scholarly journals Floristic Composition: Dynamic Biodiversity Indicator of Tree Canopy Effect on Dryland and Improved Mediterranean Pastures

Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1128
Author(s):  
João Serrano ◽  
Shakib Shahidian ◽  
Eliana Machado ◽  
Luís L. Paniagua ◽  
Emanuel Carreira ◽  
...  
Keyword(s):  
Indicator Species ◽  
Soil Amendment ◽  
Floristic Composition ◽  
Tree Canopy ◽  
Soil Parameters ◽  
Biodiversity Indicator ◽  
Canopy Effect ◽  
Before And After ◽  
Dynamic Attributes ◽  
Pasture Productivity

Montado is a characteristic ecosystem of the Mediterranean region. The adequate management of this silvo-pastoral ecosystem requires good understanding of the effect of factors such as tree canopy, fertilization and soil amendment on pasture growth. The main objectives of this work were: (1) to evaluate the effect of tree canopy on soil characteristics and pasture productivity and quality; and (2) to test floristic composition assessment as a bio-indicator of soil improvements (amendment and fertilization) in each study area (under and outside tree canopy). Topsoil was characterized at the beginning of the project (October 2015) and at the end of the experiments (spring 2020). Soil parameters obtained by electronic sensors (soil moisture content, soil cone index and surface temperature) were monitored monthly during the 2017/2018 pasture vegetative cycle. Pasture productivity, quality and floristic composition were evaluated every two years (2016, 2018 and 2020) in the spring flowering period. The results of the floristic inventory were submitted to a multilevel pattern analysis (Indicator Species Analysis, ISA). Pasture biodiversity was evaluated based on the calculation of richness indices. This study showed a positive effect of tree canopy on soil fertility and pasture quality (e.g., CP). Pasture productivity, on the other hand, was higher in areas outside tree canopy. The great potential of ISA as a tool for identification of bio-indicator species was also demonstrated. Pasture species were identified as ecological and dynamic attributes characteristic of each study area, before and after soil amendment and fertilization.

scholarly journals The Effect of Soil Reinforcement on the Stress and Strain Field Around Underground Square-Shaped Areas and its Internal Lining Efforts in Urban Areas

2018 ◽  
Vol 4 (11) ◽  
pp. 2756 ◽  
Author(s):  
Alireza Darvishpour ◽  
Asadollah Ranjbar ◽  
Amirmohammad Amiri
Keyword(s):  
Urban Areas ◽  
Underground Structure ◽  
Physical Modelling ◽  
Soil Reinforcement ◽  
Soil Parameters ◽  
Stress And Strain ◽  
Horizontal Distance ◽  
Underground Structures ◽  
Finite Element Software ◽  
Before And After

The passage of underground structures from the bottom of the structures on the ground causes a change in the stresses and strains created in the structure as well as the soil environment surrounding the tunnel due to the existence of an interaction between these two sides. In this way, the existence of the surface structure leads to a change in the strain and stress conditions around the tunnel, and in contrast, the tunnel also leads to a change in the stress and settlement around the structures. Therefore, such a reciprocal behavior is very important. In this research, with the help of Abaqus finite element software, two main possible conditions are considered: the creation of an underground structure in the presence of the superstructure, as well as the reverse state of the concept of constructing a building in the state in which the underground structure already exists. One of the subjects studied in this research is the physical modelling effect of the structure, rather than the effect of its wide load on the ground. Other parameters considered in this research are the number of story, the depth of the tunnel, the width of the tunnel, the thickness of the lining, the effect of changes in the soil parameters in the depth and the horizontal distance of the tunnel center from the building center. The results of this research are validated based on the results obtained by other researchers. According to the results obtained in this research, by the increase of the distance between the tunnel center and structure center and depending on the stiffness of the tunnel lining, significant asymmetric stresses are created in the superstructure. The construction of the structure before and after the tunnel construction can affect the unsymmetrical settlement of the structure The stress and strain created in the lining of the tunnel and the surrounding area are also different due to the amount of mobilized force in the reinforcements.

scholarly journals Floristic dissimilarity and indicator species of Araucaria Forest and ecotones.

