diversity was low at the local scale and varied greatly among sites, resulting in greater diversity at the landscape level. Tree species composition changed, with an increase in the number of ruderal and planted trees. During 1975-2014, the paddy plot size expanded three times due to land consolidation. As plot sizes increased, the density and species richness of remnant trees in the fields decreased, whereas planted trees on the levees were unaffected. Our results suggest that to enhance biodiversity in paddy fields, there should be a focus on improving the quality of trees planted on the levees. Smartly incorporation of various tree species onto paddy levees, together with appropriate guidelines for management of a paddy field-based agroforestry would be effective for preserving landscape sustainability.
{"title":"Reduction in woody plant diversity in paddy field landscapes during agricultural intensification in northeast Thailand","authors":"H. T. Pham, S. Miyagawa, S. Photchanachai","doi":"10.3759/TROPICS.25.13","DOIUrl":"https://doi.org/10.3759/TROPICS.25.13","url":null,"abstract":"Trees in paddy fields characterize the landscape of plain areas in mainland Southeast Asia. Although they play an important role in providing subsistence materials to local communities and in maintaining biodiversity, their distribution patterns are affected during agricultural intensification. In this study, we compared the density and species diversity of trees in two types of paddy fields (i.e., with and without land consolidation) to examine the effects of agricultural intensification on the woody plant community. Aerial photographs and satellite images were used to record changes in land use and tree-unit density from 1975 to 2014 at 18 target sites in three different rural landscapes. Field surveys were conducted in 2015 to investigate the total individual trees, species richness, and individual tree density. Tree species diversity was low at the local scale and varied greatly among sites, resulting in greater diversity at the landscape level. Tree species composition changed, with an increase in the number of ruderal and planted trees. During 1975-2014, the paddy plot size expanded three times due to land consolidation. As plot sizes increased, the density and species richness of remnant trees in the fields decreased, whereas planted trees on the levees were unaffected. Our results suggest that to enhance biodiversity in paddy fields, there should be a focus on improving the quality of trees planted on the levees. Smartly incorporation of various tree species onto paddy levees, together with appropriate guidelines for management of a paddy field-based agroforestry would be effective for preserving landscape sustainability.","PeriodicalId":51890,"journal":{"name":"Tropics","volume":"5 1","pages":"13-22"},"PeriodicalIF":0.7,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3759/TROPICS.25.13","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70003147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study reports field survey results on current tourist activities and perception regarding marine ecosystem conservation in the Nha Trang Bay Marine Protected Area (NTB-MPA), Vietnam. Structured questionnaire surveys to visitors (n ＝ 166) revealed that, comparing Vietnamese and foreign tourists: (1) About half of the Vietnamese respondents were aware of the NTB-MPA while only 9.6 % of foreign respondents recognized this, (2) average respondents visited more than two islands out of the total nine islands during their stay and Vietnamese and foreign respondents tended to visit different islands with different marine activities, and (3) of six marine conservation program components presented in the present survey, both groups showed stronger support for physical enhancement of marine ecosystems rather than for sustainable local community development with slight differences in components between the two respondent groups. These results suggest that the NTB-MPA needs to fulfill both the diverse demands of tourists as well as sustainable marine ecosystem management. However, at the same time, NTB-MPA could also offer diverse opportunities to familiarize tourists with different backgrounds in both environmental and socio-economic issues in marine ecosystems and to facilitate their support for the MPA.
