Pub Date : 2023-08-29DOI: 10.1017/S0266467423000214
B. O. Kankam, Prosper Antwi-Bosiako, L. Addae‐Wireko, Christopher Dankwah
Abstract The population of critically endangered white-thighed colobus monkeys (Colobus vellerosus) at Boabeng-Fiema Monkey Sanctuary (BFMS) is possibly the only growing population of this species in West Africa. We assessed the current population status of C. vellerosus in BFMS and the surrounding fragments in Ghana. We undertook a complete count of the population in 2020, and this data was combined with previously conducted complete counts from 1990 to 2014. Results show that the total population growth rate of colobus monkeys at BFMS and the surrounding forest fragments was 353.9% between the 1990 and 2020 censuses (at a rate of 11.8% annually). In the BFMS alone, the total population growth rate was 252.3% between 1990 and 2020 (i.e., at a rate of 8.4% annually). The total population growth rate in the surrounding forest fragments was 97.0% between the first census year of 1997 and the 2020 census (i.e., at a rate of 4.2% annually). The mean group size in the BFMS was 16.7 individuals (SD = 4.0; range = 9–25), while that of the surrounding forest fragments was 14.4 individuals (SD = 4.6; range = 9–23). The overall mean group size was 16.1 individuals (SD = 4.3; range = 9–25). An approximate ratio of one adult male to three adult females (1:3.4) and one adult female to one immature (1:1.2) is an indication that the population of C. vellerosus still has the potential to increase further when new suitable forest fragments are explored in the future. C. vellerosus has the potential to increase further in population in small, suitable fragments if habitat destruction and settlement expansion are managed with primate conservation intentions.
{"title":"Growing population of the critically endangered white-thighed colobus monkey (Colobus vellerosus) from forest fragments in Ghana","authors":"B. O. Kankam, Prosper Antwi-Bosiako, L. Addae‐Wireko, Christopher Dankwah","doi":"10.1017/S0266467423000214","DOIUrl":"https://doi.org/10.1017/S0266467423000214","url":null,"abstract":"Abstract The population of critically endangered white-thighed colobus monkeys (Colobus vellerosus) at Boabeng-Fiema Monkey Sanctuary (BFMS) is possibly the only growing population of this species in West Africa. We assessed the current population status of C. vellerosus in BFMS and the surrounding fragments in Ghana. We undertook a complete count of the population in 2020, and this data was combined with previously conducted complete counts from 1990 to 2014. Results show that the total population growth rate of colobus monkeys at BFMS and the surrounding forest fragments was 353.9% between the 1990 and 2020 censuses (at a rate of 11.8% annually). In the BFMS alone, the total population growth rate was 252.3% between 1990 and 2020 (i.e., at a rate of 8.4% annually). The total population growth rate in the surrounding forest fragments was 97.0% between the first census year of 1997 and the 2020 census (i.e., at a rate of 4.2% annually). The mean group size in the BFMS was 16.7 individuals (SD = 4.0; range = 9–25), while that of the surrounding forest fragments was 14.4 individuals (SD = 4.6; range = 9–23). The overall mean group size was 16.1 individuals (SD = 4.3; range = 9–25). An approximate ratio of one adult male to three adult females (1:3.4) and one adult female to one immature (1:1.2) is an indication that the population of C. vellerosus still has the potential to increase further when new suitable forest fragments are explored in the future. C. vellerosus has the potential to increase further in population in small, suitable fragments if habitat destruction and settlement expansion are managed with primate conservation intentions.","PeriodicalId":49968,"journal":{"name":"Journal of Tropical Ecology","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44422580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-10DOI: 10.1017/S0266467423000135
Meredith C. Swartwout, J. Willson
Abstract To understand mechanisms behind enigmatic declines of tropical reptiles, knowledge of species interactions and how they vary over space and time is important. Some tropical lizard population dynamics can be highly influenced by egg survival. Yet relatively few studies have examined relationships between lizard reproductive success and egg predators across forest and microhabitat types. In this study, we examined variation in probability of egg depredation, predatory ant abundance, prey availability, and the number of lizards and eggs encountered across four different forest types (abandoned agroforestry, abandoned plantation, secondary forest, and old-growth forest) and three microhabitats (buttress, fallen log, and leaf-litter) at La Selva Biological Station, Costa Rica. Based on previous studies, we made three hypotheses about how lizard egg abundance, egg survival, and predatory ant numbers would be related across microhabitat and forest type. Of these hypotheses, only one was supported: we found more lizard eggs in buttress and fallen log microhabitats than leaf-litter. We did not observe any differences in lizard reproduction or numbers of invertebrates by forest type alone. Based on patterns observed in this study, we suggest that future studies investigating tropical leaf-litter lizard declines focus on environmental variation at the microhabitat scale.
