Your search found 7 records
1 Jouquet, P.; Bottinelli, N.; Mathieu, J.; Orange, Didier; Podwojewski, Pascal; Henry des Tureaux, Thierry; Toan, Tran Duc. 2007. Impact of land-use change on earthworm diversity and activity: the consequences for soil fertility and soil erosion. In 2nd International Conference on Sustainable Sloping Lands and Watershed Management, LuangPhrabang, Laos, 12-15 December 2006. pp.127-138.
Land use ; Earthworms ; Soil fertility ; Soil properties ; Erosion ; Runoff ; Infiltration ; Cassava ; Farming systems ; Eucalyptus / Vietnam / Dong Cao Watershed
(Location: IWMI HQ Call no: IWMI 631.4 G784 JOU Record No: H040804)
http://www.nafri.org.la/documents/SSLWM/SSLWMpapers/chapter2/ch2_02_jouguet.pdf
https://vlibrary.iwmi.org/pdf/H040804.pdf
https://vlibrary.iwmi.org/pdf/H040804.pdf
Earthworms are considered useful indicators for monitoring different farming practices, landscape structures and transformations because they respond quickly to land-use change. Many articles have been written on the effects of soil macrofauna (termites and earthworms) on soil properties and the functioning of ecosystems. These soil animals are usually considered to have a positive influence on soil organic matter decomposition and nutrient cycling. They increase the concentration of nutrients in their biogenic structures (casts, sheetings, nests, galleries etc.) and promote the growth and diversity of plants. However, there is a lack of data concerning their impact on tropical ecosystems with steep slopes. This study is part of the Management of Soil Erosion Consortium (MSEC) project, which examines the effects of land-use changes on soil erosion on a southeast Asian regional scale. The aim of the study was to evaluate the recovery potential of earthworms and their effects on soil conservation in areas where cassava crops were replaced by four different types of vegetation cover. It was conducted in an experimental watershed in Hoa Binh province, a mountainous area of northern Vietnam. Results showed that landuse change affects earthworm diversity and that this has significant consequences in terms of soil fertility, water infiltration and soil erosion. In plots planted with eucalyptus, large amounts of plant litter and probably higher soil moisture levels favour Pheretima leucocirca activity. These worms produce surface casts, which then became free aggregates, and galleries which are sometimes open at the surface. Casts, galleries and aggregates increase water infiltration and thus reduced water runoff and soil erosion. Cassava, fallow and fodder, however, favour Metaphire californica worms, which do not make casts. A soil crust is formed, which leads to a decrease in water infiltration and increased soil erosion. The data clearly shows that biological parameters such as earthworm diversity and activity must not be neglected in studies of the determinants of soil erosion after land-use change. Upland land-use systems with vegetation that produces lots of ground litter may help encourage beneficial worm species (such as Ph. leucocirca) and thus help reduce soil erosion and accelerate restoration of degraded land.
2 Jouquet, P.; Podwojewski, P.; Bottinelli, N.; Mathieu, J.; Orange, Didier; Tran, D. T.; Valentin, Christian. 2007. Impact du changement d’usage des sols sur la biodiversite: consequences sur l’erosion des sols. Gestion integree des eaux et des sols : ressources, amenagements et risques en milieux ruraux et urbains, Editions AUF et IRD, Hanoi, Actes des Premieres Journees Scientifiques Inter- Reseaux de l’AUF, Hanoi, 6-9 novembre 2007; Paper presented at Conference, Integrated Management of Waters and Soils: Resources, infrastructures and risks in rural and urban areas, Hanoi, Vietnam, 6-9 November 2007. 6p.
Erosion ; Runoff ; Ecosystems ; Biodiversity ; Soil management / Vietnam / Dong Cao experimental watershed
(Location: IWMI HQ Call no: IWMI 631.45 G784 JOU Record No: H040810)
This study deals with the influence of land use change on earthworm diversity on the one hand and the consequences of these modifications on soil erosion on the other hand. This work has been realized in the Northern Vietnam, in the Dong Cao experimental watershed (average slope ~40%). Our work shows that endogeic earthworms are associated to agrosystems with low vegetation cover (or low litter content) while agrosystems with high vegetation cover are characterized by anecic earthworms that create casts on the soil surface. The quantity of soil accumulated on the soil surface by earthworms can be very important (10-20kg m-²). A simulation of water runoff associated to the annual measurement of soil erosion from 1m² plots shows that casts deposited on the soil surface lead to a better infiltration of water but do not increase soil erosion. This study highlights that other biological factors than the vegetation must be considered for a sustainable management of steep slope agro-ecosystems in the Northern Vietnam.