{"title":"Tourists’ perception of marine ecosystem conservation in the Nha Trang Bay Marine Protected Area, Vietnam","authors":"N. Kaida, N. Dang","doi":"10.3759/TROPICS.24.187","DOIUrl":"https://doi.org/10.3759/TROPICS.24.187","url":null,"abstract":"This study reports field survey results on current tourist activities and perception regarding marine ecosystem conservation in the Nha Trang Bay Marine Protected Area (NTB-MPA), Vietnam. Structured questionnaire surveys to visitors (n ＝ 166) revealed that, comparing Vietnamese and foreign tourists: (1) About half of the Vietnamese respondents were aware of the NTB-MPA while only 9.6 % of foreign respondents recognized this, (2) average respondents visited more than two islands out of the total nine islands during their stay and Vietnamese and foreign respondents tended to visit different islands with different marine activities, and (3) of six marine conservation program components presented in the present survey, both groups showed stronger support for physical enhancement of marine ecosystems rather than for sustainable local community development with slight differences in components between the two respondent groups. These results suggest that the NTB-MPA needs to fulfill both the diverse demands of tourists as well as sustainable marine ecosystem management. However, at the same time, NTB-MPA could also offer diverse opportunities to familiarize tourists with different backgrounds in both environmental and socio-economic issues in marine ecosystems and to facilitate their support for the MPA.","PeriodicalId":51890,"journal":{"name":"Tropics","volume":"24 1","pages":"187-194"},"PeriodicalIF":0.7,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3759/TROPICS.24.187","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70002691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article explores changes in the traditional use of forests and their relationship with belief in tiger spirits in the Cardamom Mountains in southwest Cambodia. Locals inhabiting the mountains believe that spirits associated with tigers bite those who violate taboos on forest use. However, the tiger population has declined due to the wildlife trade, which experienced rapid growth during the civil war of the 1990s. The article examines the impact of the war and wildlife trade on the traditional use of the forest by analyzing the relationships among traditional beliefs, changes in the tiger population caused by the growth of the wildlife trade, and war-related changes in the social order. Before the war, beliefs associating tigers with forest use could be observed on several societal levels. The belief that tigers punish violators was practiced on village and inter-village levels, while another form of belief was also practiced on family and individual levels. However, the tiger's disappearance from the region because of the wildlife trade made such beliefs ineffective. A new belief arose that violators were punished by crop damage caused by wild pigs and other animals. Nevertheless, those who practiced the belief at the individual and family levels still believed in the association between the tiger and spirits and their role in forest use. Therefore, the impact of the aforementioned factors on tiger beliefs differed according to societal level; the extinction of living tigers does not necessarily result in the disappearance of belief at all levels of society.
{"title":"Historical change in the traditional use of forests and its association with belief in tiger spirits in the Cardamom Mountains, Cambodia: The impact of war and wildlife trade on the relationship between humans and tigers","authors":"Hiroyuki Ishibashi, M. Inoue, Motomu Tanaka","doi":"10.3759/TROPICS.24.119","DOIUrl":"https://doi.org/10.3759/TROPICS.24.119","url":null,"abstract":"This article explores changes in the traditional use of forests and their relationship with belief in tiger spirits in the Cardamom Mountains in southwest Cambodia. Locals inhabiting the mountains believe that spirits associated with tigers bite those who violate taboos on forest use. However, the tiger population has declined due to the wildlife trade, which experienced rapid growth during the civil war of the 1990s. The article examines the impact of the war and wildlife trade on the traditional use of the forest by analyzing the relationships among traditional beliefs, changes in the tiger population caused by the growth of the wildlife trade, and war-related changes in the social order. Before the war, beliefs associating tigers with forest use could be observed on several societal levels. The belief that tigers punish violators was practiced on village and inter-village levels, while another form of belief was also practiced on family and individual levels. However, the tiger's disappearance from the region because of the wildlife trade made such beliefs ineffective. A new belief arose that violators were punished by crop damage caused by wild pigs and other animals. Nevertheless, those who practiced the belief at the individual and family levels still believed in the association between the tiger and spirits and their role in forest use. Therefore, the impact of the aforementioned factors on tiger beliefs differed according to societal level; the extinction of living tigers does not necessarily result in the disappearance of belief at all levels of society.","PeriodicalId":51890,"journal":{"name":"Tropics","volume":"24 1","pages":"119-138"},"PeriodicalIF":0.7,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3759/TROPICS.24.119","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70002452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Edge effects caused by forest fragmentation may impact the growing environment of both seedlings and maternal trees. Early regeneration stages are of special concern but how maternal origin, edge effects, light environment, and distance from reproductive conspecific trees, as expected from the Janzen-Connell hypothesis, may affect seedling performance, has rarely been studied simultaneously. The goal of this study was to experimentally assess the relative importance of the aforementioned factors for seedling performance of an animal-dispersed, pioneer tree species Ficus tonduzii (Moraceae) in premontane wet forest fragments in Costa Rica. Seedlings from known maternal origins were grown in a screen house before being transplanted at two distances from focal trees in forest fragments. Both maternal trees (home) and non-maternal reproductive conspecific (away) were used as focal trees. In the screen house, seedling size and inherent growth differed by maternal origin. In the forest, distance from the nearest forest edge was the primary factor affecting survivorship and growth of transplants. Additionally, inconsistent maternal effects were observed. While seedlings from a particular maternal origin showed reduced growth in the screen house, those same seedlings showed enhanced growth once they were transplanted in the forest. In contrast, light environment or distance from the reproductive conspecific tree did not predict seedling performance. Home disadvantage was observed for one tree, which underlined the significance of seed dispersal. The results from this case study emphasize the importance of considering both edge effects and stage-specific maternal effects for successful species regeneration and restoration practices in fragmented landscapes.
