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Mazlan Abd Ghaffar - One of the best experts on this subject based on the ideXlab platform.
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Spatial and Temporal Variations in Strombus Canarium (Gastropoda: Strombidae) Abundance at Merambong Seagrass Bed, Malaysia (Variasi Reruang dan Temporal bagi Kelimpahan Strombus Canarium (Gastropoda: Strombidae)
2016Co-Authors: Sains Malaysiana, Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Di Hamparan Rumput Laut Merambong, Mazlan Abd GhaffarAbstract:The abundance of marine benthic organisms often exhibits distinct distributional patterns, which is generally governed by many physical and biological factors specific to the habitat. In this study, the spatial and temporal variations in abundance of the dog conch, Strombus Canarium Linnaeus 1758, a commercially important marine gastropod, was investigated. Assessment of conch abundance at Merambong seagrass bed, Malaysia, was conducted using a transect belt method. Sampling stations were randomly selected and environmental parameters associated with the habitat were recorded. The species showed distinct spatial distributional pattern. Conch densities were significantly higher in sheltered areas, mainly in mixed seagrass bed dominated by Halophila spp. and with high sediment organic content. The densities were relatively very low in areas dominated by the tape seagrass, Enhalus acoroides. The species studied also showed distinct temporal variation in abundance. The abundance value was seasonally varied with highest density recorded during the wet monsoon season (p<0.05). The densities were otherwise very low during the dry season, except for a slight peak in July. Since the conch is a very important fishery species within the Johor Straits and regulations on their harvesting is still lacking, this information would be very important for their sustainable management
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metamorphosis induction of the dog conch strombus Canarium gastropoda strombidae using cues associated with conch nursery habitat
Journal of Applied Sciences, 2010Co-Authors: Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Wan Mohd. Lotfi Wan Muda, Mazlan Abd GhaffarAbstract:Strombus Canarium is a commercially important gastropod that has great potential for advancement into aquaculture. In this study, the metamorphosis response of Strombus Canarium larvae to various metamorphosis cues associated with conch nursery habitat and to KCl and GABA, were tested. Bioassays were run as static, no choice experiment and adopting a continuous exposure approach. Strombus Canarium larvae showed strong metamorphosis responses when sediment (i.e., conch nursery habitat sediment/SD-NU) and detrital substrata (i.e., Thalassia detritus leachate/T-LC) from their nursery habitat were used (p<0.05). There was no metamorphosis in treatments using sterilized conch nursery habitat sediment (SD-ST) and sediment taken from outside conch nursery habitat (SD-OT). Experiments using fresh macrophyte blades of Enhalus acoroides (EA), Thalassia hemprichii (TH), Halophila ovalis (HA) and Ulva (UL) and adult conditioned seawater (SD-SW) also showed negative respond. Conch larvae demonstrate active habitat selection during metamorphosis and no spontaneous metamorphosis was observed. Settlement in S. Canarium is associative in nature where epibionts associated with conch nursery habitat could be the cue for the metamorphosis. However, the specific epibionts/inducers and mechanisms underlining the process were not studied and therefore are subjected to more detailed investigation. The use of KCl was comparable with treatments using natural inducers (SD-NU and T-LC), thus was suggested for application in hatchery spat production of the species.
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age growth mortality and population structure of strombus Canarium gastropoda strombidae variations in male and female sub populations
Journal of Applied Sciences, 2009Co-Authors: Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Mazlan Abd GhaffarAbstract:The age, growth, mortality and population structure of Strombus Canarium Linnaeus, 1758 were examined in the Johor Straits, Malaysia from January to December 2005. A total of 2088 conchs were sampled where females were more abundant than males with monthly sex ratio of 1.72±0.17 (N = 12). The estimated growth parameter showed higher asymptotic length (L∞) and growth coefficient (K) in females (L∞ = 70.20 mm, K = 1.50 year-1) compared with the males (L∞ = 69.30 mm, K = 1.20 year-1). This resulted in better overall growth performance of females (φ’ = 3.81) compared with the males (φ’ = 3.48). The growth pattern of females and males showed positive allometric nature of growth (b>3, p<0.05), with estimated maximum life span of 2.0 and 2.5 year, respectively. The recruitment pattern was continuous, displaying only a single major peak event per year. The estimated natural mortality rate (M) was 0.95 year-1 in females and 0.86 year-1 in males, while the total mortality rate (Z) was 2.56 and 2.72 year-1, respectively. The fishing mortality rate (F) was 1.61 year-1 in females and 1.86 year-1 in males, which were higher than the natural mortality rates, thus indicating an unbalanced position of the stock. In addition, the exploitation rate (E) was higher than the maximum allowable limit of exploitation (EMSY), which was a further indication of overexploitation. For sustainable utilization of the resource, serious efforts should immediately be taken in reducing the exploitation rates of S. Canarium in the study area.
