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

2019 ◽  
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 ◽  
Forest Stands ◽  
Chemical Defences ◽  
Canopy Effect ◽  
Canopy Position ◽  
Variation Explained ◽  
Genetic Signal

AbstractBackground and AimsHighly controlled experiments revealed that plant genetic diversity and relatedness can shape herbivore communities and patterns of herbivory. Evidence from the field is scarce and inconsistent. We assessed whether a genetic signal underlying herbivory can be detected in oak forest stands when accounting for variation at smaller (within-tree) and larger (among-stand) scales.MethodsWe tested relationships between tree genetic relatedness, leaf chemical defences and insect herbivory at different canopy layers in 240 trees from 15 Pedunculate oak (Quercus robur) forest stands and partitioned sources of variability in herbivory and defences among stands, individuals, and branches.Key ResultsLeaf 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.ConclusionsOur findings illustrate that properly accounting for other sources of variation acting at different scales can reveal potentially relevant effects of the host plant genotype on patterns of leaf chemical defences and associated insect herbivory in natural tree populations.

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.

On the interaction between tree canopy position and environmental effects on soil attributes and plant communities

2015 ◽  
Vol 26 (6) ◽  
pp. 1030-1042 ◽  
Author(s):  
Santiago Soliveres ◽  
David J. Eldridge ◽  
Jonathan D. Müller ◽  
Frank Hemmings ◽  
Heather L. Throop
Keyword(s):  
Plant Communities ◽  
Environmental Effects ◽  
Tree Canopy ◽  
Soil Attributes ◽  
Canopy Position

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 Pecan Kernel Phenolics Content and Antioxidant Capacity Are Enhanced by Mechanical Pruning and Higher Fruit Position in the Tree Canopy

2020 ◽  
Vol 145 (3) ◽  
pp. 193-202
Author(s):  
Yi Gong ◽  
Ronald B. Pegg ◽  
Adrian L. Kerrihard ◽  
Brad E. Lewis ◽  
Richard J. Heerema
Keyword(s):  
High Performance ◽  
Light Exposure ◽  
Antioxidant Properties ◽  
Reversed Phase ◽  
Tree Canopy ◽  
Canopy Height ◽  
Canopy Position ◽  
Phenolics Content ◽  
Bound Phenolics

Pecan (Carya illinoinensis) is a tree nut native to North America. Although inhibited light exposure (most specifically as a result of overlapping tree canopies) has been shown to impair yield, the effect of this factor on nut antioxidant properties remains unknown. This study investigated effects of mechanical pruning and canopy height position of fruit on pecan kernel antioxidant contents and capacity. Beginning in 2006, trees in a ‘Western’ pecan orchard in New Mexico were subjected to three mechanical pruning frequency treatments (annual, biennial, and triennial) paralleling conventional practices, while other trees were maintained as unpruned controls. During the 2012 to 2014 seasons, pecans were sampled at fruit maturity from three canopy height zones (“low,” “middle,” and “high,” corresponding to 1.5 to 3.0 m, 3.0 to 4.5 m, and 4.5 to 6.0 m above the orchard floor). In vitro phenolics contents and antioxidant capacities of the nutmeats were evaluated by total phenolics content (TPC) and oxygen radical absorbance capacity (H-ORACFL), respectively. Soluble ester- and glycoside-bound phenolics were quantified by reversed-phase high-performance liquid chromatography (HPLC). For both TPC and H-ORACFL, results determined pruned samples had significantly higher values than unpruned samples (P < 0.001 for both comparisons), and that samples of “high” canopy height were significantly greater than those of “middle” height, which were in turn greater than those of “low” height (P < 0.001 for all comparisons). HPLC findings showed that in all three phenolic fractions (free, esterified, and glycoside-bound phenolics), nuts acquired from pruned trees had substantially greater concentrations of ellagic acid and its derivatives. Our findings indicate mechanical pruning of pecan trees and higher tree canopy position of fruit increase nut antioxidant properties.

scholarly journals Tree canopy effect on grass and grass/legume mixtures in eastern Nebraska

