Strong Convergence Theorems for Nonexpansive Mappings by Viscosity Approximation Methods in Banach Spaces

In this paper, we introduce a modified Ishikawa iterative process for a pair of nonexpansive mappings and obtain a strong convergence theorem in the framework of uniformly Banach spaces. Our results improve and extend the recent ones announced by Kim and Xu [T.H. Kim, H.K. Xu, Strong convergence of modified Mann iterations, Nonlinear Anal. 61 (2005) 51-60], Xu [H.K. Xu, Viscosity approximation methods for nonexpansive mappings. J. Math. Anal. Appl. 298 (2004) 279-291] and some others.</p

Moudafi's Viscosity Approximations with Demi-Continuous and Strong Pseudo-Contractions for Non-Expansive Semigroups

We consider viscosity approximation methods with demi-continuous strong pseudo-contractions for a non-expansive semigroup. Strong convergence theorems of the purposed iterative process are established in the framework of Hilbert spaces

Effects ofAgeratina adenophoraInvasion on the Understory Community and Soil Phosphorus Characteristics of Different Forest Types in Southwest China

Understanding the influence of invasive species on community composition and ecosystem properties is necessary to maintain ecosystem functions. However, little is known about how understory plant communities and soil nutrients respond to invasion under different land cover types. Here, we investigated the effects of the invasive species Ageratina adenophora on the species and functional diversity of understory communities and on soil phosphorus (P) status in three forest types: CF, coniferous forest; MF, coniferous and broadleaf mixed forest; and EBF, evergreen broadleaf forest. We found that the species and functional diversity indices of the understory community significantly varied by forest type. Among the invaded plots, the greatest decrease in functional diversity (functional richness, functional divergence, and functional dispersion) and biotic homogenization were found in the CF rather than the MF or EBF. In addition, the invasion by A. adenophora significantly increased the soil NaHCO3-extractable inorganic P and organic P in the MF and EBF, respectively, while obviously decreasing the soil maximum P sorption capacity and maximum buffering capacity in the CF. However, the changes in the species and functional attributes of the understory communities were weakly associated with changes in the soil P status, probably because of the different response times to invasion in different forest types. The implication of these changes for ecosystem structure and function must be separately considered when predicting and managing invasion at a landscape scale

On the Convergence for an Iterative Method for Quasivariational Inclusions

<p/> <p>We introduce an iterative algorithm for finding a common element of the set of solutions of quasivariational inclusion problems and of the set of fixed points of strict pseudocontractions in the framework Hilbert spaces. The results presented in this paper improve and extend the corresponding results announced by many others.</p

On the Convergence for an Iterative Method for Quasivariational Inclusions

We introduce an iterative algorithm for finding a common element of the set of solutions of quasivariational inclusion problems and of the set of fixed points of strict pseudocontractions in the framework Hilbert spaces. The results presented in this paper improve and extend the corresponding results announced by many others

Plant Traits Guide Species Selection in Vegetation Restoration for Soil and Water Conservation

Great efforts have been made to improve the soil and water conservation capacity by restoring plant communities in different climatic and land-use types. However, how to select suitable species from local species pools that not only adapt to different site environments, but also achieve certain soil and water conservation capacities is a great challenge in vegetation restoration for practitioners and scientists. So far, little attention has been paid to plant functional response and effect traits related to environment resource and ecosystem functions. In this study, together with soil properties and ecohydrological functions, we measured the seven plant functional traits for the most common species in different restoration communities in a subtropical mountain ecosystem. Multivariate optimization analyses were performed to identify the functional effect types and functional response types based on specific plant traits. We found that the community-weighted means of traits differed significantly among the four community types, and the plant functional traits were strongly linked with soil physicochemical properties and ecohydrological functions. Based on three optimal effect traits (specific leaf area, leaf size, and specific root length) and two response traits (specific leaf area and leaf nitrogen concentration), seven functional effect types in relation to the soil and water conservation capacity (interception of canopy and stemflow, maximum water-holding capacity of litter, maximum water-holding capacity of soil, soil surface runoff, and soil erosion) and two plant functional response types to soil physicochemical properties were identified. The redundancy analysis showed that the sum of all canonical eigenvalues only accounted for 21.6% of the variation in functional response types, which suggests that community effects on soil and water conservation cannot explain the overall structure of community responses related to soil resources. The eight overlapping species between the plant functional response types and functional effect types were ultimately selected as the key species for vegetation restoration. Based on the above results, we offer an ecological basis for choosing the appropriate species based on functional traits, which may be very helpful for practitioners involved in ecological restoration and management