FLORESTA ◽  
2015 ◽  
Vol 45 (3) ◽  
pp. 497
Author(s):  
Silvana Manfredi ◽  
Juliano Pereira Gomes ◽  
Paula Iaschitzki Ferreira ◽  
Roseli Lopes da Costa Bortoluzzi ◽  
Adelar Mantovani
Keyword(s):  
Indicator Species ◽  
Forest Succession ◽  
Floristic Composition ◽  
Permanent Plots ◽  
Forest Fragments ◽  
Ecological Processes ◽  
Araucaria Forest ◽  
Native Grassland ◽  
Wetland Succession ◽  
Forest Boundary

A busca do conhecimento sobre a expansão das florestas em relação aos ecossistemas associados (campestre e banhado) aborda a presença de fatores ambientais como o fogo e o pastejo, frequentemente descritos como determinantes dos processos ecológicos favoráveis à dinâmica sucessional. Dessa forma, objetivou-se verificar se existem diferenças na composição florística do interior de fragmentos florestais e entre setores de transição floresta-campo e floresta-banhado, bem como identificar espécies indicadoras para cada um desses ambientes. O estudo foi realizado em fragmentos florestais situados nos municípios de Bom Jardim da Serra e Lages (Coxilha Rica), onde foram instaladas duas parcelas permanentes de 50x50 m, subdivididas em setores de 10x10 m, categorizados em três setores: Floresta Ombrófila Mista, transição floresta x campo e transição floresta x banhado. Há dissimilaridade florística entre os fragmentos florestais dos locais e, também, entre os setores de transição (ecótonos). As espécies indicadoras dos ecótonos estão vinculadas ao estágio inicial da sucessão florestal, apresentando potencial para colonização do campo, podendo atuar no início do processo de expansão da fronteira florestal.AbstractFloristic dissimilarity and indicator species of Araucaria Forest and ecotones. The search for knowledge about the expansion of forests in relation to associated ecosystems (native grassland and wetland) addresses the presence of environmental factors such as fire and grazing, often described as determinants of ecological processes in favor of succession dynamics. The objective here was to verify if there are differences among the floristic composition of the interior of forest fragments and transition sectors of forest-native grassland and forest-wetland, as well as to identify indicator species for each of these environments. The research was conducted in forest fragments located in the municipalities of Bom Jardim da Serra and Lages (Coxilha Rica), SC, where we installed two permanent plots of 50x50 m, subdivided into sectors of 10x10 m categorized into three sectors: Araucaria Forest, forest transition x native grassland and forest x wetland transition. There is floristic dissimilarity between the local forest fragments and also between the transition areas (ecotones). The indicator species of ecotones are linked to early stages of forest succession, with potential for colonization of the field, they can operate in the start of the expansion of the forest boundary process.Keywords: Araucaria Forest; native grassland; wetland; succession.

scholarly journals Leaf chemical defences and insect herbivory in oak: accounting for canopy position unravels marked genetic relatedness effects

2020 ◽  
Vol 126 (5) ◽  
pp. 865-872 ◽  
Author(s):  
Elena Valdés-Correcher ◽  
Audrey Bourdin ◽  
Santiago C González-Martínez ◽  
Xoaquín Moreira ◽  
Andrea Galmán ◽  
...  
Keyword(s):  
Genetic Relatedness ◽  
Insect Herbivory ◽  
Tree Canopy ◽  
Pedunculate Oak ◽  
Oak Woodlands ◽  
Chemical Defences ◽  
Canopy Effect ◽  
Canopy Position ◽  
Variation Explained ◽  
Genetic Signal

Abstract Background and Aims Highly controlled experiments document that plant genetic diversity and relatedness can shape herbivore communities and patterns of herbivory. Evidence from the field is, however, scarce and inconsistent. We assessed whether a genetic signal underlying herbivory can be detected in oak woodlands when accounting for variation at smaller (within-tree) and larger (among-stand) scales. Methods We tested relationships between tree genetic relatedness, leaf chemical defences and insect herbivory for different canopy layers in 240 trees from 15 pedunculate oak (Quercus robur) forest stands. We partitioned sources of variability in herbivory and defences among stands, individuals and branches. Key Results Leaf defences, insect herbivory and their relationship differed systematically between the upper and the lower tree canopy. When accounting for this canopy effect, the variation explained by tree genetic relatedness rose from 2.8 to 34.1 % for herbivory and from 7.1 to 13.8 % for leaf defences. The effect was driven by markedly stronger relationships in the upper canopy. Conclusions Our findings illustrate that considerable effects of the host plant genotype on levels of leaf chemical defences and associated insect herbivory can be detected in natural tree populations when within-individual variation is properly accounted for.