2009 ◽  
Vol 77 (1) ◽  
pp. 23-35 ◽  
Author(s):  
Michael E. L. Perry ◽  
Walter H. Schacht ◽  
Gregory A. Ruark ◽  
James R. Brandle
Keyword(s):  
Tree Canopy ◽  
Canopy Effect

scholarly journals Fruit canopy position and harvest date influence on colour and quality of Imperial mandarin (Citrus reticulata Blanco)

2020 ◽  
pp. 660-666
Author(s):  
Prakash Adhikari ◽  
Zora Singh ◽  
Vijay Yadav Tokala ◽  
Poe Nandar Kyaw ◽  
Bronwyn Walsh
Keyword(s):  
Block Design ◽  
Quality Parameters ◽  
Tree Canopy ◽  
Harvest Date ◽  
Citrus Reticulata ◽  
Fruit Colour ◽  
Citrus Reticulata Blanco ◽  
Commercial Harvest ◽  
Canopy Position

Rind colour and taste are important factors influencing consumer acceptance of mandarins (Citrus reticulata Blanco) fruit. In this experiment, the influence of fruit canopy position and harvest date on the fruit rind colour and other quality parameters of Imperial mandarins was investigated. The mandarin fruit were harvested from four different positions in the tree canopy i.e., upper-inner, upper-outer, lower-inner and lower-outer and at three different harvest dates (H1 (five days before commercial harvest date); H2 (commercial harvest date) and H3 (five days after commercial harvest date). The experiment was conducted using a two factors (fruit position and harvest time) factorial randomised block design with four replicates and fifteen fruit per replicate. Rind colour and the quality of Imperial mandarins were significantly affected by the fruit position in the tree canopy, with the fruit harvested from the upper canopy having better rind colour and higher levels of organic acids and sugars compared to other positions. The late harvested (H3) mandarins exhibited the best fruit colour. In conclusion, the Imperial mandarin fruit had better fruit colour as well as quality when harvested from the upper canopy and by delaying the fruit harvest date by five days from the original commercial harvest date.

scholarly journals Herbivory on the pedunculate oak along urbanization range in Europe: effects of local forest cover and insect feeding guild

2021 ◽  
Author(s):  
Elena Valdés-Correcher ◽  
Anna Popova ◽  
Andrea Galmán ◽  
Andreas Prinzing ◽  
Andrey Selikhovkin ◽  
...  
Keyword(s):  
Forest Cover ◽  
Interactive Effect ◽  
Insect Herbivory ◽  
Canopy Cover ◽  
Biotic Interactions ◽  
Insect Herbivores ◽  
Pedunculate Oak ◽  
Feeding Guild ◽  
Leaf Miners ◽  
Negative Effect

Urbanization is recognized as an important driver of the diversity and abundance of tree associated insect herbivores, but its consequences for insect herbivory are controversial. A likely source of variability among studies is the insufficient consideration of intra-urban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effect of urbanization and local canopy cover on insect herbivory in the pedunculate oak (Quercus robur) throughout most of its geographic range in Europe. The damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing urbanization around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of urbanization. In contrast, an increase in local canopy cover buffered the negative effect of urbanization on leaf-miners and strengthened its effect on gall-inducers. These results show the complexity of plant-herbivore interactions in urbanized areas, highlighting that the presence of local canopy cover within cities has the potential to attenuate or modify the effect of urbanization on biotic interactions.

scholarly journals Aboveground biomass in norway spruce trees in natural forest stand

2014 ◽  
pp. 150-158
Author(s):  
D. Karabchuk
Keyword(s):  
Norway Spruce ◽  
Aboveground Biomass ◽  
Natural Forest ◽  
Tree Canopy ◽  
Tree Size ◽  
Model Trees ◽  
Mature Phase ◽  
Canopy Position ◽  
Size Variability ◽  
Natural Stands

The article promotes to use tree social classes method for the selections of model trees while evaluate biomass in mature natural forest stands because of tree size variability. Average aboveground biomass of Norway spruce model trees calculated to be 542 ± 42 kg, which accumulate every year 6,1 ± 0,4 kg of dry matter and sequester 2,9 ± 0,2 kg of carbon from the atmosphere. We found a significant effect (α = 0,05) of a tree canopy position on a volume of accumulated biomass. Key words: natural stands, mature phase, Cheremosh watershed, Norway spruce, social class, tree size variability, aboveground biomass, mean annual increments, aboveground biomass components, sequestered carbon.

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