{"title":"Transplant experiments reveal edge effects and inconsistent maternal effects on seedling performance in the pioneer tree Ficus tonduzii (Moraceae)","authors":"A. Sugiyama, C. Peterson","doi":"10.3759/TROPICS.24.91","DOIUrl":"https://doi.org/10.3759/TROPICS.24.91","url":null,"abstract":"Edge effects caused by forest fragmentation may impact the growing environment of both seedlings and maternal trees. Early regeneration stages are of special concern but how maternal origin, edge effects, light environment, and distance from reproductive conspecific trees, as expected from the Janzen-Connell hypothesis, may affect seedling performance, has rarely been studied simultaneously. The goal of this study was to experimentally assess the relative importance of the aforementioned factors for seedling performance of an animal-dispersed, pioneer tree species Ficus tonduzii (Moraceae) in premontane wet forest fragments in Costa Rica. Seedlings from known maternal origins were grown in a screen house before being transplanted at two distances from focal trees in forest fragments. Both maternal trees (home) and non-maternal reproductive conspecific (away) were used as focal trees. In the screen house, seedling size and inherent growth differed by maternal origin. In the forest, distance from the nearest forest edge was the primary factor affecting survivorship and growth of transplants. Additionally, inconsistent maternal effects were observed. While seedlings from a particular maternal origin showed reduced growth in the screen house, those same seedlings showed enhanced growth once they were transplanted in the forest. In contrast, light environment or distance from the reproductive conspecific tree did not predict seedling performance. Home disadvantage was observed for one tree, which underlined the significance of seed dispersal. The results from this case study emphasize the importance of considering both edge effects and stage-specific maternal effects for successful species regeneration and restoration practices in fragmented landscapes.","PeriodicalId":51890,"journal":{"name":"Tropics","volume":"24 1","pages":"91-99"},"PeriodicalIF":0.7,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3759/TROPICS.24.91","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70002963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yasuyuki Kosaka, B. Saikia, C. Rai, K. Hage, Haruhisa Asada, Tag Hui, T. Riba, K. Ando
The transformation of land from swidden based to permanent agriculture is an important issue related to the sustainable livelihood and land use system of people in mountain environments. This paper reports the introduction of paddy rice cultivation and its consequences in four swiddener communities in Arunachal Pradesh, India, by focusing on cultivation techniques. The Indian government introduced paddy rice cultivation to Arunachal Pradesh in the 1950 s by teaching the required techniques and supplying seed and agricultural tools. However, few swiddeners began rice cultivation because they disliked working in muddy paddies that could not produce non-rice crops. During the “green revolution” in the 1970 s, many people decided to create paddy fields after observing the remarkably high yield of new rice varieties. Over 60 years of trial and error, many swiddener communities have developed a unique cultivation system suited to their local environment, while often learning from their neighboring communities of Ahom and Apatani that already practiced paddy rice cultivation. The paddy field has become a symbol of wealth and social status because of the high and stable yield of paddy rice and escalating land prices. However, the communities usually continue some aspects of swidden cultivation, because only a limited amount of land is suitable for paddy rice, people need non-rice crops, or because older people prefer swidden cultivation work and the taste of upland rice. This case study shows the importance of local needs and knowledge of skilled farmers in swidden transformation.