{"title":"Factors influencing tropical lizard reproduction vary by microhabitat but not forest type","authors":"Meredith C. Swartwout, J. Willson","doi":"10.1017/S0266467423000135","DOIUrl":"https://doi.org/10.1017/S0266467423000135","url":null,"abstract":"Abstract To understand mechanisms behind enigmatic declines of tropical reptiles, knowledge of species interactions and how they vary over space and time is important. Some tropical lizard population dynamics can be highly influenced by egg survival. Yet relatively few studies have examined relationships between lizard reproductive success and egg predators across forest and microhabitat types. In this study, we examined variation in probability of egg depredation, predatory ant abundance, prey availability, and the number of lizards and eggs encountered across four different forest types (abandoned agroforestry, abandoned plantation, secondary forest, and old-growth forest) and three microhabitats (buttress, fallen log, and leaf-litter) at La Selva Biological Station, Costa Rica. Based on previous studies, we made three hypotheses about how lizard egg abundance, egg survival, and predatory ant numbers would be related across microhabitat and forest type. Of these hypotheses, only one was supported: we found more lizard eggs in buttress and fallen log microhabitats than leaf-litter. We did not observe any differences in lizard reproduction or numbers of invertebrates by forest type alone. Based on patterns observed in this study, we suggest that future studies investigating tropical leaf-litter lizard declines focus on environmental variation at the microhabitat scale.","PeriodicalId":49968,"journal":{"name":"Journal of Tropical Ecology","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47975356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-08DOI: 10.1017/S0266467423000172
Toshihiro Yamada, Chihro Oshige, Miyabi Nakabayashi, T. Okuda, Aung Zaw Moe, E. Hlaing
Abstract Bamboos are mainly distributed in subtropical to tropical areas. Bamboos provide numerous ecosystem services, while the expansion of bamboo gives negative impacts on forest ecosystems. Despite big impacts of bamboos on a forest ecosystem, ecological characteristics of bamboo remain poorly understood. The spatial distributional patterns of three bamboo species, Cephalostachyum pergracile, Bambusa polymorpha, and Dinochloa maclellandii, were studied in a commercial tree plantation of native deciduous tree species in the Bago Mountains, Myanmar. A point process analysis revealed a clumped distribution for each bamboo species. The distributional overlapping of the species was analysed for every pair of two species. The distribution of C. pergracile was little overlapped with those of D. maclellandii and B. polymorpha. Cephalostachyum pergracile was significantly more abundant on gently sloping ridges, whereas D. maclellandii was more abundant on a steeply sloping site. Bambusa polymorpha did not show these patterns with topography. The exclusive distribution of C. pergracile and D. maclellandii may be, at least partly, explained by the opposite topographic preferences of the species. Cephalostachyum pergracile tended to be found far from large trees that cast shade, although B. polymorpha tended to be found with large trees, suggesting that B. polymorpha may be more shade tolerant than C. pergracile. The difference in shade tolerance may contribute to the exclusive distribution of the species. The habitat preference information obtained in this study will contribute to sound bamboo management practices in Myanmar and enable bamboo population sizes to be increased through creation of favourable habitats in forests.
