Effect of microsites on the survival, density, and ectomycorrhizal status of shade-tolerant Abies alba regeneration attacked by fungal pathogens

2012 ◽  
Vol 42 (4) ◽  
pp. 720-732 ◽  
Author(s):  
Jarosław G. Paluch ◽  
Hanna J. Stępniewska
Keyword(s):  
Spatial Distribution ◽  
Natural Regeneration ◽  
Fungal Pathogen ◽  
Fungal Pathogens ◽  
Abies Alba ◽  
Spatial Differentiation ◽  
Stand Density ◽  
Canopy Openness ◽  
Vegetation Control ◽  
Survival Density

An increased incidence of fungal pathogens has been recognized as one of the most important causes for insufficient natural regeneration in pure Abies alba Mill. forests in the Western Carpathians (central Europe). We investigated the spatial distribution of A. alba seedlings in seven stands in which severe symptoms of fungal pathogen infections were observable and compared microsite variables and ectomycorrhizal status of seedlings in locations with abundant or poor regeneration. We also tested the effect of local stand density, seedbed, and vegetation control on seed germination and the survival of 1-year seedlings. The study provided evidence that gap environment may increase the mortality of 1-year seedlings caused by fungal pathogens. That pattern was consistent with the spatial distribution of older seedlings: locations with abundant older regeneration were characterized by a greater local stand density, lower canopy openness, and lower mineral topsoil moisture than poorly regenerated locations. Yet, despite considerable spatial differentiation in ectomycorrhizal types, the mycorrhizal status of 2-year seedlings in abundantly regenerated areas did not differ from that in poorly regenerated areas.

scholarly journals The influence of fencing on seedling establishment during reforestation of oak stands: a comparison of artificial and natural regeneration techniques including costs

2021 ◽  
Author(s):  
Magnus Löf ◽  
Julien Barrere ◽  
Mattias Engman ◽  
Linda K. Petersson ◽  
Adrian Villalobos
Keyword(s):  
Natural Regeneration ◽  
Recruitment Rate ◽  
Direct Seeding ◽  
Vegetation Control ◽  
Efficient Regeneration ◽  
Temperate Europe ◽  
Cost Efficient ◽  
Positive Effect ◽  
Establishment Rate ◽  
Block Experiment

AbstractIn temperate Europe, oak-dominated forests are widespread, supporting high biodiversity and providing important ecosystem services. Insufficient natural regeneration has, however, been a concern for over a century. The objective of this study was to gain insights into differences in regeneration success using artificial and natural regeneration techniques for reforestation of oak (Quercus robur L.) stands. We monitored seedlings following planting, direct seeding and natural regeneration over five years in a randomized block experiment in southern Sweden with fenced and non-fenced plots. Fencing had a strong positive effect on height growth, especially for planted seedlings that were taller than the other seedlings and more frequently browsed in non-fenced plots. In contrast, there was little effect of fencing on survival, establishment rate and recruitment rate of seedlings. Due to aboveground damage on seedlings from voles, protection of acorns did not improve establishment rate following direct seeding. Under current circumstances at the site with a sparse shelterwood of old oaks, we conclude that natural regeneration was the most cost-efficient regeneration method. It resulted in the most seedlings at the lowest cost. However, regeneration success was heavily influenced by interference from herbaceous vegetation. With a small additional investment in vegetation control, the results might have been improved for planting and direct seeding.

Nanoscale adhesion forces between the fungal pathogen Candida albicans and macrophages

2016 ◽  
Vol 1 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Sofiane El-Kirat-Chatel ◽  
Yves F. Dufrêne
Keyword(s):  
Atomic Force Microscopy ◽  
Candida Albicans ◽  
Immune Cells ◽  
Fungal Pathogen ◽  
Fungal Pathogens ◽  
Adhesion Forces ◽  
Force Microscopy ◽  
Atomic Force

We establish atomic force microscopy as a new nanoscopy platform for quantifying the forces between fungal pathogens and immune cells.

scholarly journals Characteristics and factors influencing the natural regeneration of Larix principis-rupprechtii seedlings in northern China

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12327
Author(s):  
Weiwen Zhao ◽  
Wenjun Liang ◽  
Youzhi Han ◽  
Xi Wei
Keyword(s):  
Spatial Distribution ◽  
Natural Regeneration ◽  
Pair Correlation ◽  
Principal Component ◽  
Northern China ◽  
Point Pattern Analysis ◽  
Point Pattern ◽  
Adult Trees ◽  
Herb Diversity ◽  
Univariate Distribution