{"title":"On the introduction of paddy rice cultivation by swiddeners in Arunachal Pradesh, India","authors":"Yasuyuki Kosaka, B. Saikia, C. Rai, K. Hage, Haruhisa Asada, Tag Hui, T. Riba, K. Ando","doi":"10.3759/TROPICS.24.75","DOIUrl":"https://doi.org/10.3759/TROPICS.24.75","url":null,"abstract":"The transformation of land from swidden based to permanent agriculture is an important issue related to the sustainable livelihood and land use system of people in mountain environments. This paper reports the introduction of paddy rice cultivation and its consequences in four swiddener communities in Arunachal Pradesh, India, by focusing on cultivation techniques. The Indian government introduced paddy rice cultivation to Arunachal Pradesh in the 1950 s by teaching the required techniques and supplying seed and agricultural tools. However, few swiddeners began rice cultivation because they disliked working in muddy paddies that could not produce non-rice crops. During the “green revolution” in the 1970 s, many people decided to create paddy fields after observing the remarkably high yield of new rice varieties. Over 60 years of trial and error, many swiddener communities have developed a unique cultivation system suited to their local environment, while often learning from their neighboring communities of Ahom and Apatani that already practiced paddy rice cultivation. The paddy field has become a symbol of wealth and social status because of the high and stable yield of paddy rice and escalating land prices. However, the communities usually continue some aspects of swidden cultivation, because only a limited amount of land is suitable for paddy rice, people need non-rice crops, or because older people prefer swidden cultivation work and the taste of upland rice. This case study shows the importance of local needs and knowledge of skilled farmers in swidden transformation.","PeriodicalId":51890,"journal":{"name":"Tropics","volume":"24 1","pages":"75-90"},"PeriodicalIF":0.7,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3759/TROPICS.24.75","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70002908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
It is important for the development of conservation projects to establish collaborative relationships with local populations, and for that, a detailed understanding of local lifestyles is required. In particular, basic information on local people’s natural resource utilization is essential. In this article, the authors analyzed livelihoods in Moukalaba-Doudou National Park (MDNP), southwestern Gabon based on quantitative data obtained from long-term field research. It was shown that people inhabiting the area around the MDNP depend heavily on natural resources for their livelihoods and they produced sufficient food within the region. However, it was also shown that the variety of food items was poor compared with other protected area in Africa and the nutritional status is presumed to have been inadequate. When compared with the data before the establishment of the National Park in 2002, consumption of bush meat decreased remarkably whereas that of fish only slightly increased after ten years. It is supposed that the people around the MDNP have converted their lifestyles flexibly to coexist with the conservation projects in a part, but it is also the fact that conservation practices threaten local livelihoods to some extent.
{"title":"Analysis of local livelihoods around Moukalaba-Doudou National Park in Gabon","authors":"Naoki Matsuura, G. Moussavou","doi":"10.3759/TROPICS.23.195","DOIUrl":"https://doi.org/10.3759/TROPICS.23.195","url":null,"abstract":"It is important for the development of conservation projects to establish collaborative relationships with local populations, and for that, a detailed understanding of local lifestyles is required. In particular, basic information on local people’s natural resource utilization is essential. In this article, the authors analyzed livelihoods in Moukalaba-Doudou National Park (MDNP), southwestern Gabon based on quantitative data obtained from long-term field research. It was shown that people inhabiting the area around the MDNP depend heavily on natural resources for their livelihoods and they produced sufficient food within the region. However, it was also shown that the variety of food items was poor compared with other protected area in Africa and the nutritional status is presumed to have been inadequate. When compared with the data before the establishment of the National Park in 2002, consumption of bush meat decreased remarkably whereas that of fish only slightly increased after ten years. It is supposed that the people around the MDNP have converted their lifestyles flexibly to coexist with the conservation projects in a part, but it is also the fact that conservation practices threaten local livelihoods to some extent.","PeriodicalId":51890,"journal":{"name":"Tropics","volume":"23 1","pages":"195-204"},"PeriodicalIF":0.7,"publicationDate":"2015-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3759/TROPICS.23.195","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70001345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many empirical studies have supported the facilitative effect of nurse plants, and several recent studies have reported similar phenomena with non-plant features, such as rocks. Few studies have explored the effect of rock height on plant establishment, although variation in height can affect establishment. This study examined whether rocky outcrops have positive effects on plant establishment, as do classic nurse plants, and explored the mechanisms involved in the nurse effects in a South African grassland. To answer these questions, we compared the number of individual woody plants at the edges of rocky outcrops and in the adjacent grassland matrix, as well as beneath a putative nurse plant (Euclea crispa) and in the adjacent grassland matrix. We also measured the heights of rocky outcrops and E. crispa and the proportions of grass cover. The results showed that larger numbers of woody seedlings occurred at the edges of rocky outcrops and beneath E. crispa compared with in the adjacent grassland matrix. A generalised linear model (GLM) showed that rock and E. crispa height positively affected the number of seedlings; the diaspores of most recorded species showed characteristics associated with dispersal by vertebrates. The GLM analysis showed that the proportion of grass cover had a negative effect on the number of seedlings. These results indicate that in addition to shrubs, rocky outcrops appear to have positive effects on the establishment of woody plants in South African grasslands, likely serving as perching structures for birds and providing favourable microhabitats.
