Construction of big dams on rivers develops artificial lakes or water reservoirs which conceive alterations in soil properties of the upstream catchment area. An undulating topography and freckly soil properties cause...Construction of big dams on rivers develops artificial lakes or water reservoirs which conceive alterations in soil properties of the upstream catchment area. An undulating topography and freckly soil properties cause ups and downs in tree diversity, composition and distribution. The study aimed to evaluate the effect of Gobind Sagar reservoir on soil properties relative to the distance from it and assess its effect on tree diversity, evenness and their distribution in tropical and subtropical forests. Based on data analysis it was found that the soil moisture and organic carbon decreased along with increasing distance from the reservoir. It played a significant role in varying tree diversity. The sites distributed within0-2 km showed significantly higher α and β-diversity indices. Tree species richness and diversity indices showed a strong correlation（p ＆lt; 0.05） with soil moisture and organic carbon content. Simpson＇s and Mc Intosh evenness indices showed a strong negative correlation with soil bulk density. Indirect Detrended Correspondence Analysis（DCA） identified soil moisture and soil organic carbon as two major environmental gradients that influenced tree diversity and their distribution in five tropical and four subtropical forests in an upstream catchment of the reservoir. Mixed forests inhabited moist sites andAcacia-Pinus forests showed an inclination to dry areas. Canonical Correspondence Analysis（CCA）revealed that the tree species in tropical forests were mainly affected by driving forces such as soil moisture,organic carbon and bulk density whereas, in subtropical forest tree species were influenced by elevation, soil p H, EC and clay content.展开更多
Temporal adverbial clause is an important language structure and exhibits different features in English and Chinese,which brings about difficulties for Chinese EFL learners.Based on the theory of Dependency Grammar,th...Temporal adverbial clause is an important language structure and exhibits different features in English and Chinese,which brings about difficulties for Chinese EFL learners.Based on the theory of Dependency Grammar,the study attempts to investigate the ordering distribution of temporal adverbial clauses by Chinese EFL learners at the beginning,intermediate and advanced levels.The results show that:1)Chinese EFL learners at different proficiencies tend to precede temporal adverbial clause to main clause.With the increase of proficiency,the postposition of temporal adverbial clauses by learners increases and is approaching to the ordering preference of target language.2)The ordering distribution of subordinators for temporal adverbial clauses by Chinese EFL learners is consistent with native English,showing a tendency of 100%preposition,which ascribes to the high frequency and salience of subordinators in English.3)MDD is one of the significant motivations that cause the preference of prepositional temporal adverbial clauses by Chinese EFL learners.As a kind of natural language,interlanguage has a unique cognitive mechanism which distinguishes from both native and target language.This study provides a more comprehensive theoretical reference for learners at different proficiencies to understand and learn temporal adverbial clauses,as well as data support from empirical research for language teaching.展开更多
基金financial assistance from Department of Science and Technology, Government of India and necessary facilities from the Department of Silviculture and Agroforestry is acknowledged
文摘Construction of big dams on rivers develops artificial lakes or water reservoirs which conceive alterations in soil properties of the upstream catchment area. An undulating topography and freckly soil properties cause ups and downs in tree diversity, composition and distribution. The study aimed to evaluate the effect of Gobind Sagar reservoir on soil properties relative to the distance from it and assess its effect on tree diversity, evenness and their distribution in tropical and subtropical forests. Based on data analysis it was found that the soil moisture and organic carbon decreased along with increasing distance from the reservoir. It played a significant role in varying tree diversity. The sites distributed within0-2 km showed significantly higher α and β-diversity indices. Tree species richness and diversity indices showed a strong correlation（p ＆lt; 0.05） with soil moisture and organic carbon content. Simpson＇s and Mc Intosh evenness indices showed a strong negative correlation with soil bulk density. Indirect Detrended Correspondence Analysis（DCA） identified soil moisture and soil organic carbon as two major environmental gradients that influenced tree diversity and their distribution in five tropical and four subtropical forests in an upstream catchment of the reservoir. Mixed forests inhabited moist sites andAcacia-Pinus forests showed an inclination to dry areas. Canonical Correspondence Analysis（CCA）revealed that the tree species in tropical forests were mainly affected by driving forces such as soil moisture,organic carbon and bulk density whereas, in subtropical forest tree species were influenced by elevation, soil p H, EC and clay content.
基金supported by the National Social Science Foundation of China(No.21BYY186)。
文摘Temporal adverbial clause is an important language structure and exhibits different features in English and Chinese,which brings about difficulties for Chinese EFL learners.Based on the theory of Dependency Grammar,the study attempts to investigate the ordering distribution of temporal adverbial clauses by Chinese EFL learners at the beginning,intermediate and advanced levels.The results show that:1)Chinese EFL learners at different proficiencies tend to precede temporal adverbial clause to main clause.With the increase of proficiency,the postposition of temporal adverbial clauses by learners increases and is approaching to the ordering preference of target language.2)The ordering distribution of subordinators for temporal adverbial clauses by Chinese EFL learners is consistent with native English,showing a tendency of 100%preposition,which ascribes to the high frequency and salience of subordinators in English.3)MDD is one of the significant motivations that cause the preference of prepositional temporal adverbial clauses by Chinese EFL learners.As a kind of natural language,interlanguage has a unique cognitive mechanism which distinguishes from both native and target language.This study provides a more comprehensive theoretical reference for learners at different proficiencies to understand and learn temporal adverbial clauses,as well as data support from empirical research for language teaching.