scholarly journals EFEITO DA EXPLORAÇÃO NA RIQUEZA FLORÍSTICA E DIVERSIDADE EM UMA FLORESTA ECOTONAL DA REGIÃO NORTE MATO-GROSSENSE

FLORESTA ◽  
2011 ◽  
Vol 41 (2) ◽  
Author(s):  
Chirle Colpini ◽  
Versides Sebastião de Moraes e Silva ◽  
Thelma Shirlen Soares ◽  
José Vespasiano Lisboa Assumpção ◽  
Roberto Chiaranda
Keyword(s):  
Species Diversity ◽  
Floristic Composition ◽  
Wiener Index ◽  
Northern Region ◽  
Floristic Diversity ◽  
Mato Grosso ◽  
Floristic Richness ◽  
Before And After ◽  
Logged Forest ◽  
Southern Amazonia

O objetivo deste estudo foi avaliar as mudanças ocorridas na riqueza e diversidade de espécies em uma floresta ecotonal na região norte mato-grossense. Os dados foram coletados em três ocasiões (2001, antes da exploração, e em 2003 e 2007, após a exploração), em 74 parcelas de 0,25 ha, sendo 69 para estudar a floresta não explorada e 5 para a explorada, com a retirada dos fustes de árvores com diâmetros comercialmente aceitos no mercado. Todos os indivíduos com diâmetro a 1,3 m de altura do solo (Dap) ≥ 17 cm foram mensurados e identificados. A diversidade florística foi avaliada por meio do quociente de mistura de Jentsch e pelo índice de Shannon-Wiener e a equabilidade pelo índice de Pielou. A variação da riqueza e diversidade de espécies antes e após a exploração madeireira foi pequena, o que confirma o baixo impacto da exploração na composição e diversidade das espécies da floresta.Palavras-chave: Diversidade; equabilidade; Amazônia Meridional. AbstractLogging effects on floristic richness and species diversity in an ecotonal forest in northern region of Mato Grosso state, Brazil. The aim of this research was to evaluate changes in relation to floristic richness and species diversity in an ecotonal forest in northern region of Mato Grosso State, Brazil. Data had been collected along three different moments (2001 [before logging], in 2003 and 2007 [after logging]) in 74 0.25-ha plots (69 in unlogged forest and 5 in logged forest). Trees with diameter ≥ 17 cm and 1.3 m height (dbh) had been measured and identified. Floristic diversity was evaluated by Jentsch Coefficient of Mixture and Shannon-Wiener index as well as its equability by Pielou’s Index. There were little variations before and after logging in relation to floristic richness and species diversity, it confirms low impact of exploration on floristic composition and species diversity of the forest.Keywords: Diversity; equability; Southern Amazonia. 

Scattered native trees and soil patterns in grazing land on the Northern Tablelands of New South Wales, Australia

Soil Research ◽  
2007 ◽  
Vol 45 (3) ◽  
pp. 199 ◽  
Author(s):  
Brian R. Wilson ◽  
Ivor Growns ◽  
John Lemon
Keyword(s):  
New South ◽  
New South Wales ◽  
Tree Canopy ◽  
Deep Drainage ◽  
Grazing Land ◽  
Near Surface ◽  
Soil Layers ◽  
South Wales ◽  
Eastern Australia ◽  
Canopy Effect