{"title":"Spatial association of bamboos with trees in a commercial tree plantation forest in Myanmar","authors":"Toshihiro Yamada, Chihro Oshige, Miyabi Nakabayashi, T. Okuda, Aung Zaw Moe, E. Hlaing","doi":"10.1017/S0266467423000172","DOIUrl":"https://doi.org/10.1017/S0266467423000172","url":null,"abstract":"Abstract Bamboos are mainly distributed in subtropical to tropical areas. Bamboos provide numerous ecosystem services, while the expansion of bamboo gives negative impacts on forest ecosystems. Despite big impacts of bamboos on a forest ecosystem, ecological characteristics of bamboo remain poorly understood. The spatial distributional patterns of three bamboo species, Cephalostachyum pergracile, Bambusa polymorpha, and Dinochloa maclellandii, were studied in a commercial tree plantation of native deciduous tree species in the Bago Mountains, Myanmar. A point process analysis revealed a clumped distribution for each bamboo species. The distributional overlapping of the species was analysed for every pair of two species. The distribution of C. pergracile was little overlapped with those of D. maclellandii and B. polymorpha. Cephalostachyum pergracile was significantly more abundant on gently sloping ridges, whereas D. maclellandii was more abundant on a steeply sloping site. Bambusa polymorpha did not show these patterns with topography. The exclusive distribution of C. pergracile and D. maclellandii may be, at least partly, explained by the opposite topographic preferences of the species. Cephalostachyum pergracile tended to be found far from large trees that cast shade, although B. polymorpha tended to be found with large trees, suggesting that B. polymorpha may be more shade tolerant than C. pergracile. The difference in shade tolerance may contribute to the exclusive distribution of the species. The habitat preference information obtained in this study will contribute to sound bamboo management practices in Myanmar and enable bamboo population sizes to be increased through creation of favourable habitats in forests.","PeriodicalId":49968,"journal":{"name":"Journal of Tropical Ecology","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42460455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-10DOI: 10.1017/S0266467423000202
A. Farji-Brener, Débora Elías Díaz, Isabelle Holanda, Andrés Sierra Ricaurte, Kenneth Barrantes, Pablo José Gutiérrez-Campos
Abstract Hypotheses based on allocation theory and herbivore selection offer opposite predictions about how defence levels against herbivores change as the plant tissue grows. The growth differentiation balance hypothesis (GDBH) assumes that defences will be resource-limited in immature tissues and predict that defence levels increase as the plant tissue grows. Conversely, the optimal defence hypothesis (ODH) proposes that plants would have the highest level of defences in the parts that have the highest value in terms of fitness and/or are more frequently attacked by herbivores, such as young tissues. We examine whether spinescence in the shrub Rubus adenotrichos (blackberry) change as the leaf grows, and if this change is consistent with the GDBH or the ODH. We compare the petiole area occupied by prickles, the prickles density and the individual prickle area in mature versus young petioles from Rubus adenotrichos. Our results show that, in R. adenotrichos, young tissues are more protected than mature tissues. Prickles density and the petiole area occupied by prickles were up to 25% higher in young petioles than in mature ones. These results support the ODH, reinforcing the idea that extrinsic factors such as herbivores pressure might drive the change of structural defences level across leaf ontogeny.