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species description and distribution of strombus mollusca strombidae in johor straits and its surrounding areas
Sains Malaysiana, 2009Co-Authors: Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Mazlan Abd GhaffarAbstract:A total of 230 individuals of Strombus were sampled at various locations along the Johor Straits, Malaysia. There were four species of Strombus present in the study areas i.e. Strombus Canarium Linnaeus, 1758; Strombus urceus Linnaeus, 1758; Strombus marginatus subspecies succinctus Linnaeus, 1767; Strombus marginatus subspecies robustus Sowerby, 1874; and Strombus vittatus subspecies vittatus Linnaeus, 1758. Strombus Canarium was the most common, widely distributed and most abundant, followed by S. urceus, while the others were only rarely found. Among the species Strombus marginatus and Strombus vittatus were two new distribution records for the Johor Straits. Since all Strombus were traditionally harvested and consumed by the locals since long ago, further studies are needed particularly regarding the population dynamics and fishery of the harvested species.
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Development and growth of larvae of the dog conch, Strombus Canarium (Mollusca: Gastropoda), in the laboratory
Zoological Studies, 2009Co-Authors: Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Mazlan Abd Ghaffar, Wan Mohd. Lotfi Wan MudaAbstract:Development and growth of larvae of the dog conch, Strombus Canarium (Mollusca: Gastropoda), in the laboratory. Zoological Studies 48(1): 1-11. Strombus Canarium egg masses used in this study were collected while still underneath spawning females, and embryonic and post-hatching larval development was observed in the laboratory. Strombus Canarium larvae were reared at 200 larvae/L in 2-L containers with 0.22 μm filtered seawater medium at a salinity of 30 ± 1 PSU, and fed a single algal species, lsochrysis galbana, at 1000 cells/ml. Fecundity was estimated at 48,745 + 877 to 93,643 + 1685 (n = 10) eggs/egg mass. The incubation time was between 110.4 and 134.4 h (mean 122.43 + 3.07 h, n = 7) at 29 ± 1°C, with a high hatching rate (mean 93.34% ± 1.68% hatched, n = 3). The larvae have 2 velar lobes and 1.5 shell whorls at the time of hatching, with an average shell length of 216.77 ± 5.72 μm (n = 10). Based on prominent larval characters and visible morphological features, S. Canarium larvae can be assigned to 4 different development stages, i.e. stages I, II, III, and IV, which are described in this paper. The larvae reached metamorphic competence at 17-23 d post-hatching, and only metamorphosed when settlement cues (sediments from its natural habitat and 15 mM KCI) were introduced. They showed a short period of metamorphic competence, and no spontaneous metamorphosis was observed. Morphological changes and larval behaviors at the onset and during metamorphosis are also described. http://zoolstud.sinica.edu.tw/Journals/48.1/1.pdf
Jean-michel Harmand - One of the best experts on this subject based on the ideXlab platform.
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Cocoa agroforest multifunctionality and soil fertility explained by shade tree litter traits
Journal of Applied Ecology, 2020Co-Authors: Marie Sauvadet, Stéphane Saj, Grégoire T. Freschet, Jean-daniel Essobo, Seguy Enock, Thierry Becquer, Philippe Tixier, Jean-michel HarmandAbstract:Manipulating plant functional diversity to improve agroecosystem multifunctionality is a central challenge of agricultural systems world-wide. In cocoa agroforestry systems (cAFS), shade trees are used to supply many services to farmers, yet their impact on soil functioning and cocoa yields is likely to vary substantially among tree species. Here we compared the impact of five shade tree species (Canarium schweinfurthii (Canarium), Dacryodes edulis (Safou), Milicia excelsa (Iroko), Ceiba pentandra (Kapok tree), Albizia adianthifolia (Albizia)) and unshaded conditions on the functioning of poor sandy savanna soils within eight cocoa farms in Central Cameroon. We assessed the effects of plant functional traits, leaf litterfall and fine root biomass on a range of soil functions and on cocoa yield. Shade trees generally improved soil pH, NH4+, NO3- and Olsen P content, biomass production of bioassays and soil total C and N content, while leaving cocoa yields unchanged. However, these effects varied largely among species. Improvements of soil functions were low under the two fruit trees (Canarium and Dacryodes), medium under the legume tree Albizia and high under the two timber trees (Milicia and Ceiba). Low litter recalcitrance was most strongly associated with increases in soil fertility indicators such as N and P availability, whereas soil C and N content increased with litter Ca restitution. Synthesis and applications. We demonstrate that cocoa agroforest multifunctionality is substantially influenced by the functional traits of shade tree species. Shade tree species with the most dissimilar traits to cocoa (cocoa showing the lowest leaf litter quality) showed the largest improvement of soil functions. Therefore, selection of shade trees based on their functional traits appears as a promising practice to adequately manage soil functioning. In order to fully assess the beneficial role of shade trees in these agroecosystems. Future research will need to extend this approach to other below-ground traits and other aspects of multifunctionality such as long-term cocoa health and yield.
