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Edgar C Turner - One of the best experts on this subject based on the ideXlab platform.
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effects of replanting and retention of mature oil palm Riparian Buffers on ecosystem functioning in oil palm plantations
Frontiers in Forests and Global Change, 2019Co-Authors: Christopher R Woodham, Sarah H Luke, Eleanor M Slade, Anak Agung Ketut Aryawan, Paul Manning, Jeanpierre Caliman, Mohd Naim, Edgar C TurnerAbstract:Oil palm plantations are a major agricultural land use in Southeast Asia. In the coming decades large areas of mature oil palm will be cleared and replanted. To inform more sustainable long-term production in this globally important crop, it is crucial we understand how replanting impacts ecosystem functions and services. We investigated whether several production-relevant ecosystems functions (dung removal, soil mesofauna feeding activity, herbivory, herbivore predation, and seed predation), and the simultaneous delivery of all functions (ecosystem multifunctionality), vary between recently-replanted oil palm (1-4 yr) and mature oil palm (23-30 yr) areas. Following new in-country and Roundtable on Sustainable Palm Oil (RSPO) guidelines, Riparian Buffers of mature oil palm, in which subsequent natural regrowth is allowed, are being preserved during the replanting cycle in plantations that lack natural forest reserves. We investigated whether or not mature oil palm Riparian Buffers maintain levels of ecosystem functioning beneficial for palm oil production. Only one function (herbivory) differed between mature and replanted areas, with higher levels of herbivory found in recently replanted oil palm. There was no difference in ecosystem multifunctionality between mature and recently-replanted oil palm. Mature oil palm Riparian Buffers were found to be valuable for maintaining lower levels of herbivory than recently-replanted oil palm. However, no other functions, nor ecosystem multifunctionality, differed between the mature oil palm Riparian Buffers and recently-replanted oil palm. The results of this study suggest that replanting has limited impacts on the ecosystem functions we considered. Furthermore, they suggest mature oil palm Riparian Buffers do not have negative impacts on production-relevant ecosystem functions in oil palm landscapes.
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the impacts of habitat disturbance on adult and larval dragonflies odonata in rainforest streams in sabah malaysian borneo
Freshwater Biology, 2017Co-Authors: Sarah H Luke, Edgar C Turner, Rory A Dow, Stephen G Butler, Chey Vun Khen, David C Aldridge, William A FosterAbstract:Summary Dragonfly assemblages (Odonata: comprising damselflies, Zygoptera; and dragonflies, Anisoptera) in Southeast Asian rainforests are extremely diverse but increasingly threatened by habitat disturbance, including logging and conversion of forest to oil palm plantations. Land-use change can affect dragonfly larval stages by altering within-stream environmental conditions, and adults by loss of perches, shade and hunting habitat. However, the extent to which dragonflies are affected by land-use change is not well known, and strategies for conservation are poorly developed. We surveyed dragonfly adults and larvae, forest quality and stream environmental conditions across 16 streams in Sabah, Malaysia. Habitat surrounding the streams included pristine forest, selectively logged forest, oil palm with forested Riparian buffer strips and oil palm without Buffers. Overall abundance and species richness of adult dragonflies stayed constant with habitat disturbance, but larval abundance and richness decreased with higher habitat disturbance, and larvae were largely absent from oil palm streams. There was also a clear shift in community composition of both adult and larval dragonflies. Anisoptera adults were more species rich and abundant, but Zygoptera adults were less species rich in more disturbed sites. The presence of Riparian Buffers in oil palm plantations offered some protection for forest-associated dragonfly species, and streams with wider Riparian Buffers supported adult assemblages more similar to those found in logged forest. However, oil palm streams with Riparian Buffers still contained a depauperate larval assemblage compared to logged forest areas, and dragonfly assemblages in narrow Riparian buffer streams were similar to those found in streams surrounded by continuous oil palm. Our results provide clear evidence of the effect of land-use change on dragonflies. Conservation efforts to conserve forest communities should target the preservation of existing forest areas, but management within oil palm plantation landscapes to preserve Riparian Buffers can still have a marked beneficial effect on dragonfly communities.
Sarah H Luke - One of the best experts on this subject based on the ideXlab platform.