{"title":"Changes in spinescence across leaf ontogeny support the optimal defence hypothesis in blackberries (Rubus adenotrichos)","authors":"A. Farji-Brener, Débora Elías Díaz, Isabelle Holanda, Andrés Sierra Ricaurte, Kenneth Barrantes, Pablo José Gutiérrez-Campos","doi":"10.1017/S0266467423000202","DOIUrl":"https://doi.org/10.1017/S0266467423000202","url":null,"abstract":"Abstract Hypotheses based on allocation theory and herbivore selection offer opposite predictions about how defence levels against herbivores change as the plant tissue grows. The growth differentiation balance hypothesis (GDBH) assumes that defences will be resource-limited in immature tissues and predict that defence levels increase as the plant tissue grows. Conversely, the optimal defence hypothesis (ODH) proposes that plants would have the highest level of defences in the parts that have the highest value in terms of fitness and/or are more frequently attacked by herbivores, such as young tissues. We examine whether spinescence in the shrub Rubus adenotrichos (blackberry) change as the leaf grows, and if this change is consistent with the GDBH or the ODH. We compare the petiole area occupied by prickles, the prickles density and the individual prickle area in mature versus young petioles from Rubus adenotrichos. Our results show that, in R. adenotrichos, young tissues are more protected than mature tissues. Prickles density and the petiole area occupied by prickles were up to 25% higher in young petioles than in mature ones. These results support the ODH, reinforcing the idea that extrinsic factors such as herbivores pressure might drive the change of structural defences level across leaf ontogeny.","PeriodicalId":49968,"journal":{"name":"Journal of Tropical Ecology","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48239386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-05DOI: 10.1017/S0266467423000196
Davi Borges das Chagas, A. Rapini, P. M. Villa, R. Collevatti
Abstract Fire plays a crucial role in shaping plant communities in South American savannas. However, the impact of biotic interactions on tree communities still needs to be better explored. In this study, we evaluated the influence of tree-on-tree interactions and abiotic conditions on the structure and diversity of woody communities in savannas of Central Brazil. We used plots of 10 × 10 m in three preservation areas of savanna to assess the abundance and composition of juveniles and adults in woody communities associated with two Apocynaceae tree species: Hancornia speciosa, postulated to show negative interactions with the associated tree community, and Himatanthus obovatus, postulated to show positive interactions. Our results revealed that while abiotic factors, represented by the altitude, are more critical in shaping the community of juvenile trees, tree-on-tree interactions have a stronger influence on adult tree populations, driving community dynamics during plant recruitment. Specifically, Hancornia speciosa reduces the abundance of adults, whereas Himatanthus obovatus enhances their relative abundance; both shape the composition of tree communities. Consequently, tree-on-tree interactions create distinct mosaics at various stages of regeneration, contributing to savanna dynamics and conservation.
{"title":"The effect of tree-on-tree interactions and abiotic conditions on woody communities in Brazilian savannas","authors":"Davi Borges das Chagas, A. Rapini, P. M. Villa, R. Collevatti","doi":"10.1017/S0266467423000196","DOIUrl":"https://doi.org/10.1017/S0266467423000196","url":null,"abstract":"Abstract Fire plays a crucial role in shaping plant communities in South American savannas. However, the impact of biotic interactions on tree communities still needs to be better explored. In this study, we evaluated the influence of tree-on-tree interactions and abiotic conditions on the structure and diversity of woody communities in savannas of Central Brazil. We used plots of 10 × 10 m in three preservation areas of savanna to assess the abundance and composition of juveniles and adults in woody communities associated with two Apocynaceae tree species: Hancornia speciosa, postulated to show negative interactions with the associated tree community, and Himatanthus obovatus, postulated to show positive interactions. Our results revealed that while abiotic factors, represented by the altitude, are more critical in shaping the community of juvenile trees, tree-on-tree interactions have a stronger influence on adult tree populations, driving community dynamics during plant recruitment. Specifically, Hancornia speciosa reduces the abundance of adults, whereas Himatanthus obovatus enhances their relative abundance; both shape the composition of tree communities. Consequently, tree-on-tree interactions create distinct mosaics at various stages of regeneration, contributing to savanna dynamics and conservation.","PeriodicalId":49968,"journal":{"name":"Journal of Tropical Ecology","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44889009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-04DOI: 10.1017/S0266467423000184
N. L. Devi, F. Brearley, S. Tripathi
Abstract Analysing phenological diversity of tropical trees provides a potential tool to detect climate change effects and devise forest management options. In this study, the leaf phenological activity of 28 dominant tree species in a moist sub-tropical hill forest of north-eastern India was examined for a period of 2 years and related to functional traits (i.e. leaf mass per area (LMA) and wood density (WD)). The peak phase of leaf fall occurred in the cool dry period (November to January) with leaf flush peaking in the pre-monsoon period (February to March), but variation was found between species as influenced by their phenological strategy, i.e. evergreen, leaf-exchanging or deciduous (<4 months leafless). Photoperiod and minimum temperature were the environmental factors most strongly correlated with phenological activity, and the synchrony index within species for both phenophases was 0.81. LMA was less in the deciduous species compared with the evergreen species, whereas WD did not differ. LMA was negatively correlated with the length of deciduousness as well as timing of leaf flush and fall indicating that LMA may be more important than WD in influencing phenological patterns in this forest. The study revealed that the phenological diversity of tropical trees is related to changes in environmental variables and has implication for forest management under changing climate. Further study will help in understanding the phenological response of trees to climatic factors and their potential future changes.