Aziz Arshad - One of the best experts on this subject based on the ideXlab platform.
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effects of Canarium fruit Canarium odontophyllum oil as a dietary lipid source for juvenile mahseer tor tambroides performance
Aquaculture Reports, 2017Co-Authors: Mahkameh Lashkarizadeh Bami, Aziz Arshad, Mohd Salleh Kamarudin, C R Saad, Mahdi EbrahimiAbstract:Canarium is among the riverine fruits that are commonly found in the natural diet of Malaysian mahseer, Tor tambroides. The fruit contains a high percentage of lipids. This study was conducted to investigate the effects of Canarium crude oil on the growth performance, body composition and fatty acid profile of juvenile T. tambroides. Five isonitrogenous (40% crude protein) diets containing varying Canarium oil levels (0, 1.25, 2.5, 3.75 and 5%) were prepared. Crude palm oil (CPO) was used as the control. The juveniles (2.08 ± 0.10 g) were given the test diets for 12 weeks in triplicate groups. Diets containing Canarium oil were found to be less accepted by the fish which led to a significantly lower (P 0.05) on survival and lean portion of juvenile T. tambroides. The fish fed Canarium oil-free diet also had better tissue fatty acid profile (especially n-3 and n-6 PUFA) as well as better protein, lipid and energy retention than those fed diets including Canarium oil. From the results, Canarium oil extracted from the whole fruit was not recommended as a dietary lipid source for T. tambroides. Moreover, juveniles fed on 0% Canarium oil (5% CPO) utilized dietary saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) more efficiently for their energy requirement than fish given Canarium oil.
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Spatial and Temporal Variations in Strombus Canarium (Gastropoda: Strombidae) Abundance at Merambong Seagrass Bed, Malaysia (Variasi Reruang dan Temporal bagi Kelimpahan Strombus Canarium (Gastropoda: Strombidae)
2016Co-Authors: Sains Malaysiana, Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Di Hamparan Rumput Laut Merambong, Mazlan Abd GhaffarAbstract:The abundance of marine benthic organisms often exhibits distinct distributional patterns, which is generally governed by many physical and biological factors specific to the habitat. In this study, the spatial and temporal variations in abundance of the dog conch, Strombus Canarium Linnaeus 1758, a commercially important marine gastropod, was investigated. Assessment of conch abundance at Merambong seagrass bed, Malaysia, was conducted using a transect belt method. Sampling stations were randomly selected and environmental parameters associated with the habitat were recorded. The species showed distinct spatial distributional pattern. Conch densities were significantly higher in sheltered areas, mainly in mixed seagrass bed dominated by Halophila spp. and with high sediment organic content. The densities were relatively very low in areas dominated by the tape seagrass, Enhalus acoroides. The species studied also showed distinct temporal variation in abundance. The abundance value was seasonally varied with highest density recorded during the wet monsoon season (p<0.05). The densities were otherwise very low during the dry season, except for a slight peak in July. Since the conch is a very important fishery species within the Johor Straits and regulations on their harvesting is still lacking, this information would be very important for their sustainable management
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Habitat preference and usage of Strombus Canarium Linnaeus, 1758 (Gastropoda: Strombidae) in Malaysian seagrass beds
Italian Journal of Zoology, 2012Co-Authors: Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Yosni Bakar, K. D. Simon, A. G. MazlanAbstract:Abstract Despite their economic importance, the ecology of Strombus Canarium is poorly understood and factors influencing their habitat preferences remain largely unexplained. The species was reported as highly associated with seagrass bed ecosystems, but their distribution and specific preferences within the habitat remain unknown. Determining the mechanisms that regulate conch distribution and abundance is of fundamental importance for management of the species. In this study habitat preference and usage of conch in their natural habitat were investigated. The population was patchily distributed and present in local colonies that comprised of mixed age groups. There was high spatial variation in conch abundance, where multivariate analysis (PCA) showed high preferences for microhabitat with mixed seagrasses dominated by Halophila spp. Other important habitat characteristics preferred were high sediment organic content (% LOI), high sediment sorting (φ), and low mean sediment particulate size. Areas with...