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effects of replanting and retention of mature oil palm Riparian Buffers on ecosystem functioning in oil palm plantations
Frontiers in Forests and Global Change, 2019Co-Authors: Christopher R Woodham, Sarah H Luke, Eleanor M Slade, Anak Agung Ketut Aryawan, Paul Manning, Jeanpierre Caliman, Mohd Naim, Edgar C TurnerAbstract:Oil palm plantations are a major agricultural land use in Southeast Asia. In the coming decades large areas of mature oil palm will be cleared and replanted. To inform more sustainable long-term production in this globally important crop, it is crucial we understand how replanting impacts ecosystem functions and services. We investigated whether several production-relevant ecosystems functions (dung removal, soil mesofauna feeding activity, herbivory, herbivore predation, and seed predation), and the simultaneous delivery of all functions (ecosystem multifunctionality), vary between recently-replanted oil palm (1-4 yr) and mature oil palm (23-30 yr) areas. Following new in-country and Roundtable on Sustainable Palm Oil (RSPO) guidelines, Riparian Buffers of mature oil palm, in which subsequent natural regrowth is allowed, are being preserved during the replanting cycle in plantations that lack natural forest reserves. We investigated whether or not mature oil palm Riparian Buffers maintain levels of ecosystem functioning beneficial for palm oil production. Only one function (herbivory) differed between mature and replanted areas, with higher levels of herbivory found in recently replanted oil palm. There was no difference in ecosystem multifunctionality between mature and recently-replanted oil palm. Mature oil palm Riparian Buffers were found to be valuable for maintaining lower levels of herbivory than recently-replanted oil palm. However, no other functions, nor ecosystem multifunctionality, differed between the mature oil palm Riparian Buffers and recently-replanted oil palm. The results of this study suggest that replanting has limited impacts on the ecosystem functions we considered. Furthermore, they suggest mature oil palm Riparian Buffers do not have negative impacts on production-relevant ecosystem functions in oil palm landscapes.
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Riparian Buffers in tropical agriculture scientific support effectiveness and directions for policy
Journal of Applied Ecology, 2019Co-Authors: Sarah H Luke, Eleanor M Slade, Claudia L Gray, Kogila Vani Annammala, Julia Drewer, Joseph Williamson, Agnes L Agama, Miklin AtiongAbstract:There is a weak evidence base supporting the effective management of Riparian ecosystems within tropical agriculture. Policies to protect Riparian Buffers—strips of non-cultivated land alongside waterways—are vague and vary greatly between countries. From a rapid evidence appraisal, we find that Riparian Buffers are beneficial to hydrology, water quality, biodiversity and some ecosystem functions in tropical landscapes. However, effects on connectivity, carbon storage and emissions reduction remain understudied. Riparian functions are mediated by buffer width and habitat quality, but explicit threshold recommendations are rare. Policy implications. A one-size fits all width criterion, commonly applied, will be insufficient to provide all Riparian functions in all circumstances. Context-specific guidelines for allocating, restoring and managing Riparian Buffers are necessary to minimise continued degradation of biodiversity and ecosystem functioning in tropical agriculture.
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the impacts of habitat disturbance on adult and larval dragonflies odonata in rainforest streams in sabah malaysian borneo
Freshwater Biology, 2017Co-Authors: Sarah H Luke, Edgar C Turner, Rory A Dow, Stephen G Butler, Chey Vun Khen, David C Aldridge, William A FosterAbstract:Summary Dragonfly assemblages (Odonata: comprising damselflies, Zygoptera; and dragonflies, Anisoptera) in Southeast Asian rainforests are extremely diverse but increasingly threatened by habitat disturbance, including logging and conversion of forest to oil palm plantations. Land-use change can affect dragonfly larval stages by altering within-stream environmental conditions, and adults by loss of perches, shade and hunting habitat. However, the extent to which dragonflies are affected by land-use change is not well known, and strategies for conservation are poorly developed. We surveyed dragonfly adults and larvae, forest quality and stream environmental conditions across 16 streams in Sabah, Malaysia. Habitat surrounding the streams included pristine forest, selectively logged forest, oil palm with forested Riparian buffer strips and oil palm without Buffers. Overall abundance and species richness of adult dragonflies stayed constant with habitat disturbance, but larval abundance and richness decreased with higher habitat disturbance, and larvae were largely absent from oil palm streams. There was also a clear shift in community composition of both adult and larval dragonflies. Anisoptera adults were more species rich and abundant, but Zygoptera adults were less species rich in more disturbed sites. The presence of Riparian Buffers in oil palm plantations offered some protection for forest-associated dragonfly species, and streams with wider Riparian Buffers supported adult assemblages more similar to those found in logged forest. However, oil palm streams with Riparian Buffers still contained a depauperate larval assemblage compared to logged forest areas, and dragonfly assemblages in narrow Riparian buffer streams were similar to those found in streams surrounded by continuous oil palm. Our results provide clear evidence of the effect of land-use change on dragonflies. Conservation efforts to conserve forest communities should target the preservation of existing forest areas, but management within oil palm plantation landscapes to preserve Riparian Buffers can still have a marked beneficial effect on dragonfly communities.
