Patterns of throughfall deposition along a transect in forest edges of silver birch and Corsican pine

2008 ◽  
Vol 38 (3) ◽  
pp. 449-461 ◽  
Author(s):  
K. Wuyts ◽  
A. De Schrijver ◽  
J. Staelens ◽  
M. Gielis ◽  
G. Geudens ◽  
...  

In two adjacent forest stands in Flanders, one dominated by Corsican pine ( Pinus nigra subsp. laricio Maire) and another dominated by silver birch ( Betula pendula Roth), throughfall deposition was monitored along a transect perpendicular to the forest edge exposed to the prevailing wind direction. Throughfall deposition of Na+, K+, Ca2+, Mg2+, NH4+, NO3–, Cl–, and SO42– was examined on forest edge patterns expressed in the depth of influence of the edge effect (forest edge distance) and the level of enhancement at the edge (forest edge enhancement). In addition, an integrated forest edge enhancement factor was computed that incorporates these two parameters. Our results show that the edge effects on throughfall deposition of Na+, Cl–, the sum of so-called base cations, the sum of potentially acidifying ions, and the sum of inorganic nitrogen (NH4+ + NO3–) are more pronounced in the pine stand. The edge zone of the pine stand receives as a result of the edge effect 9.4 times more extra potentially acidifying ions and 12.7 times more extra inorganic nitrogen than the birch stand. We conclude that an appropriate design or conversion of the edge structure, from high-density Corsican pine plantations into lower density deciduous forests, can reduce the input of acidifying and eutrophying pollutants in the forest edge.

Author(s):  
Siyi Tan ◽  
Dong Qing ◽  
Xiangyin Ni ◽  
kai Yue ◽  
Shu Liao ◽  
...  

Calculations of base cation inputs of loads in forest edge canopies are rare, although forest edge canopies play a paradoxical role in the effective capture of atmospheric deposition. Throughfall deposition and canopy exchange of base cations were studied with a continuous throughfall investigation under a natural forest edge and a closed canopy in a subalpine forest over a period of 2 years. Compared with precipitation, the concentration of base cations in the throughfall of both canopies was enriched as expected, but the enrichment level in the forest edge was less than that in the closed canopy. Moreover, the throughfall deposition of base cation fluxes in the closed canopy (35.19 kg ha-1 y-1) was slightly higher than that in the forest edge canopy (33.50 kg ha-1 y-1). Seasonally, the base cation input in the rainy season was 2.32–2.70 times higher than that in the snowy season in throughfall in forest edge canopy and the closed canopy. Furthermore, the canopy budget model suggested that the direction and magnitude of canopy exchange and dry deposition controlled the net throughfall fluxes (NTF) of base cations, and obvious differences could be observed between the canopy and seasonal scales. Compared with other elements, K and Mg leached from the main canopy exchange process, while Ca was absorbed by both canopy types in the annual NTF. These results highlight the spatial variability of base cation chemical characteristics, enhance cognitive the deposition of nutrients and regulatory factors in different forest landscapes, preferably guide the formulation forest ecological management strategies.


2020 ◽  
Vol 10 (15) ◽  
pp. 5286
Author(s):  
Xiaolong Ke ◽  
Lei Qiu ◽  
Chunjin Wang ◽  
Zhenzhong Wang

The material removal depth in the pre-polishing stage of the precision optics is usually tens of microns to remove the subsurface damage and grinding marks left by the previous grinding process. This processing of the upstand edge takes a large part of the time at this stage. The purpose of this paper is to develop a method that can reduce the edge effect and largely shorten the processing time of the pre-polishing stage adopting the semirigid (SR) bonnet. The generation of the edge effect is presented based on the finite element analysis of the contact pressure at the edge zone firstly. Then, some experimentations on the edge effect are conducted, and the results proved that the SR bonnet tool can overhang the workpiece edge in the pre-polishing stage to reduce the width and height of the upstand edge to largely shorten the subsequent processing time of it. In addition, there exists a perfect overhang ratio, which generates the upstand edge with the smallest width and height, with no damage to the bonnet tool in the meantime. In addition, one combination of the pre-polishing parameters is concluded according to this method, which can be safely adopted in practical process.


2016 ◽  
Vol 23 (3) ◽  
pp. 340-349 ◽  
Author(s):  
Poliana Gabriella Araújo Mendes ◽  
Maria Amanda Menezes Silva ◽  
Tassiane Novacosque Feitosa Guerra ◽  
Ana Carolina Borges Lins-e-Silva ◽  
Airton de Deus Cysneiros Cavalcanti ◽  
...  