3 Jouquet, P.; Podwojewski, Pascal; Bottinelli, N.; Mathieu, J.; Martinez, M. R.; Orange, Didier; Toan, Tran Duc; Valentin, Christian. 2008. Above-ground earthworm casts affect water runoff and soil erosion in northern Vietnam. Catena, 74(1): 13-21.
(Location: IWMI HQ Call no: IWMI 631.45 G784 PAS Record No: H040814)
4 Choosai, C.; Mathieu, J.; Hanboonsong, Y.; Jouquet, Pascal. 2009. Termite mounds and dykes are biodiversity refuges in paddy fields in north-eastern Thailand. Environmental Conservation, 36(1):71-79. [doi: https://doi.org/10.1017/S0376892909005475]
Paddy fields ; Biodiversity ; Isoptera ; Habitats ; Land management ; Agroecosystems / Thailand / Khon Kaen province / Ban Fang amphur / Baan Daeng village
(Location: IWMI HQ Call no: e-copy only Record No: H042316)
http://journals.cambridge.org/production/action/cjoGetFulltext?fulltextid=5571120
https://vlibrary.iwmi.org/pdf/H042316.pdf
https://vlibrary.iwmi.org/pdf/H042316.pdf
(0.93 MB)
Paddy fields in north-eastern Thailand are heterogeneous agro-ecosystems that can be described as mosaics of paddy rice plots, dykes and termitemounds. The aim of this study was to determine if this heterogeneity influences soil macrofauna biodiversity. While biodiversity did not vary as a result of different rice management practices (direct seeding and transplanting), dykes and mounds were vital to the maintenance of soil macrofauna biodiversity. Diversity and density were higher in termite mounds and field dykes, compared to rice plots, especially during the rainy season. Consequently, termitemounds and dykes can be considered to be biodiversity hotspots that behave as refuges for other soilmacrofauna during the rainy and dry seasons, providing protection against flooding and dryness. The importance of these patches of biological activity in terms of ecosystem functioning and services are discussed.
5 Mathieu, J.; Grimaldi, M.; Jouquet, Pascal; Rouland, C.; Lavelle, P.; Desjardins, T.; Rossi, J. P. 2009. Spatial patterns of grasses influence soil macrofauna biodiversity in Amazonian pastures. Soil Biology and Biochemistry, 41(3):586-593. [doi: https://doi.org/10.1016/j.soilbio.2008.12.020]
Pastures ; Soil organisms ; Soil fauna ; Biodiversity ; Soil temperature ; Statistical methods / South America / Amazon
(Location: IWMI HQ Call no: e-copy only Record No: H042326)
(0.45 MB)
Grasslands are often characterized by small-scale spatial eterogeneity due to the juxtaposition of grass tufts and bare ground. Although the mechanisms generating plant spatial patterns have been widely studied, few studies concentrated on the consequences of these patterns on belowground macrofauna. Our objective was to analyze the impact of grass tuft (Brachiaria bryzantha cv. marandu) spatial distribution on soil macrofauna diversity in Amazonian pastures, at a small scale (less than 9 m2). Soil macrofauna was sampled among B. bryzantha tufts, which showed a variable spatial distribution ranging from dense to loose vegetation cover. The vegetation configuration explained 69% of the variation in total soil macrofauna density and 68% of the variation in total species richness. Soil macrofauna was mainly found in the upper 10 cm of soil and biodiversity decreased with increasing distances to the nearest grass tuft and increased with increasing vegetation cover. The size of the largest grass tuft and the microlandscape connectivity also had a significant effect on biodiversity. The density and species richness of the three principal soil ecological engineers (earthworms, ants and termites) showed the best correlations with vegetation configuration. In addition, soil temperature significantly decreased near the plants, while soil water content was not influenced by the grass tufts. We conclude that soil macrofauna diversity is low in pastures except close to the grass tufts, which can thus be considered as biodiversity hotspots. The spatial arrangement of B. bryzantha tussocks influences soil macrofauna biodiversity by modifying soil properties in their vicinity. The possible mechanisms by which these plants could affect soil macrofauna are discussed.