Thomas M. Isenhart - One of the best experts on this subject based on the ideXlab platform.
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long term nitrate removal in three Riparian Buffers 21 years of data from the bear creek watershed in central iowa usa
Science of The Total Environment, 2020Co-Authors: Tyler A. Groh, Thomas M. Isenhart, Richard C SchultzAbstract:Abstract Riparian Buffers are a conservation practice that increases vegetation diversity on the agricultural landscape while providing environmental benefits. This study specifically focused on the ability of Riparian Buffers to remove nitrate from shallow groundwater. There are many studies that assessed nitrate removal within Buffers, but not many have a long-term, continuous data set that can analyze for variation in nitrate removal rates over time. Here we report on 21 years of nitrate well data, from 1996 through 2017, for three Buffers in the Bear Creek watershed in central Iowa. These Buffers are named using abbreviations to help keep landowners anonymous (e.g. RN, RS, and ST). Studied Buffers RS and ST showed greater nitrate reduction (or removal) after 10 and 6 years of its establishment, respectively. Buffer RN did not experience a significant nitrate removal increase with time, but instead had higher nitrate removal rates when compared to Buffers RS and ST of 10.3 g NO3−-N m−1 day−1 from the start of this study. From this data, we suggest that past land management played a major role in the responses observed. RN had previously been established in cool-season grasses for grazing before being converted to a buffer, while RS and ST had been managed in a corn and soybean rotation. RN was thought to have higher denitrification immediately with increased labile soil carbon input and enhanced soil aggregation due to the grassland perennials, while buffer vegetation establishment increased soil carbon inputs and soil aggregation over time for RS and ST. These nitrate removal trends would not have been observed without access to long-term, continuous data. This study highlighted the importance of long-term data sets and the need to assess conservation practices over time to determine their longevity and efficiency with time.
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denitrification potential in three saturated Riparian Buffers
Agriculture Ecosystems & Environment, 2019Co-Authors: Tyler A. Groh, Morgan P. Davis, Thomas M. Isenhart, Dan B. Jaynes, Timothy B. ParkinAbstract:Abstract Denitrification is an anaerobic process that converts nitrate to predominantly either nitrous oxide or dinitrogen gas while using nitrate as a terminal electron acceptor. The requirements for denitrification include available nitrate and organic carbon, an anaerobic environment, and the appropriate microbial communities. The edge-of-field nitrate removal practice of saturated Riparian Buffers (SRBs) looks to maximize soil denitrification by saturating carbon-rich alluvial soils with nitrate-rich tile water. Our initial in situ denitrification study showed the possibility of a carbon limitation for BC-2, the youngest of our study’s SRBs. The current study looked to test this hypothesis using a denitrification potential experimental design by adding nitrate and carbon both individually and combined to portions of soil cores. BC-2 did seem to have a carbon limitation from 20 to 100 cm when assessing the nitrate and carbon separate additions against both the control and the combined nitrate and carbon maximum denitrification potential rate. Temperature also seemed to affect each SRB’s maximum denitrification potential, but to varying degrees. The highest subsurface maximum denitrification potential rate, achieved by adding both nitrate and carbon, at each temperature was achieved by BC-1, the oldest SRB with the highest in situ denitrification rates. Conversely, BC-2, the youngest SRB, had the lowest rate. Thus indicating a potential Riparian age effect on denitrification beyond elevated increased labile carbon additions, hypothesized to be an increased soil aggregation effect on denitrification communities.
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In Situ Denitrification in Saturated Riparian Buffers.
Journal of Environmental Quality, 2019Co-Authors: Tyler A. Groh, Morgan P. Davis, Thomas M. Isenhart, Dan B. Jaynes, Timothy B. ParkinAbstract:: Excess NO leaching from the agricultural Midwest via tile drainage water has contributed to both local drinking water and national Gulf of Mexico benthic hypoxia concerns. Both in-field and edge-of-field practices have been designed to help mitigate NO flux to surface waters. Edge-of-field practices focus on maximizing microbial denitrification, the conversion of NO to N gas. This study assessed denitrification rates from two saturated Riparian Buffers (SRBs) for 2 yr and a third SRB for 1 yr, for a total of five sample years. These SRBs were created by diverting NO-rich tile drainage water into Riparian Buffers soils. The SRBs in this study removed between 27 and 96% of the total diverted NO load. Measured cumulative average denitrification rate for each SRB sample year accounted for between 3.7 and 77.3% of the total NO removed. Both the cumulative maximum and 90% confidence interval denitrification rates accounted for all of the NO removed by the SRBs in three of the five sample years, indicating that denitrification can be a dominant NO removal mechanism in this edge-of-field practice. When adding the top 20 cm of each core to the cumulative denitrification rates for each SRB, denitrification accounted for between 33 and over 100% of the total NO removed. Buffer age (time since establishment) was speculated to enhance denitrification rates, and there was a trend of the soil closer to the surface making up the majority of the total denitrification rate. Finally, both NO and C could limit denitrification in these SRBs.