Larix principis-rupprechtii is an important and widely distributed species in the mountains of northern China. However, it has inefficient natural regeneration in many stands and difficulty recruiting seedlings and saplings. In this study, we selected six plots with improved naturally-regenerated L. principis-rupprechtii seedlings. A point pattern analysis (pair-correlation function) was applied to identify the spatial distribution pattern and correlation between adult trees and regenerated seedlings mapped through X/Y coordinates. Several possible influencing factors of L. principis-rupprechtii seedlings’ natural regeneration were also investigated. The results showed that the spatial distribution patterns of Larix principis-rupprechtii seedlings were concentrated 0–5 m around adult trees when considering the main univariate distribution type of regeneration. There was a positive correlation at a scale of 1.5–4 m between seedlings and adult trees according to bivariate analyses. When the scale was increased, these relationships were no longer significant. Generally, adult trees raised regenerated L. principis-rupprechtii seedlings at a scale of 1.5–4 m. Principal component analysis showed that the understory herb diversity and litter layer had a negative correlation with the number of regenerated seedlings. There was also a weak relationship between regenerated numbers and canopy density. This study demonstrated that the main factors promoting natural regeneration were litter thickness, herb diversity, and the distance between adult trees and regenerated seedlings. Additionally, these findings will provide a basis for the late-stage and practical management of natural regeneration in northern China’s mountain ranges.

scholarly journals Factors Influencing the Natural Forest Regeneration at Khadimnagar National Park, Bangladesh

2021 ◽  
Vol 11 (1) ◽  
pp. 73-83
Author(s):  
MAHEDI HASAN LIMON ◽  
SAIDA HOSSAIN ARA ◽  
MOHAMMAD GOLAM KIBRIA
Keyword(s):  
Species Richness ◽  
Bulk Density ◽  
Total Variation ◽  
Soil Ph ◽  
Tree Species ◽  
Natural Regeneration ◽  
National Park ◽  
Canopy Openness ◽  
Site Factors ◽  
Tree Species Richness

Natural regeneration is an indicator of a healthy forest, hence, understanding the influence of site factors on natural regeneration is a significant concern for ecologists. This work aimed to assess the impact of site factors on natural tree regeneration at Khadimnagar National Park (KNP). Biotic factors (tree density, tree species richness, and basal area), physical factors (elevation, canopy openness), and soil properties (bulk density, moisture content, soil pH, organic matter, sand, silt, and clay) data were investigated from 71 sample plots to examine their effects on natural regeneration density and richness in KNP. Stepwise multiple linear regression analysis was done to predict both regeneration density and regeneration richness. The results showed that soil pH (p<0.001), canopy openness (p<0.001), tree species richness (p<0.01), and bulk density (p<0.01) had a significant effect on regeneration density, explaining 42% of the total variation. Regeneration richness was driven by four factors: tree species richness (p<0.01), soil pH (p<0.001), elevation (p<0.01), and canopy openness (p<0.01) with a model that explained 60% of the total variation. This study observed that soil pH, tree species richness, and canopy openness are the main controlling factors that influenced both the density and richness of regenerating species in KNP. Therefore, these findings have implications for natural resource management, especially in selecting suitable silvicultural systems in a tropical forest under protected area management where enhanced tree cover and conservation of biodiversity are needed.

scholarly journals IDENTIFIKASI DAN UJI PATOGENISITAS CENDAWAN ENTOMOPATOGEN LOKAL TERHADAP Leptocorisa oratorius

EUGENIA ◽  
2011 ◽  
Vol 17 (3) ◽  
Author(s):  
Emmy Senewe ◽  
Guntur Manengkey
Keyword(s):  
Fungal Pathogen ◽  
Fungal Pathogens ◽  
Pathogenic Fungus ◽  
Pathogenic Fungi ◽  
North Sulawesi ◽  
Pathogenicity Tests ◽  
Major Pest ◽  
White Mycelium ◽  
Fusarium Sp ◽  
Leptocorisa Oratorius

ABSTRACT Leptocorisa oratorius is one major pest of rice in North Sulawesi. Hence, it is necessary to control the pest. The research objective was to identify and to test pathogenicity of local  entomopathogen fungi which infected  Leptocorisa oratorius. The pathogens were collected through sampling of L. oratorius which had been infected by the fungi in the field. The pathogenic fungi was isolated using PDA medium, identified followed by inoculation for pathogenecity test.  During several sampling pest, it was found that  L. oratorius was attacked by fungal pathogens in the field. The identification revelead that the fungal pathogens were Beauveria sp and Fusarium sp. Both the fungal pathogen produced white mycelium and could only be distinguished using microscope in the laboratory. Result of pathogenicity tests showed that the two fungal pathogens caused different mortality of the L. oratorius. Mortality of  L. oratorius caused by pathogenic fungus Beauveria sp was  30.3% . Whereas, mortality of  L. oratorius caused by Fusarium sp was only 3.33%. Keywords : pathogenic fungi, entomopathogen, pathogenicity tests, L. oratorius