Over large areas of south-eastern Australia, the original cover of native woodland has been extensively cleared or modified, and what remains is often characterised by scattered trees beneath which the ground-storey vegetation is largely grazed or otherwise managed. This study investigated the influence of scattered Blakely’s red gum (Eucalyptus blakelyi) trees on both near-surface and deeper soil layers in temperate grazed pastures on the Northern Tablelands of New South Wales, Australia. A significant canopy effect was observed with elevated soil pH, carbon, and nutrient status inside the tree canopy indicating soil enrichment in a zone around the tree. This effect, however, was largely restricted to the surface (0–0.20 m) soil layers. Chloride concentrations were elevated near to trees but only in the deeper soil layers, suggesting that a modified water use and deep drainage mechanism occurred near the trees. Close to the tree, however, a significant acidification was observed between 0.40–0.60 m depth in the soil, without any obvious depletion in other soil element concentrations. It is concluded that this acidification provides strong evidence in support of a ‘biological pumping’ mechanism that has been proposed elsewhere. Key questions remain as to the management implications of these results, whether the subsurface acidification that was observed is common among native Australian trees, if it might be persistent through time, and if this might be a soil issue that requires management.

scholarly journals Stem Flow, Throughfall, and Canopy Interception of Rainfall by Citrus Tree Canopies

HortScience ◽  
1997 ◽  
Vol 32 (6) ◽  
pp. 1059-1160 ◽  
Author(s):  
Y.C. Li ◽  
A.K. Alva ◽  
D.V. Calvert ◽  
M. Zhang
Keyword(s):  
Tree Canopy ◽  
Storm Event ◽  
Citrus Paradisi ◽  
Citrus Tree ◽  
Canopy Interception ◽  
Canopy Effect ◽  
Tree Canopies ◽  
Stem Flow ◽  
Citrus Cultivar ◽  
Rain Events

It is generally believed that the interception of rain by the citrus tree canopy can substantially decrease the throughfall under the canopy as compared to that along the dripline or outside the canopy (incident rainfall). Therefore, the position of placement of soil-applied agrichemicals in relation to the tree canopy may be an important consideration to minimize their leaching during rain events. In this study, the distributions of rainfall under the tree canopies of three citrus cultivars, `Marsh' grapefruit (Citrus paradisi Macf.), `Hamlin' orange (Citrus sinensis L. Osbeck), and `Temple' orange (Citrus hybrid), were evaluated at four directions (north, south, east, west), two positions (dripline and under the canopy), and stem flow. There was not a significant canopy effect on rainfall amounts from stem flow or dripline, compared with outside canopy, for any citrus cultivar or storm event. However, throughfall varied significantly among the four cardinal directions under the canopy of all three citrus cultivars and was highly related to the wind direction. Among the three citrus cultivars evaluated in this study, throughfall, stem flow, and canopy interception accounted for 89.5% to 92.7%, 0.5% to 4.7%, and 5.8% to 9.3% of the incident rainfall, respectively.

scholarly journals Physical Model Test for Soft Soil With or Without Prefabricated Vertical Drain with Loading

2018 ◽  
Vol 4 (8) ◽  
pp. 1809
Author(s):  
Dao Huu Do ◽  
Nguyen Thi Phuong Khue ◽  
Phan Khac Hai
Keyword(s):  
Numerical Simulation ◽  
Physical Model ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Physical Model Test ◽  
Soil Parameters ◽  
Vertical Drain ◽  
Prefabricated Vertical Drain ◽  
Before And After

The paper builds a physical model of testing in the laboratory with the parametric tempered glass box 0.5  0.5 1.2 m (length  width  depth) containing saturated clay to study the settlement and consolidation when loading increased gradually over time. The research covers herein to present the monitoring of settlement and pore water pressure, settlement calculation, numerical simulation using PLAXIS software V8.2 based on the results of soil physical and mechanical tests before and after loading in case of having or not prefabricated vertical drain (PVD). In case of no PVD, the calculation and numerical simulation using the soil parameters before loading have the differential settlement from the monitoring data, approximately 3.86 mm (10.45%), 0.41 mm (1.11%) respectively. Meanwhile, the deviation in the case using data after loading is about 2.29 mm (6.20%), 0.21 mm (0.56%) respectively. In case of PVD, the calculation and numerical simulation with the testing result of before loading deviation from the settlement monitoring by subsidence meter is 2.91 mm (7.88%), 44.42 mm (120.28%), calculation and simulation with the testing result of after loading deviation is 0.80 mm (2.17%), 1.26 mm (3.41%). In the case of having PVD, the difference in calculation, subsidence observation, and numerical simulation between the mechanical properties before and after loading is significant, when using the mechanical data after loading then the results are quite close to the subsidence of observation and simulation rather than before loading. 