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metamorphosis induction of the dog conch strombus Canarium gastropoda strombidae using cues associated with conch nursery habitat
Journal of Applied Sciences, 2010Co-Authors: Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Wan Mohd. Lotfi Wan Muda, Mazlan Abd GhaffarAbstract:Strombus Canarium is a commercially important gastropod that has great potential for advancement into aquaculture. In this study, the metamorphosis response of Strombus Canarium larvae to various metamorphosis cues associated with conch nursery habitat and to KCl and GABA, were tested. Bioassays were run as static, no choice experiment and adopting a continuous exposure approach. Strombus Canarium larvae showed strong metamorphosis responses when sediment (i.e., conch nursery habitat sediment/SD-NU) and detrital substrata (i.e., Thalassia detritus leachate/T-LC) from their nursery habitat were used (p<0.05). There was no metamorphosis in treatments using sterilized conch nursery habitat sediment (SD-ST) and sediment taken from outside conch nursery habitat (SD-OT). Experiments using fresh macrophyte blades of Enhalus acoroides (EA), Thalassia hemprichii (TH), Halophila ovalis (HA) and Ulva (UL) and adult conditioned seawater (SD-SW) also showed negative respond. Conch larvae demonstrate active habitat selection during metamorphosis and no spontaneous metamorphosis was observed. Settlement in S. Canarium is associative in nature where epibionts associated with conch nursery habitat could be the cue for the metamorphosis. However, the specific epibionts/inducers and mechanisms underlining the process were not studied and therefore are subjected to more detailed investigation. The use of KCl was comparable with treatments using natural inducers (SD-NU and T-LC), thus was suggested for application in hatchery spat production of the species.
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age growth mortality and population structure of strombus Canarium gastropoda strombidae variations in male and female sub populations
Journal of Applied Sciences, 2009Co-Authors: Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Mazlan Abd GhaffarAbstract:The age, growth, mortality and population structure of Strombus Canarium Linnaeus, 1758 were examined in the Johor Straits, Malaysia from January to December 2005. A total of 2088 conchs were sampled where females were more abundant than males with monthly sex ratio of 1.72±0.17 (N = 12). The estimated growth parameter showed higher asymptotic length (L∞) and growth coefficient (K) in females (L∞ = 70.20 mm, K = 1.50 year-1) compared with the males (L∞ = 69.30 mm, K = 1.20 year-1). This resulted in better overall growth performance of females (φ’ = 3.81) compared with the males (φ’ = 3.48). The growth pattern of females and males showed positive allometric nature of growth (b>3, p<0.05), with estimated maximum life span of 2.0 and 2.5 year, respectively. The recruitment pattern was continuous, displaying only a single major peak event per year. The estimated natural mortality rate (M) was 0.95 year-1 in females and 0.86 year-1 in males, while the total mortality rate (Z) was 2.56 and 2.72 year-1, respectively. The fishing mortality rate (F) was 1.61 year-1 in females and 1.86 year-1 in males, which were higher than the natural mortality rates, thus indicating an unbalanced position of the stock. In addition, the exploitation rate (E) was higher than the maximum allowable limit of exploitation (EMSY), which was a further indication of overexploitation. For sustainable utilization of the resource, serious efforts should immediately be taken in reducing the exploitation rates of S. Canarium in the study area.
Zaidi Che Cob - One of the best experts on this subject based on the ideXlab platform.