{"title":"Phenological diversity among sub-tropical moist forest trees of north-eastern India","authors":"N. L. Devi, F. Brearley, S. Tripathi","doi":"10.1017/S0266467423000184","DOIUrl":"https://doi.org/10.1017/S0266467423000184","url":null,"abstract":"Abstract Analysing phenological diversity of tropical trees provides a potential tool to detect climate change effects and devise forest management options. In this study, the leaf phenological activity of 28 dominant tree species in a moist sub-tropical hill forest of north-eastern India was examined for a period of 2 years and related to functional traits (i.e. leaf mass per area (LMA) and wood density (WD)). The peak phase of leaf fall occurred in the cool dry period (November to January) with leaf flush peaking in the pre-monsoon period (February to March), but variation was found between species as influenced by their phenological strategy, i.e. evergreen, leaf-exchanging or deciduous (<4 months leafless). Photoperiod and minimum temperature were the environmental factors most strongly correlated with phenological activity, and the synchrony index within species for both phenophases was 0.81. LMA was less in the deciduous species compared with the evergreen species, whereas WD did not differ. LMA was negatively correlated with the length of deciduousness as well as timing of leaf flush and fall indicating that LMA may be more important than WD in influencing phenological patterns in this forest. The study revealed that the phenological diversity of tropical trees is related to changes in environmental variables and has implication for forest management under changing climate. Further study will help in understanding the phenological response of trees to climatic factors and their potential future changes.","PeriodicalId":49968,"journal":{"name":"Journal of Tropical Ecology","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48579301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-15DOI: 10.1017/S0266467423000160
Renuka Vinod Chimankare, Subhra Das, Karamjit Kaur, Dhiraj B. Magare
Abstract Greenhouses are inflated structures with transparent covering that are used to grow crops under controlled climatic conditions. Crops are protected from extreme climate-related events by being enclosed. Furthermore, the greenhouse design ratio impacts the temperature and humidity distribution profile uniformity as well as the greenhouse. As a result, by effectively designing the greenhouse structure, building materials, dimensions, and shapes, the cost of cooling management strategies can be reduced. Structures with changed arch shapes showed to be more effective at reducing greenhouse cooling demands in hot areas. To demonstrate the tropical region’s inherent capabilities for generating a proper atmosphere for plant development, the optimal temperature, humidity, light, and PH for greenhouse production of crops were supplied. Greenhouse cooling systems are dominated by local environmental characteristics that have an immediate impact on their indoor climatic conditions. Photovoltaic systems in greenhouses have proven technological capacity in real-world settings in this area. This could increase the energy efficiency of some agrivoltaic greenhouse design options.