scholarly journals The influence of preparation methodology on the concentrations of heavy metals in Pleurozium schreberi moss samples prior to use in active biomonitoring studies

2020 ◽  
Author(s):  
Paweł Świsłowski ◽  
Grzegorz Kosior ◽  
Małgorzata Rajfur
Keyword(s):  
Heavy Metals ◽  
Indicator Species ◽  
Urban Areas ◽  
Absorption Spectrometry ◽  
Tree Canopy ◽  
Wilcoxon Test ◽  
Pleurozium Schreberi ◽  
Active Biomonitoring ◽  
Forested Areas ◽  
Simultaneous Conditioning

Abstract Active biomonitoring is used to assess environmental pollution of elements such as heavy metals by indicator species such as mosses. They are used, among others, in urbanized areas where no indicator species are found. In such study areas, mosses collected from sites considered to be ecologically clean shall be exposed. In this context, it is very important to prepare the mosses properly before the exposure, so that the information received about the condition of the environment is reliable. In 2018, studies were conducted in the forested areas of southern Poland—in Opolskie Province. Pleurozium schreberi mosses were used in these studies. Atomic absorption spectrometry with flame atomiser (F-AAS) was used to determine the concentrations of Mn, Fe, Ni, Cu, Zn and Pb present. The aim was to study the influence of preparation methodology on Pleurozium schreberi moss samples prior to use in active biomonitoring studies. Four different methodologies were tested across four different sample locations (with varying levels of pollution). The results of the research were analysed and the coefficient of variation (CV) was determined. The value of the CV is influenced, among other things, by the location of the particular sample and the level of pollution by, for example heavy metals, in the moss. The research conducted proves that of the four methods used to prepare mosses for later exposure in active biomonitoring, the best method is averaging with simultaneous conditioning of mosses in demineralised water. This treatment causes the CV coefficient to fall below 10% for most of the metals determined in the moss samples. It has also been shown that maintaining moss collection methodology in accordance with ICP Vegetation standards (open/wooded area—tree canopy) also has a significant impact on the result obtained. Statistical analysis confirmed (Wilcoxon test) that the method of processing the mosses significantly influenced the results obtained. Thanks to the appropriate preparation of the mosses before exposition, they can be used in active biomonitoring of, for example, urban areas.

scholarly journals An Inventory of the Aquatic and Subaquatic Plants in SASKWater Canals in Central Saskatchewan, Canada, Before and After the Application of the Herbicide Magnacide

2007 ◽  
Vol 121 (2) ◽  
pp. 164 ◽  
Author(s):  
J. Hugo Cota-Sánchez ◽  
Kirsten Remarchuk
Keyword(s):  
Green Algae ◽  
Plant Density ◽  
Irrigation System ◽  
Floristic Composition ◽  
Ceratophyllum Demersum ◽  
Minor Effect ◽  
Long Term Effects ◽  
Terrestrial Plants ◽  
Myriophyllum Sibiricum ◽  
Before And After

This study focuses on the floristic composition of aquatic and semi-aquatic plants in the SASKWater canal system and their potential effect on irrigation systems. A checklist, evaluation, and synthesis of the species identified in this survey before and after the application of the herbicide Magnacide are provided, in addition to a brief discussion of the environmental effects of Magnacide. Thirty-three species in 26 genera within 20 plant families were identified. Two unidentified green algae were also collected. Common aquatics (i.e., green algae, Potamogeton spp., Alisma gramineum, A. plantago-aquatica, Ceratophyllum demersum, and Myriophyllum sibiricum) combined with debris from terrestrial plants were the primary contributors to blockage of irrigation drains. In general, the concentration of Magnacide used in this study had a minor effect on aquatic plant diversity, but effectively reduced plant density. However, the long-term effects of pesticides on the surrounding aquatic and terrestrial environments of the SASKWater irrigation system are unknown.

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