ABSTRACT The woody plants in an edge area formed approximately 35 years ago in an Atlantic Forest fragment in northeastern Brazil were examined, and three environments defined: edge, intermediate, and interior. Canopy tree densities and basal areas were found to be similar in all three environments, and also similar to previous published studies in the same region; species richness was greatest at the forest edge. The understory showed greater species richness in the forest interior, but greater diversity and equitability in the intermediate environment. Understory environments close to the forest edge demonstrated larger stem diameters than in the forest interior, although at lesser densities and with smaller total basal areas. Our results indicated the existence of distinct patterns in canopy and understory that most likely reflect differences in the response times of these two vegetation layers, with the understory being more sensitive to alterations in environmental structure.


2017 ◽  
Author(s):  
Ruzhen Wang ◽  
Xue Wang ◽  
Yong Jiang ◽  
Artemi Cerdà ◽  
Jinfei Yin ◽  
...  

Abstract. To understand whether base cations and micronutrients in the plant-soil system change with elevation, we investigated the patterns of base cations and micronutrients in both soils and plant tissues along three elevational gradients and three different climate zones in China. Base cations of Ca, Mg and K and micronutrients of Fe, Mn and Zn were determined in soils, trees and shrubs growing at lower and middle elevations as well as at their upper limits on Balang (subtropical, SW China), Qilian (dry-temperate, NW China) and Changbai (wet-temperate, NE China) mountains. No consistent elevational patterns were found for base cation and micronutrient concentrations in both soils and plant tissues (leaves, roots, shoots and stem sapwood). Rather, soil pH, total soil nitrogen (TN), the soil organic carbon (SOC) to TN ratio (C:N), and total soil inorganic nitrogen (TIN) determined the elevational patterns of soil exchangeable Ca and Mg. Furthermore, multiple regression models showed that soil pH and C:N were pivotal factors affecting soil Fe, Mn and Zn availabilities. In return, soil base cation and micronutrient availabilities played fundamental roles in determining the base cation and micronutrient concentrations in plant tissues. Our results highlight the importance of soil physicochemical properties (mainly SOC, C:N and pH) rather than elevation (i.e., canopy cover and environmental factors, especially temperature), in determining base cation and micronutrient availabilities in soils and subsequently their concentrations in plant tissues.


2008 ◽  
Vol 42 (37) ◽  
pp. 8651-8660 ◽  
Author(s):  
Karen Wuyts ◽  
Kris Verheyen ◽  
An De Schrijver ◽  
Wim M. Cornelis ◽  
Donald Gabriels

Web Ecology ◽  
2001 ◽  
Vol 2 (1) ◽  
pp. 7-13 ◽  
Author(s):  
T. Magura ◽  
B. Tóthmérész ◽  
T. Molnár

Abstract. During 1997 and 1998, we have tested the edge-effect for carabids along oak-hornbeam forest-grass transects using pitfall traps in Hungary. Our hypothesis was that the diversity of carabids will be higher in the forest edge than in the forest interior. We also focused on the characteristic species of the habitats along the transects and the relationships between their distribution and the biotic and abiotic factors. Our results proved that there was a significant edge effect on the studied carabid communities: the Shannon diversity increased significantly along the transects from the forest towards the grass. The diversity of the carabids were significantly higher in the forest edge and in the grass than in the forest interior. The carabids of the forest, the forest edge and the grass are separated from each other by principal coordinates analysis and by indicator species analysis (IndVal), suggesting that each of the three habitats has a distinct species assemblages. There were 5 distinctive groups of carabids: 1) habitat generalists, 2) forest generalists, 3) species of the open area, 4) forest edge species, and 5) forest specialists. It was demonstrated by multiple regression analyses, that the relative air moisture, temperature of the ground, the cover of leaf litter, herbs, shrubs and canopy cover, abundance of the carabids’ preys are the most important factors determining the diversity and spatial pattern of carabids along the studied transects.


2005 ◽  
Vol 35 (3) ◽  
pp. 580-592 ◽  
Author(s):  
Lyn K Baldwin ◽  
Gary E Bradfield

The species richness, community composition, and abundance of bryophytes within taxonomic and functional groups were examined in relation to habitat conditions in forest edge and interior habitats of nine old-growth temperate rain-forest patches remaining after logging in the Nimpkish River Valley of Vancouver Island, British Columbia. Bryophytes were sampled at a fine scale using 0.1 m × 0.3 m microplots to examine responses of species abundance on the forest floor, downed logs, and tree bases and at a coarser scale using 10 m × 2 m belt transects to determine changes in patterns of species richness and distribution. Edge habitats, sampled to a depth of 45 m into the forest fragments, were characterized by greater windthrow disturbance. Within the edge zone, increases in the richness of clearing-affiliated functional groups were associated primarily with the location of windthrown trees and tip-up mounds, rather than with distance from the edge per se. Interior habitats had both greater abundance of old-growth-associated functional groups and total bryophyte cover. The extension of the edge zone to at least 45 m into remnant patches carries implications for minimum patch size requirements in the context of variable-retention logging of coastal temperate rain forests.


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