{"title":"A review study on the design and control of optimised greenhouse environments","authors":"Renuka Vinod Chimankare, Subhra Das, Karamjit Kaur, Dhiraj B. Magare","doi":"10.1017/S0266467423000160","DOIUrl":"https://doi.org/10.1017/S0266467423000160","url":null,"abstract":"Abstract Greenhouses are inflated structures with transparent covering that are used to grow crops under controlled climatic conditions. Crops are protected from extreme climate-related events by being enclosed. Furthermore, the greenhouse design ratio impacts the temperature and humidity distribution profile uniformity as well as the greenhouse. As a result, by effectively designing the greenhouse structure, building materials, dimensions, and shapes, the cost of cooling management strategies can be reduced. Structures with changed arch shapes showed to be more effective at reducing greenhouse cooling demands in hot areas. To demonstrate the tropical region’s inherent capabilities for generating a proper atmosphere for plant development, the optimal temperature, humidity, light, and PH for greenhouse production of crops were supplied. Greenhouse cooling systems are dominated by local environmental characteristics that have an immediate impact on their indoor climatic conditions. Photovoltaic systems in greenhouses have proven technological capacity in real-world settings in this area. This could increase the energy efficiency of some agrivoltaic greenhouse design options.","PeriodicalId":49968,"journal":{"name":"Journal of Tropical Ecology","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42492035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-09DOI: 10.1017/S0266467423000159
V. J. Jaramillo, G. Murray-Tortarolo, A. Martínez-Yrizar, M. Maass, J. Sarukhán, M. Nava-Mendoza, Raúl Ahedo-Hernández, Salvador Araiza
Abstract Long-term climate and vegetation data were used to determine the role of rainfall variability and its seasonal distribution on litterfall nutrients. Based on a 20-year data set on rainfall (range 334–1,506 mm per year) and litterfall nutrients from old-growth tropical dry forest (TDF) in Mexico, we examined litterfall N and P concentrations from the rainy and dry seasons in response to rainfall in the rainy (June–October) and the dry (November–May) seasons, the latter referred to as out-of-season precipitation (OSP). Rainy-season litterfall N concentrations, but not P concentrations nor N:P ratios, changed positively (p < 0.001) in response to rainy-season precipitation. Dry-season litterfall N concentrations and N:P ratios, but not litterfall P, increased (p ≤ 0.02) in response to rainfall from the preceding rainy season. N:P ratios of dry-season litterfall in years with OSP were higher only during dry years and N concentrations decreased in wet years (p < 0.05). The narrow range in dry-season litterfall P concentrations (1.00–1.15 mg g-1), irrespective of rainfall amount and OSP, suggests P conservation. The variation in litterfall N, but not litterfall P, in response to rainfall variability reveals a divergent nutrient response along steep changes in water availability in this TDF.
{"title":"Divergent litterfall nutrient responses to rainfall seasonality revealed through long-term observations in a tropical dry forest","authors":"V. J. Jaramillo, G. Murray-Tortarolo, A. Martínez-Yrizar, M. Maass, J. Sarukhán, M. Nava-Mendoza, Raúl Ahedo-Hernández, Salvador Araiza","doi":"10.1017/S0266467423000159","DOIUrl":"https://doi.org/10.1017/S0266467423000159","url":null,"abstract":"Abstract Long-term climate and vegetation data were used to determine the role of rainfall variability and its seasonal distribution on litterfall nutrients. Based on a 20-year data set on rainfall (range 334–1,506 mm per year) and litterfall nutrients from old-growth tropical dry forest (TDF) in Mexico, we examined litterfall N and P concentrations from the rainy and dry seasons in response to rainfall in the rainy (June–October) and the dry (November–May) seasons, the latter referred to as out-of-season precipitation (OSP). Rainy-season