Apical dominance ratio as an indicator of the growth conditions favouring Abies alba natural regeneration under Mediterranean environment

2016 ◽  
Vol 135 (2) ◽  
pp. 377-387 ◽  
Author(s):  
Francesco Ripullone ◽  
Tiziana Gentilesca ◽  
Marco Lauteri ◽  
Angelo Rita ◽  
Anna Rita Rivelli ◽  
...  
Keyword(s):  
Apical Dominance ◽  
Natural Regeneration ◽  
Abies Alba ◽  
Growth Conditions ◽  
Mediterranean Environment ◽  
Dominance Ratio

scholarly journals The influence of stand canopy openness on the growth of common yew (Taxus baccata L.)

2015 ◽  
Vol 76 (1) ◽  
pp. 42-48 ◽  
Author(s):  
Marzena Niemczyk ◽  
Anna Żółciak ◽  
Wrzesiński Piotr
Keyword(s):  
Light Transmission ◽  
Abies Alba ◽  
Extended Period ◽  
European Beech ◽  
Ex Situ ◽  
Canopy Openness ◽  
Silver Fir ◽  
Taxus Baccata ◽  
Height Increment ◽  
Transmission Index

Abstract The aim of this study was to evaluate the development of common yew, Taxus baccata L., with respect to canopy openness. The plants were growing in ex-situ conservation plantations (established in 2008) in the understory of different tree species. Eleven forest plantations belonging to the following five forest districts were inventoried: Rokita, Baligród, Kołaczyce, Międzylesie and Henryków. In each plantation, the height and height increment of 200 yews were measured and gap light transmission indices were determined. The canopy species affecting yew growth most significantly were oak (Quercus sp.) and Scots pine (Pinus sylvestris L.), followed by Norway spruce (Picea abies Karst.), silver fir (Abies alba L.) and European beech (Fagus sylvatica L.). The most favorable development of yew occurred at 30% canopy openness. An increasing light transmission index correlated with a decrease in the proportion of treelike yews. An insufficient amount of light resulted in a low height increment of yews growing under the canopy and an extended period of direct competition of yews with herbaceous species.

scholarly journals Characteristics and Influencing Factors of Spatial Differentiation of Urban Black and Odorous Waters in China

2018 ◽  
Vol 10 (12) ◽  
pp. 4747 ◽  
Author(s):  
Guolei Chen ◽  
Jing Luo ◽  
Chunyan Zhang ◽  
Liang Jiang ◽  
Lingling Tian ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Sewage Treatment ◽  
Water Environment ◽  
Spatial Differentiation ◽  
Urban Pollution ◽  
Influential Factors ◽  
Joint Control ◽  
Chinese Government ◽  
Analysis Tool ◽  
Gradient Distribution

The pollution problem caused by urban black and odorous waters has received much attention from the Chinese government. Our research aims at systematically identifying the characteristics and the influential factors of spatial differentiation of urban black and odorous waters across China. The research, based on the data of black and odorous waters from 2100 Chinese cities, was conducted with the spatial analysis tool of ArcGIS. We found that the amount of Chinese urban black and odorous waters varied in spatial distribution, which was an agglomerated type with significant agglomeration. The kernel density was characterized by independent single kernel centers with ribbon-like and sporadic distributions of subcenters. The cold and hot spots showed a gradient distribution pattern of cold in the southwest and hot in the central east. These spatial distribution characteristics could be attributed to the following core factors, total wastewater discharge, length of urban drainage pipelines, municipal solid waste collection, daily urban sewage treatment capacity, and investment in urban pollution treatment of wastewater. The findings reveal the current geospatial distribution of black and odorous waters pollution and provide reference for the Chinese government to treat the pollution from several key points. Lastly, it is suggested that the Chinese government should establish joint control, joint prevention, and joint treatment mechanisms in the black and odorous waters areas and improve the safety standards of the whole water environment, so as to promote the treatment and elimination of urban black and odorous waters.

scholarly journals The ALMA-PILS survey: inventory of complex organic molecules towards IRAS 16293–2422 A