{"title":"Role of nurse rocks on woody plant establishment in a South African grassland","authors":"Tomohiro Fujita, Kazuharu Mizuno","doi":"10.3759/TROPICS.24.57","DOIUrl":"https://doi.org/10.3759/TROPICS.24.57","url":null,"abstract":"Many empirical studies have supported the facilitative effect of nurse plants, and several recent studies have reported similar phenomena with non-plant features, such as rocks. Few studies have explored the effect of rock height on plant establishment, although variation in height can affect establishment. This study examined whether rocky outcrops have positive effects on plant establishment, as do classic nurse plants, and explored the mechanisms involved in the nurse effects in a South African grassland. To answer these questions, we compared the number of individual woody plants at the edges of rocky outcrops and in the adjacent grassland matrix, as well as beneath a putative nurse plant (Euclea crispa) and in the adjacent grassland matrix. We also measured the heights of rocky outcrops and E. crispa and the proportions of grass cover. The results showed that larger numbers of woody seedlings occurred at the edges of rocky outcrops and beneath E. crispa compared with in the adjacent grassland matrix. A generalised linear model (GLM) showed that rock and E. crispa height positively affected the number of seedlings; the diaspores of most recorded species showed characteristics associated with dispersal by vertebrates. The GLM analysis showed that the proportion of grass cover had a negative effect on the number of seedlings. These results indicate that in addition to shrubs, rocky outcrops appear to have positive effects on the establishment of woody plants in South African grasslands, likely serving as perching structures for birds and providing favourable microhabitats.","PeriodicalId":51890,"journal":{"name":"Tropics","volume":"24 1","pages":"57-64"},"PeriodicalIF":0.7,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3759/TROPICS.24.57","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70002754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I compiled a list of mediumand large-sized mammals (excluding Rodentia) in Moukalaba-Doudou National Park, Gabon. Additionally, I evaluated the efficiency of camera trapping for inventorying these animals. I placed 125 camera traps (set to “video mode”) in forest and savannah in the eastern regions of the park, and compared my data with visual and acoustic observational records from the study area since 1999. I confirmed the occurrence of 38 species (11 Primates, 13 Carnivora, nine Ungulates, and five other taxa). During 4165 camera-days, my camera traps detected 29 out of the 38 species (76 %), including 10 newly-recorded species in the study area. However, a high proportion of cameras (40 %) in savannah were destroyed by Loxodonta africana. Furthermore, using this technique, it was difficult to detect arboreal species. It was also difficult to discriminate morphologically similar species (Cephalophus spp., Phataginus spp., and Galago spp.) from the captured images. These species can be more appropriately detected by visual sighting, acoustic hearing, and molecular techniques, suggesting that a combination of these techniques may increase the inventory efficiency. The number of forest-dwelling herbivores was lower in Moukalaba than in four other sites at or near Gabon, possibly because of separation from large Pleistocene refuges by a natural boundary. Nevertheless, Moukalaba harbors two savannah-dwellers─Kobus ellipsiprymnus and Herpestes ichneumon─which inhabit only a few protected areas of Gabon. The forest is invading the savannah, and therefore there is a requirement for regular burning, which must be enforced to preserve the totality of the existing biodiversity.