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ontogenetic changes in feeding and food preferences of the dog conch laevistrombus Canarium linnaeus 1758 mollusca gastropoda from merambong shoal malaysia
Chinese Journal of Oceanology and Limnology, 2017Co-Authors: Wan Nurul Wan Hassan Husna, Abd Ghaffar Mazlan, Zaidi Che CobAbstract:Laevistrombus Canarium is one of the marine gastropod mollusks that have high commercial value, particularly in the aquaculture sector in Malaysia. This study was conducted to determine the feeding and food items of L. Canarium at different ontogenetic stages (juveniles, sub-adults and adults) from Merambong shoals, Malaysia. Field observations on feeding activity were conducted, followed by detailed laboratory analysis on the stomach content. Five-minutes observations on randomly selected individuals were conducted at the field sampling site and their feeding activities were recorded with reference to age stage. Various shell sizes from each ontogenetic stage were randomly collected and quickly anaesthetized with ice and preserved in 10% formalin before being transported to the laboratory for stomach content analyses. Field observations showed that L. Canarium mainly grazed on epiphytes occurring on seagrass (46.67%), followed by sediment surface (40%) and epiphytes occurring on macroalgae (13.33%). Stomach content analyses showed a significant difference (P 0.05) was detected between the three main food items (diatoms, sand particles and detritus) among the ontogenetic stages. Therefore, feeding activity revealed the role of the dog conch in the marine food network. While, classification of the types of food consumed by L. Canarium through stomach content analysis determines the particular position of the gastropod in the food chain. Further studies are needed to provide a better insight between trophic relationships of L. Canarium with marine ecosystem.
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Spatial and Temporal Variations in Strombus Canarium (Gastropoda: Strombidae) Abundance at Merambong Seagrass Bed, Malaysia (Variasi Reruang dan Temporal bagi Kelimpahan Strombus Canarium (Gastropoda: Strombidae)
2016Co-Authors: Sains Malaysiana, Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Di Hamparan Rumput Laut Merambong, Mazlan Abd GhaffarAbstract:The abundance of marine benthic organisms often exhibits distinct distributional patterns, which is generally governed by many physical and biological factors specific to the habitat. In this study, the spatial and temporal variations in abundance of the dog conch, Strombus Canarium Linnaeus 1758, a commercially important marine gastropod, was investigated. Assessment of conch abundance at Merambong seagrass bed, Malaysia, was conducted using a transect belt method. Sampling stations were randomly selected and environmental parameters associated with the habitat were recorded. The species showed distinct spatial distributional pattern. Conch densities were significantly higher in sheltered areas, mainly in mixed seagrass bed dominated by Halophila spp. and with high sediment organic content. The densities were relatively very low in areas dominated by the tape seagrass, Enhalus acoroides. The species studied also showed distinct temporal variation in abundance. The abundance value was seasonally varied with highest density recorded during the wet monsoon season (p<0.05). The densities were otherwise very low during the dry season, except for a slight peak in July. Since the conch is a very important fishery species within the Johor Straits and regulations on their harvesting is still lacking, this information would be very important for their sustainable management
-
Habitat preference and usage of Strombus Canarium Linnaeus, 1758 (Gastropoda: Strombidae) in Malaysian seagrass beds
Italian Journal of Zoology, 2012Co-Authors: Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Yosni Bakar, K. D. Simon, A. G. MazlanAbstract:Abstract Despite their economic importance, the ecology of Strombus Canarium is poorly understood and factors influencing their habitat preferences remain largely unexplained. The species was reported as highly associated with seagrass bed ecosystems, but their distribution and specific preferences within the habitat remain unknown. Determining the mechanisms that regulate conch distribution and abundance is of fundamental importance for management of the species. In this study habitat preference and usage of conch in their natural habitat were investigated. The population was patchily distributed and present in local colonies that comprised of mixed age groups. There was high spatial variation in conch abundance, where multivariate analysis (PCA) showed high preferences for microhabitat with mixed seagrasses dominated by Halophila spp. Other important habitat characteristics preferred were high sediment organic content (% LOI), high sediment sorting (φ), and low mean sediment particulate size. Areas with...
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metamorphosis induction of the dog conch strombus Canarium gastropoda strombidae using cues associated with conch nursery habitat
Journal of Applied Sciences, 2010Co-Authors: Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Wan Mohd. Lotfi Wan Muda, Mazlan Abd GhaffarAbstract:Strombus Canarium is a commercially important gastropod that has great potential for advancement into aquaculture. In this study, the metamorphosis response of Strombus Canarium larvae to various metamorphosis cues associated with conch nursery habitat and to KCl and GABA, were tested. Bioassays were run as static, no choice experiment and adopting a continuous exposure approach. Strombus Canarium larvae showed strong metamorphosis responses when sediment (i.e., conch nursery habitat sediment/SD-NU) and detrital substrata (i.e., Thalassia detritus leachate/T-LC) from their nursery habitat were used (p<0.05). There was no metamorphosis in treatments using sterilized conch nursery habitat sediment (SD-ST) and sediment taken from outside conch nursery habitat (SD-OT). Experiments using fresh macrophyte blades of Enhalus acoroides (EA), Thalassia hemprichii (TH), Halophila ovalis (HA) and Ulva (UL) and adult conditioned seawater (SD-SW) also showed negative respond. Conch larvae demonstrate active habitat selection during metamorphosis and no spontaneous metamorphosis was observed. Settlement in S. Canarium is associative in nature where epibionts associated with conch nursery habitat could be the cue for the metamorphosis. However, the specific epibionts/inducers and mechanisms underlining the process were not studied and therefore are subjected to more detailed investigation. The use of KCl was comparable with treatments using natural inducers (SD-NU and T-LC), thus was suggested for application in hatchery spat production of the species.