2020 ◽  
Vol 635 ◽  
pp. A48 ◽  
Author(s):  
S. Manigand ◽  
J. K. Jørgensen ◽  
H. Calcutt ◽  
H. S. P. Müller ◽  
N. F. W. Ligterink ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Organic Molecules ◽  
Rotational Temperature ◽  
Line Strength ◽  
Spatial Differentiation ◽  
Complex Species ◽  
Ethyl Methyl ◽  
Compact Region ◽  
Many Sources ◽  
Complex Organic

Context. Complex organic molecules are detected in many sources in the warm inner regions of envelopes surrounding deeply embedded protostars. Exactly how these species form remains an open question. Aims. This study aims to constrain the formation of complex organic molecules through comparisons of their abundances towards the Class 0 protostellar binary IRAS 16293–2422. Methods. We utilised observations from the ALMA Protostellar Interferometric Line Survey of IRAS 16293–2422. The species identification and the rotational temperature and column density estimation were derived by fitting the extracted spectra towards IRAS 16293–2422 A and IRAS 16293–2422 B with synthetic spectra. The majority of the work in this paper pertains to the analysis of IRAS 16293–2422 A for a comparison with the results from the other binary component, which have already been published. Results. We detect 15 different complex species, as well as 16 isotopologues towards the most luminous companion protostar IRAS 16293–2422 A. Tentative detections of an additional 11 isotopologues are reported. We also searched for and report on the first detections of methoxymethanol (CH3OCH2OH) and trans-ethyl methyl ether (t-C2H5OCH3) towards IRAS 16293–2422 B and the follow-up detection of deuterated isotopologues of acetaldehyde (CH2DCHO and CH3CDO). Twenty-four lines of doubly-deuterated methanol (CHD2OH) are also identified. Conclusions. The comparison between the two protostars of the binary system shows significant differences in abundance for some of the species, which are partially correlated to their spatial distribution. The spatial distribution is consistent with the sublimation temperature of the species; those with higher expected sublimation temperatures are located in the most compact region of the hot corino towards IRAS 16293–2422 A. This spatial differentiation is not resolved in IRAS 16293–2422 B and will require observations at a higher angular resolution. In parallel, the list of identified CHD2OH lines shows the need of accurate spectroscopic data including their line strength.

scholarly journals Growth, Biomass Production and Root Development of Chinese fir in Relation to Initial Planting Density

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 236 ◽  
Author(s):  
Taimoor Farooq ◽  
Wenjing Wu ◽  
Mulualem Tigabu ◽  
Xiangqing Ma ◽  
Zongming He ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Biomass Production ◽  
Stand Density ◽  
Tree Height ◽  
Root Systems ◽  
Chinese Fir ◽  
High Density ◽  
Planting Density ◽  
Low Density ◽  
Intermediate Density

Chinese fir (Cunninghamia lanceolata (Lamb) Hook) is a commercially valuable timber species that is widely planted in southern China and accounts for 6.1% of the global plantation forests. However, appropriate planting density that ensures high plantation productivity is largely unexplored in this species. The aim of the study was to examine tree growth, biomass production, and its allocation among different organs in relation to initial planting density, and to examine whether planting density has an impact on root development. Mortality, diameter at breast height and tree-height of all trees were determined and measured in wider (2.36 × 2.36 m), intermediate (1.83 × 1.83 m) and narrow (1.44 × 1.44 m) spacing with stand density of 1450 trees ha−1, 2460 trees ha−1 and 3950 trees ha−1, respectively. In each stand, three plots of 20 × 20 m at a distance of 500 m were delineated as the sampling unit. Biomass was determined by destructive sampling of trees in each stand and developing allometric equations. Root morphological traits and their spatial distribution were also determined by carefully excavating the root systems. The results showed an increase in diameter of trees with decreasing stand density while tree height was independent of stand density. Biomass production of individual trees was significantly (p < 0.05) less in high-density stand (32.35 ± 2.98 kg tree−1) compared to low-density stand (44.72 ± 4.96 kg tree−1) and intermediate-density stand (61.35 ± 4.78 kg tree−1) while stand biomass production differed significantly in the order of intermediate (67.63 ± 5.14 t ha−1) > high (57.08 ± 3.13 t ha−1) > low (27.39 ± 3.42 t ha−1) stand density. Both average root length and root volume were significantly (p < 0.05) lower in the high-density stand than stands with low and intermediate density. Analysis of spatial distribution of root systems revealed no overlap between roots of neighboring trees in the competition zone in low-density stand, a subtle overlap in the intermediate density stand and larger overlap in the high-density stand. It can be concluded that better growth and biomass production in intermediate density stand could be explained by better root structural development coupled with minimal competition with understory vegetation and between trees; thus intermediate stand density can be optimal for sustaining long-term productivity and may reduce the management cost in the early phase of the plantation.

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