This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the s...This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the study, namely Mangoum, Makeka and Fossang, representative of the three dominant soil types of the noun plain (Andosols, Acrisols and Ferralsols). Three land uses were selected per site including natural vegetation, agroforest and crop field. Soil was sampled at three depths;0 - 20 cm, 20 - 40 cm, and 40 - 60 cm. Analysis of variance showed that soil type did not significantly influence carbon storage, but rather land uses and soil depth. SOCS decreased significantly with depth in all the sites, with an average stock of 66.3 ± 15.8 tC/ha at 0 - 20 cm, compared to an average stock of 33.3 ± 7.4 tC/ha at 40 - 60 cm. SOCS was significantly highest in the natural formation with 57.2 ± 19.7 tC/ha, and lowest in cultivated fields, at 37.7 ± 10.6 tC/ha. Andosols, with their high content of coarse fragments, stored less organic carbon than Ferralsols and Acrisols.展开更多
Based on more comparable corpora, the present study verified some of the previous findings about the use of adverbial connectors by Chinese learners. Also some new insights have been gained: 1) the overuse of resultiv...Based on more comparable corpora, the present study verified some of the previous findings about the use of adverbial connectors by Chinese learners. Also some new insights have been gained: 1) the overuse of resultive and listing adverbial connectors implies that the learners adopt different ways of argumentation from the native speakers; 2) the use of adverbial connectors is relevant to the learners' proficiency;3) the command of a small variety of adverbial connectors is possibly one of the causes for the overuse of the high frequency ones. Comparisons with learners of other L1 backgrounds indicate that the following two features are common to EFL learners: 1) they tend to rely heavily on the top ten adverbial connectors for linking purposes; 2) the overuse and underuse reflect a general stylistic uncertainty about the use of adverbial connectors by the EFL learners.展开更多
文摘This study was conducted to assess the current stock of soil organic carbon under different agricultural land uses, soil types and soil depths in the Noun plain in western Cameroon. Three sites were selected for the study, namely Mangoum, Makeka and Fossang, representative of the three dominant soil types of the noun plain (Andosols, Acrisols and Ferralsols). Three land uses were selected per site including natural vegetation, agroforest and crop field. Soil was sampled at three depths;0 - 20 cm, 20 - 40 cm, and 40 - 60 cm. Analysis of variance showed that soil type did not significantly influence carbon storage, but rather land uses and soil depth. SOCS decreased significantly with depth in all the sites, with an average stock of 66.3 ± 15.8 tC/ha at 0 - 20 cm, compared to an average stock of 33.3 ± 7.4 tC/ha at 40 - 60 cm. SOCS was significantly highest in the natural formation with 57.2 ± 19.7 tC/ha, and lowest in cultivated fields, at 37.7 ± 10.6 tC/ha. Andosols, with their high content of coarse fragments, stored less organic carbon than Ferralsols and Acrisols.
文摘Based on more comparable corpora, the present study verified some of the previous findings about the use of adverbial connectors by Chinese learners. Also some new insights have been gained: 1) the overuse of resultive and listing adverbial connectors implies that the learners adopt different ways of argumentation from the native speakers; 2) the use of adverbial connectors is relevant to the learners' proficiency;3) the command of a small variety of adverbial connectors is possibly one of the causes for the overuse of the high frequency ones. Comparisons with learners of other L1 backgrounds indicate that the following two features are common to EFL learners: 1) they tend to rely heavily on the top ten adverbial connectors for linking purposes; 2) the overuse and underuse reflect a general stylistic uncertainty about the use of adverbial connectors by the EFL learners.