{"title":"Inventorying medium- and large-sized mammals in the African lowland rainforest using camera trapping","authors":"Yoshihiro Nakashima","doi":"10.3759/TROPICS.23.151","DOIUrl":"https://doi.org/10.3759/TROPICS.23.151","url":null,"abstract":"I compiled a list of mediumand large-sized mammals (excluding Rodentia) in Moukalaba-Doudou National Park, Gabon. Additionally, I evaluated the efficiency of camera trapping for inventorying these animals. I placed 125 camera traps (set to “video mode”) in forest and savannah in the eastern regions of the park, and compared my data with visual and acoustic observational records from the study area since 1999. I confirmed the occurrence of 38 species (11 Primates, 13 Carnivora, nine Ungulates, and five other taxa). During 4165 camera-days, my camera traps detected 29 out of the 38 species (76 %), including 10 newly-recorded species in the study area. However, a high proportion of cameras (40 %) in savannah were destroyed by Loxodonta africana. Furthermore, using this technique, it was difficult to detect arboreal species. It was also difficult to discriminate morphologically similar species (Cephalophus spp., Phataginus spp., and Galago spp.) from the captured images. These species can be more appropriately detected by visual sighting, acoustic hearing, and molecular techniques, suggesting that a combination of these techniques may increase the inventory efficiency. The number of forest-dwelling herbivores was lower in Moukalaba than in four other sites at or near Gabon, possibly because of separation from large Pleistocene refuges by a natural boundary. Nevertheless, Moukalaba harbors two savannah-dwellers─Kobus ellipsiprymnus and Herpestes ichneumon─which inhabit only a few protected areas of Gabon. The forest is invading the savannah, and therefore there is a requirement for regular burning, which must be enforced to preserve the totality of the existing biodiversity.","PeriodicalId":51890,"journal":{"name":"Tropics","volume":"119 1","pages":"151-164"},"PeriodicalIF":0.7,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3759/TROPICS.23.151","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70001376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Culturing the intestinal bacteria of wild animals is a difficult task under field conditions, although isolation and characterization of bacteria are absolutely necessary to evaluate the transmission of bacteria from human to animal or vice versa. We have developed a protocol for intestinal bacteria culturing from feces of wild animals such as gorillas in Moukalaba-Doudou National Park in Gabon, where no laboratory settings were available. The prevalence of resistance genes in Enterobacteriaceae isolates estimated by real time PCR array was higher for aminoglycosides resistance, followed by tetracycline resistance, except for possible naturally occurring β-lactam resistance. The detection level of resistance genes was higher for isolates from humans than those from gorillas. Occasional monitoring of this prevalence may help to measure the intensity of introduction of humanborne bacteria to wildlife.
{"title":"Bacteria culturing and isolation under field conditions of Moukalaba-Doudou National Park, Gabon, and preliminary survey on bacteria carrying antibiotic resistance genes","authors":"P. P. M. Nguema, Sayaka Tsuchida, K. Ushida","doi":"10.3759/TROPICS.23.165","DOIUrl":"https://doi.org/10.3759/TROPICS.23.165","url":null,"abstract":"Culturing the intestinal bacteria of wild animals is a difficult task under field conditions, although isolation and characterization of bacteria are absolutely necessary to evaluate the transmission of bacteria from human to animal or vice versa. We have developed a protocol for intestinal bacteria culturing from feces of wild animals such as gorillas in Moukalaba-Doudou National Park in Gabon, where no laboratory settings were available. The prevalence of resistance genes in Enterobacteriaceae isolates estimated by real time PCR array was higher for aminoglycosides resistance, followed by tetracycline resistance, except for possible naturally occurring β-lactam resistance. The detection level of resistance genes was higher for isolates from humans than those from gorillas. Occasional monitoring of this prevalence may help to measure the intensity of introduction of humanborne bacteria to wildlife.","PeriodicalId":51890,"journal":{"name":"Tropics","volume":"23 1","pages":"165-174"},"PeriodicalIF":0.7,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3759/TROPICS.23.165","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70001646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yukako Monda, Y. Kiyono, L. Melling, Christopher Damian, Auldry Chaddy
Biomass estimations in tropical peat swamp forests are quite complex when hollow trees are frequently found due to the unavailability of data on hollow size and the limited data on accurate measures of biomass. Destructive samplings were done for both above(AGB) and belowground biomass (BGB) and hollow sizes of remained trees at a logged-over peat swamp forest in Sarawak, Malaysia. Subsequently, allometric equations taking hollows into account for both the aboveand belowground biomass of tropical peat swamp forests were also being developed. It was observed that these were hollows in Shorea albida and Combretocarpus rotundatus trees with diameters at breast height (DBH) exceeding 40 cm; S. albida is a dominant or co-dominant species, and C. rotundatus grows in peat swamp forests throughout Sarawak. The hollow volumes ranged from 0.23 to 1.08 m, and occupied 42.3% of stem volume on average. The larger biomass produced by previous allometric models were partially due to the presence of hollows. Thus, new models for estimating both AGB and BGB were developed that included one (only DBH), two (DBH and height [H] or wood density [WD]), or three (DBH, H, and WD) predictor variables, and [ln(DBH)] was added as predictor variable indicating the biomass loss by cavity formation. AGB model with three predictor variables and BGB model with one predictor variable performed the best where; they had the highest adjusted coefficients of determination and lowest Furnival index and Akaike information criterion (AIC).