6 Bottinelli, N.; Henry des Tureaux, Thierry; Hallaire, V.; Mathieu, J.; Benard, Y.; Toan, Tran Duc; Jouquet, Pascal. 2010. Earthworms accelerate soil porosity turnover under watering conditions. Geoderma, 156(1-2):43-47. [doi: https://doi.org/10.1016/j.geoderma.2010.01.006]
(Location: IWMI HQ Call no: e-copy only Record No: H042815)
(0.56 MB)
Endogeic earthworms significantly modify soil aggregation and porosity, which in turn control water flow in soil. This study aimed to determine how the earthworm casting activity influences soil porosity and its dynamics. The main hypothesis was that the deposition of belowground water-stable casts increases soil porosity and its water stability. First we quantified cast production by the endogeic earthworm species Metaphire posthuma under laboratory conditions for 15 days. Secondly, casts and the bulk soil were analysed for structural stability to water and were packed in soil and subjected to wetting under various conditions and energy levels. The shape and size of pores were measured by image analysis. Almost all casts (98%) were produced belowground. M. posthuma produced approximately five times its own weight per day. Casts were depleted in C and were more easily disaggregated by water than the bulk soil. Although casts initially led to larger soil porosity (on average 50%), their structure was unstable. As a consequence, water inputs led to a faster decrease in soil porosity in the presence of casts. Large pores in between casts were rapidly replaced by small elongated and rounded pores. These results suggest that cast lifespan and associated porosity are of primary importance in the regulation of soil porosity turnover and the ecological functions that are under its control. Our findings suggest that in the field, the low stability of casts is likely to lead to a rapid compaction of the soil after rainfall events. However, high levels of cast production may prevent soil porosity from being broken down. Soil structural porosity thus depends on the balance between the production and degradation of casts. Improvements to the soil structure will occur when the former predominates.
7 Jouquet, Pascal; Henry des Tureaux, Thierry; Mathieu, J.; Doan Thu, Thuy; Toan, Tran Duc; Orange, Didier. 2010. Utilization of Near Infrared Reflectance Spectroscopy (NIRS) to quantify the impact of earthworms on soil and carbon erosion in steep slope ecosystem: a study case in northern Vietnam. Catena, 81(2):113-116. [doi: https://doi.org/10.1016/j.catena.2010.01.010]
(Location: IWMI HQ Call no: e-copy only Record No: H042814)
(0.65 MB)
This work focuses on a new approach to quantify the effects of above-ground earthworm's activity on soil erosion in steep slope ecosystems such as in Northern Vietnam. In these areas and in many others in the world, soil erosion becomes a major issue while the factors that determine it are still misunderstood. Earthworm's activity is believed to influence soil erosion rate, but we are still unable to precisely quantify their contribution to soil erosion. In this study, we used Near Infrared Reflectance Spectroscopy (NIRS) to quantify the proportion of soil aggregate in eroded soil coming from earthworm activity. This was done by generating NIRS signatures corresponding to different soil surface aggregates (above-ground soil casts produced by earthworms vs. surrounding topsoil). In order to test the proposed approach, we compared the NIRS-signature of eroded soil sediments to those of earthworms' casts and of the surrounding soils. Our results strongly supported that NIRS spectra might be used as “fingerprints” to identify the origin of soil aggregates. Although earthworms are generally assumed to play a favorable role in promoting soil fertility and ecosystem services, this method shows that cast aggregates constitute about 36 and 77% of sediments in two tropical plantations, Paspalum atratumand Panicum maximum plantations, respectively. In light with these results, we estimated that earthworms led to an annual loss of 3.3 and 15.8 kg of carbon ha-1 yr-1, respectively in P. atratum and P. maximum agroecosystems.
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