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nitrous oxide emissions from saturated Riparian Buffers are we trading a water quality problem for an air quality problem
Journal of Environmental Quality, 2019Co-Authors: Morgan P. Davis, Timothy B. Parkin, Tyler A. Groh, Dan B. Jaynes, Thomas M. IsenhartAbstract:Reestablishing perennial vegetation along Riparian areas in agroecosystems reduces nutrient and sediment losses from agricultural lands. However, subsurface (tile) drains bypass traditional Buffers routing the majority of shallow groundwater straight to surface waters, limiting their nutrient removal capabilities. Saturated Riparian Buffers (SRBs) reconnect subsurface drainage water with the soil profile to remove NO in tile water through microbial denitrification. One concern of enhancing denitrification on agricultural landscapes is the potential increase in NO emissions from incomplete denitrification. Our objective was to compare NO emissions from SRBs to traditional Buffers and bordering crop fields at two sites, Bear Creek Site 1 and Iowa Site 1, in Central Iowa. We measured NO emissions directly from the soil surface and dissolved in shallow groundwater and estimated indirect emissions from downstream denitrification from 2015 through 2017. Nitrous oxide emissions from soil surfaces were greatest from fertilized corn ( L.). Saturated Riparian Buffers were only significantly greater ( < 0.05) than traditional Buffers in one out of six site-years. Dissolved NO in shallow groundwater seeping from SRBs was not significantly greater ( < 0.05) than dissolved NO from the tile outlet among site years. Indirect NO emissions from rivers and estuaries were significantly reduced from NO removal in both SRBs. Overall, total NO emissions from SRBs were similar to those from traditional Buffers and less than those from fertilized corn-soybean [ (L.) Merr.] agriculture. Replacing cultivated land in Riparian areas with a SRB has shown potential to subsequently remove NO from surface waters and reduce NO emissions from agricultural landscapes.
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performance of saturated Riparian Buffers in iowa usa
Journal of Environmental Quality, 2019Co-Authors: D B Jaynes, Thomas M. IsenhartAbstract:Nitrate from artificial drainage pipes (tiles) underlying agricultural fields is a major source of reactive N, especially NO, in surface waters. A novel approach for reducing NO loss is to intercept a field tile where it crosses a Riparian buffer and divert a fraction of the flow as shallow groundwater within the buffer. This practice is called a saturated Riparian buffer (SRB), and although it is promising, little data on the performance of the practice is available. This research investigated the effectiveness of SRBs in removing NO at six sites installed across Iowa, resulting in a total of 17 site-years. Water flow and NO in the tile outlets, diverted into the Buffers, and NO concentration changes within the Buffers were monitored throughout the year at each site. Results showed that all the SRBs were effective in removing NO from the tile outlet, with the average annual NO load removal ranging from 13 to 179 kg N for drainage areas ranging from 3.4 to 40.5 ha. This is NO that would have otherwise discharged directly into the adjoining streams. The annual removal effectiveness, which is the total NO removed in the SRB divided by the total NO draining from the field, ranged from 8 to 84%. This corresponds to an average removal rate of 0.040 g N m d with a range of 0.004 to 0.164 g N m d. Assuming a 40-yr life expectancy for the structure and a 4% discount rate, we computed a mean equal annual cost for SRBs of US$213.83. Given the average annual removal of 73 kg for all site-years, this cost equates to $2.94 kg N removed, which is very competitive with other field-edge practices such as denitrification bioreactors and constructed wetlands. Thus, SRBs continue to be a promising practice for NO removal in tile-drained landscapes.
Eleanor M Slade - One of the best experts on this subject based on the ideXlab platform.