litterfall N concentrations, but not P concentrations nor N:P ratios, changed positively (p < 0.001) in response to rainy-season precipitation. Dry-season litterfall N concentrations and N:P ratios, but not litterfall P, increased (p ≤ 0.02) in response to rainfall from the preceding rainy season. N:P ratios of dry-season litterfall in years with OSP were higher only during dry years and N concentrations decreased in wet years (p < 0.05). The narrow range in dry-season litterfall P concentrations (1.00–1.15 mg g-1), irrespective of rainfall amount and OSP, suggests P conservation. The variation in litterfall N, but not litterfall P, in response to rainfall variability reveals a divergent nutrient response along steep changes in water availability in this TDF.","PeriodicalId":49968,"journal":{"name":"Journal of Tropical Ecology","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47132058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-05DOI: 10.1017/S0266467423000111
V. J. Reiss-Woolever, Andreas Dwi Advento, A. A. K. Aryawan, J. Caliman, W. Foster, M. Naim, Pujianto, Dedi Purnomo, Jake L. Snaddon, Soeprapto, Suhardi, R. S. Tarigan, R. Wahyuningsih, Tuani Dzulfikar Siguga Rambe, Sudharto Ps., R. Widodo, S. Luke, E. C. Turner
Abstract Oil palm is one of Southeast Asia’s most common crops, and its expansion has caused substantial modification of natural habitats and put increasing pressure on biodiversity. Rising global demand for vegetable oil, coupled with oil palm’s high yield per unit area and the versatility of the palm oil product, has driven the expansion of oil palm agriculture in the region. Therefore, it is critical to identify management practices that can support biodiversity in plantations without exacerbating negative impacts on the environment. This study focuses on day-flying Lepidoptera (butterflies and moths), which contribute to the ecosystem functioning as pollinators, prey, and herbivore species. We assessed whether density and behaviours of day-flying Lepidoptera varied between different habitats within oil palm plantations and across seasons. We surveyed the density and behaviours of Lepidoptera communities in mature industrial oil palm plantations within the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme sites, in Riau, Indonesia. We surveyed two distinct habitats within the plantations in March and September 2013: Edge habitats, which were bordered by plantation roads on one side, and Core habitats in the centre of oil palm planting blocks. We conducted analyses on the effect of habitat type and season on both the overall density and behaviour of Lepidoptera communities and, independently, on the most common species. In our surveys, we observed 1464 individuals across 41 species, with a significantly higher density in Edge than in Core habitats. While there was no significant difference between overall density in March and September surveys, there was an interaction between season and habitat, with density increasing more markedly in Edge than Core areas in September. There was also a significant effect of habitat and season on behavioural time budget for the community as a whole, with more active behaviours, such as foraging and mating, being recorded more frequently in Edge than Core habitats, and more commonly in September than March. The effect of habitat type, season, and their interaction differed between the six most common species. Our findings indicate that Lepidoptera abundance is affected by habitat characteristics in a plantation and can therefore be influenced by plantation management practices. In particular, our study highlights the value of road edges and paths in plantations for day-flying Lepidoptera. We suggest that increased non-crop vegetation in these areas, achieved through reduced clearing practices or planting of flowering plants, could foster abundant and active butterfly communities in plantations. These practices could form part of sustainability management recommendations for oil palm, such as those of the Roundtable on Sustainable Palm Oil.