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age growth mortality and population structure of strombus Canarium gastropoda strombidae variations in male and female sub populations
Journal of Applied Sciences, 2009Co-Authors: Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Mazlan Abd GhaffarAbstract:The age, growth, mortality and population structure of Strombus Canarium Linnaeus, 1758 were examined in the Johor Straits, Malaysia from January to December 2005. A total of 2088 conchs were sampled where females were more abundant than males with monthly sex ratio of 1.72±0.17 (N = 12). The estimated growth parameter showed higher asymptotic length (L∞) and growth coefficient (K) in females (L∞ = 70.20 mm, K = 1.50 year-1) compared with the males (L∞ = 69.30 mm, K = 1.20 year-1). This resulted in better overall growth performance of females (φ’ = 3.81) compared with the males (φ’ = 3.48). The growth pattern of females and males showed positive allometric nature of growth (b>3, p<0.05), with estimated maximum life span of 2.0 and 2.5 year, respectively. The recruitment pattern was continuous, displaying only a single major peak event per year. The estimated natural mortality rate (M) was 0.95 year-1 in females and 0.86 year-1 in males, while the total mortality rate (Z) was 2.56 and 2.72 year-1, respectively. The fishing mortality rate (F) was 1.61 year-1 in females and 1.86 year-1 in males, which were higher than the natural mortality rates, thus indicating an unbalanced position of the stock. In addition, the exploitation rate (E) was higher than the maximum allowable limit of exploitation (EMSY), which was a further indication of overexploitation. For sustainable utilization of the resource, serious efforts should immediately be taken in reducing the exploitation rates of S. Canarium in the study area.
Marie Sauvadet - One of the best experts on this subject based on the ideXlab platform.
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Cocoa agroforest multifunctionality and soil fertility explained by shade tree litter traits
Journal of Applied Ecology, 2020Co-Authors: Marie Sauvadet, Stéphane Saj, Grégoire T. Freschet, Jean-daniel Essobo, Seguy Enock, Thierry Becquer, Philippe Tixier, Jean-michel HarmandAbstract:Manipulating plant functional diversity to improve agroecosystem multifunctionality is a central challenge of agricultural systems world-wide. In cocoa agroforestry systems (cAFS), shade trees are used to supply many services to farmers, yet their impact on soil functioning and cocoa yields is likely to vary substantially among tree species. Here we compared the impact of five shade tree species (Canarium schweinfurthii (Canarium), Dacryodes edulis (Safou), Milicia excelsa (Iroko), Ceiba pentandra (Kapok tree), Albizia adianthifolia (Albizia)) and unshaded conditions on the functioning of poor sandy savanna soils within eight cocoa farms in Central Cameroon. We assessed the effects of plant functional traits, leaf litterfall and fine root biomass on a range of soil functions and on cocoa yield. Shade trees generally improved soil pH, NH4+, NO3- and Olsen P content, biomass production of bioassays and soil total C and N content, while leaving cocoa yields unchanged. However, these effects varied largely among species. Improvements of soil functions were low under the two fruit trees (Canarium and Dacryodes), medium under the legume tree Albizia and high under the two timber trees (Milicia and Ceiba). Low litter recalcitrance was most strongly associated with increases in soil fertility indicators such as N and P availability, whereas soil C and N content increased with litter Ca restitution. Synthesis and applications. We demonstrate that cocoa agroforest multifunctionality is substantially influenced by the functional traits of shade tree species. Shade tree species with the most dissimilar traits to cocoa (cocoa showing the lowest leaf litter quality) showed the largest improvement of soil functions. Therefore, selection of shade trees based on their functional traits appears as a promising practice to adequately manage soil functioning. In order to fully assess the beneficial role of shade trees in these agroecosystems. Future research will need to extend this approach to other below-ground traits and other aspects of multifunctionality such as long-term cocoa health and yield.