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effects of replanting and retention of mature oil palm Riparian Buffers on ecosystem functioning in oil palm plantations
Frontiers in Forests and Global Change, 2019Co-Authors: Christopher R Woodham, Sarah H Luke, Eleanor M Slade, Anak Agung Ketut Aryawan, Paul Manning, Jeanpierre Caliman, Mohd Naim, Edgar C TurnerAbstract:Oil palm plantations are a major agricultural land use in Southeast Asia. In the coming decades large areas of mature oil palm will be cleared and replanted. To inform more sustainable long-term production in this globally important crop, it is crucial we understand how replanting impacts ecosystem functions and services. We investigated whether several production-relevant ecosystems functions (dung removal, soil mesofauna feeding activity, herbivory, herbivore predation, and seed predation), and the simultaneous delivery of all functions (ecosystem multifunctionality), vary between recently-replanted oil palm (1-4 yr) and mature oil palm (23-30 yr) areas. Following new in-country and Roundtable on Sustainable Palm Oil (RSPO) guidelines, Riparian Buffers of mature oil palm, in which subsequent natural regrowth is allowed, are being preserved during the replanting cycle in plantations that lack natural forest reserves. We investigated whether or not mature oil palm Riparian Buffers maintain levels of ecosystem functioning beneficial for palm oil production. Only one function (herbivory) differed between mature and replanted areas, with higher levels of herbivory found in recently replanted oil palm. There was no difference in ecosystem multifunctionality between mature and recently-replanted oil palm. Mature oil palm Riparian Buffers were found to be valuable for maintaining lower levels of herbivory than recently-replanted oil palm. However, no other functions, nor ecosystem multifunctionality, differed between the mature oil palm Riparian Buffers and recently-replanted oil palm. The results of this study suggest that replanting has limited impacts on the ecosystem functions we considered. Furthermore, they suggest mature oil palm Riparian Buffers do not have negative impacts on production-relevant ecosystem functions in oil palm landscapes.
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Riparian Buffers in tropical agriculture scientific support effectiveness and directions for policy
Journal of Applied Ecology, 2019Co-Authors: Sarah H Luke, Eleanor M Slade, Claudia L Gray, Kogila Vani Annammala, Julia Drewer, Joseph Williamson, Agnes L Agama, Miklin AtiongAbstract:There is a weak evidence base supporting the effective management of Riparian ecosystems within tropical agriculture. Policies to protect Riparian Buffers—strips of non-cultivated land alongside waterways—are vague and vary greatly between countries. From a rapid evidence appraisal, we find that Riparian Buffers are beneficial to hydrology, water quality, biodiversity and some ecosystem functions in tropical landscapes. However, effects on connectivity, carbon storage and emissions reduction remain understudied. Riparian functions are mediated by buffer width and habitat quality, but explicit threshold recommendations are rare. Policy implications. A one-size fits all width criterion, commonly applied, will be insufficient to provide all Riparian functions in all circumstances. Context-specific guidelines for allocating, restoring and managing Riparian Buffers are necessary to minimise continued degradation of biodiversity and ecosystem functioning in tropical agriculture.
Vincent H Resh - One of the best experts on this subject based on the ideXlab platform.
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do Riparian Buffers protect stream invertebrate communities in south american atlantic forest agricultural areas
Environmental Management, 2017Co-Authors: Lisa Hunt, Natalia Marrochi, Carlos Bonetto, Matthias Liess, Daniel Forsin Buss, Vieira C Da Silva, Mingchih Chiu, Vincent H ReshAbstract:We investigated the influence and relative importance of insecticides and other agricultural stressors in determining variability in invertebrate communities in small streams in intensive soy-production regions of Brazil and Paraguay. In Paraguay we sampled 17 sites on tributaries of the Pirapo River in the state of Itapua and in Brazil we sampled 18 sites on tributaries of the San Francisco River in the state of Parana. The Riparian buffer zones generally contained native Atlantic forest remnants and/or introduced tree species at various stages of growth. In Brazil the stream buffer width was negatively correlated with sediment insecticide concentrations and buffer width was found to have moderate importance in mitigating effects on some sensitive taxa such as mayflies. However, in both regions insecticides had low relative importance in explaining variability in invertebrate communities, while various habitat parameters were more important. In Brazil, the percent coverage of soft depositional sediment in streams was the most important agriculture-related explanatory variable, and the overall stream-habitat score was the most important variable in Paraguay streams. Paraguay and Brazil both have laws requiring forested Riparian Buffers. The ample forested Riparian buffer zones typical of streams in these regions are likely to have mitigated the effects of pesticides on stream invertebrate communities. This study provides evidence that Riparian buffer regulations in the Atlantic Forest region are protecting stream ecosystems from pesticides and other agricultural stressors. Further studies are needed to determine the minimum buffer widths necessary to achieve optimal protection.