{"title":"Habitat heterogeneity supports day-flying Lepidoptera in oil palm plantations","authors":"V. J. Reiss-Woolever, Andreas Dwi Advento, A. A. K. Aryawan, J. Caliman, W. Foster, M. Naim, Pujianto, Dedi Purnomo, Jake L. Snaddon, Soeprapto, Suhardi, R. S. Tarigan, R. Wahyuningsih, Tuani Dzulfikar Siguga Rambe, Sudharto Ps., R. Widodo, S. Luke, E. C. Turner","doi":"10.1017/S0266467423000111","DOIUrl":"https://doi.org/10.1017/S0266467423000111","url":null,"abstract":"Abstract Oil palm is one of Southeast Asia’s most common crops, and its expansion has caused substantial modification of natural habitats and put increasing pressure on biodiversity. Rising global demand for vegetable oil, coupled with oil palm’s high yield per unit area and the versatility of the palm oil product, has driven the expansion of oil palm agriculture in the region. Therefore, it is critical to identify management practices that can support biodiversity in plantations without exacerbating negative impacts on the environment. This study focuses on day-flying Lepidoptera (butterflies and moths), which contribute to the ecosystem functioning as pollinators, prey, and herbivore species. We assessed whether density and behaviours of day-flying Lepidoptera varied between different habitats within oil palm plantations and across seasons. We surveyed the density and behaviours of Lepidoptera communities in mature industrial oil palm plantations within the Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Programme sites, in Riau, Indonesia. We surveyed two distinct habitats within the plantations in March and September 2013: Edge habitats, which were bordered by plantation roads on one side, and Core habitats in the centre of oil palm planting blocks. We conducted analyses on the effect of habitat type and season on both the overall density and behaviour of Lepidoptera communities and, independently, on the most common species. In our surveys, we observed 1464 individuals across 41 species, with a significantly higher density in Edge than in Core habitats. While there was no significant difference between overall density in March and September surveys, there was an interaction between season and habitat, with density increasing more markedly in Edge than Core areas in September. There was also a significant effect of habitat and season on behavioural time budget for the community as a whole, with more active behaviours, such as foraging and mating, being recorded more frequently in Edge than Core habitats, and more commonly in September than March. The effect of habitat type, season, and their interaction differed between the six most common species. Our findings indicate that Lepidoptera abundance is affected by habitat characteristics in a plantation and can therefore be influenced by plantation management practices. In particular, our study highlights the value of road edges and paths in plantations for day-flying Lepidoptera. We suggest that increased non-crop vegetation in these areas, achieved through reduced clearing practices or planting of flowering plants, could foster abundant and active butterfly communities in plantations. These practices could form part of sustainability management recommendations for oil palm, such as those of the Roundtable on Sustainable Palm Oil.","PeriodicalId":49968,"journal":{"name":"Journal of Tropical Ecology","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49165725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-26DOI: 10.1017/S0266467423000123
J. M. Kimeu, G. Mwachala, D. Hattas, T. Reichgelt, A. M. Muasya
Abstract A trade-off between structural and chemical defences against herbivory in woody plants is alleged to depend on edaphic factors in African savannas. We studied anti-herbivory traits, in an edaphic mosaic of fertile and infertile soils within a savanna landscape in East Africa, towards elucidating herbivory defence traits expressions in woody plants of African savannas. We used data of 81 plants for 8 species from 8 sites — four sites from fertile soils (42 plants) and another four sites from infertile soils (39 plants). We did not find a general divide between structural and chemical strategies in our data. Instead, we found a range of defence traits combinations. Our results highlight that in woody plants of African savannas, chemical and structural defences can augment each other, and not necessarily trade-off. The diversity of herbivores, ranging from insects to mesobrowsers, may have driven the evolution of multiple defence strategies within the African savannas.
{"title":"Plant defence traits among discrete vegetation assemblages in a mesic savanna landscape in Kenya","authors":"J. M. Kimeu, G. Mwachala, D. Hattas, T. Reichgelt, A. M. Muasya","doi":"10.1017/S0266467423000123","DOIUrl":"https://doi.org/10.1017/S0266467423000123","url":null,"abstract":"Abstract A trade-off between structural and chemical defences against herbivory in woody plants is alleged to depend on edaphic factors in African savannas. We studied anti-herbivory traits, in an edaphic mosaic of fertile and infertile soils within a savanna landscape in East Africa, towards elucidating herbivory defence traits expressions in woody plants of African savannas. We used data of 81 plants for 8 species from 8 sites — four sites from fertile soils (42 plants) and another four sites from infertile soils (39 plants). We did not find a general divide between structural and chemical strategies in our data. Instead, we found a range of defence traits combinations. Our results highlight that in woody plants of African savannas, chemical and structural defences can augment each other, and not necessarily trade-off. The diversity of herbivores, ranging from insects to mesobrowsers, may have driven the evolution of multiple defence strategies within the African savannas.","PeriodicalId":49968,"journal":{"name":"Journal of Tropical Ecology","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47339755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}