热带泥炭沼泽森林的生物量估计相当复杂，因为经常发现空心树，因为没有空心大小的数据，而且关于生物量精确测量的数据有限。在马来西亚沙捞越的一个被砍伐的泥炭沼泽森林中，对剩余树木的地上(AGB)和地下生物量(BGB)以及空心大小进行了破坏性采样。随后，考虑到热带泥炭沼泽森林地上和地下生物量的空穴的异速生长方程也正在开发中。结果表明，在杉树和圆圆杉树中，树胸径大于40 cm;沙捞越的泥炭沼泽森林中均有优势种或共优势种。中空体积在0.23 ~ 1.08 m之间，平均占茎体积的42.3%。以前异速生长模型产生的较大生物量部分是由于空洞的存在。在此基础上，建立了包括1个(仅胸径)、2个(胸径加高度[H]或木材密度[WD])或3个(胸径、胸径和胸径)预测变量的AGB和BGB估算模型，并添加了[ln(DBH)]作为预测变量，表示空洞形成造成的生物量损失。三个预测变量的AGB模型和一个预测变量的BGB模型表现最好，其中;校正决定系数最高，Furnival指数和赤池信息标准(Akaike information criterion, AIC)最低。
{"title":"Allometric equations considering the influence of hollow trees: A case study for tropical peat swamp forest in Sarawak","authors":"Yukako Monda, Y. Kiyono, L. Melling, Christopher Damian, Auldry Chaddy","doi":"10.3759/TROPICS.24.11","DOIUrl":"https://doi.org/10.3759/TROPICS.24.11","url":null,"abstract":"Biomass estimations in tropical peat swamp forests are quite complex when hollow trees are frequently found due to the unavailability of data on hollow size and the limited data on accurate measures of biomass. Destructive samplings were done for both above(AGB) and belowground biomass (BGB) and hollow sizes of remained trees at a logged-over peat swamp forest in Sarawak, Malaysia. Subsequently, allometric equations taking hollows into account for both the aboveand belowground biomass of tropical peat swamp forests were also being developed. It was observed that these were hollows in Shorea albida and Combretocarpus rotundatus trees with diameters at breast height (DBH) exceeding 40 cm; S. albida is a dominant or co-dominant species, and C. rotundatus grows in peat swamp forests throughout Sarawak. The hollow volumes ranged from 0.23 to 1.08 m, and occupied 42.3% of stem volume on average. The larger biomass produced by previous allometric models were partially due to the presence of hollows. Thus, new models for estimating both AGB and BGB were developed that included one (only DBH), two (DBH and height [H] or wood density [WD]), or three (DBH, H, and WD) predictor variables, and [ln(DBH)] was added as predictor variable indicating the biomass loss by cavity formation. AGB model with three predictor variables and BGB model with one predictor variable performed the best where; they had the highest adjusted coefficients of determination and lowest Furnival index and Akaike information criterion (AIC).","PeriodicalId":51890,"journal":{"name":"Tropics","volume":"24 1","pages":"11-22"},"PeriodicalIF":0.7,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3759/TROPICS.24.11","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70002260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：