scholarly journals Insect herbivory and avian insectivory in novel native oak forests: divergent effects of stand size and connectivity

2019 ◽  
Author(s):  
Elena Valdés-Correcher ◽  
Inge van Halder ◽  
Luc Barbaro ◽  
Bastien Castagneyrol ◽  
Arndt Hampe
Keyword(s):  
Insect Herbivory ◽  
Oak Forests ◽  
Suitable Habitat ◽  
Native Forest ◽  
Minor Effect ◽  
Insect Herbivores ◽  
Pedunculate Oak ◽  
Forest Stands ◽  
Leaf Miners ◽  
Rural Landscapes

AbstractThe value of novel native broadleaf woodlands for biodiversity conservation is important to consider for adequate forest management in rural landscapes. Passive reforestation has been proposed as a cost-efficient tool for creating networks of novel native forest stands that would help restoring biodiversity and associated ecosystem services. Yet to date the ecological functioning of such stands remains strongly understudied compared to forest remnants resulting from longer-term fragmentation. We assessed how the size and connectivity of newly established Pedunculate oak (Quercus robur L.) stands in rural landscapes of SW France affect rates of herbivory by different insect guilds as well as rates of avian insectivory and the abundance and richness of insectivorous birds. Comparing 18 novel forest stands along a gradient of size (0.04-1.15 ha) and cover of broadleaf forests in the surroundings (0-30% within a 500 radius), we found that even the smallest stands are colonised by leaf miners and chewers/skeletonizers, and that rates of herbivory are globally comparable to those reported from older and larger oak forests. The size of stands had a relatively minor effect on herbivory, whereas it increased the abundance of insectivorous bird. It also determined rates of avian insectivory as estimated by an experiment with plasticine caterpillars. These rates were however rather low and unrelated with the extent of herbivory in the stand. Overall, our study indicates that insect herbivores tend to react more rapidly to the establishment of novel native forests than their avian predators as the latter may depend on the development of larger patches of suitable habitat in the surrounding landscape. To favour a rapid build-up of diverse, and hence stable, trophic networks involving insect herbivores and their predators, woodland creation schemes should therefore primarily focus on habitat size and quality.

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 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.

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 Host specificity of insect herbivores in tropical forests

2005 ◽  
Vol 272 (1568) ◽  
pp. 1083-1090 ◽  
Author(s):  
Vojtech Novotny ◽  
Yves Basset
Keyword(s):  
Host Specificity ◽  
Tropical Forests ◽  
Plant Species ◽  
Field Studies ◽  
Tropical Species ◽  
Distribution Data ◽  
Insect Herbivores ◽  
Leaf Miners ◽  
Experimental Conditions ◽  
Plant Phylogeny

Studies of host specificity in tropical insect herbivores are evolving from a focus on insect distribution data obtained by canopy fogging and other mass collecting methods, to a focus on obtaining data on insect rearing and experimentally verified feeding patterns. We review this transition and identify persisting methodological problems. Replicated quantitative surveys of plant–herbivore food webs, based on sampling efforts of an order of magnitude greater than is customary at present, may be cost-effectively achieved by small research teams supported by local assistants. Survey designs that separate historical and ecological determinants of host specificity by studying herbivores feeding on the same plant species exposed to different environmental or experimental conditions are rare. Further, we advocate the use of host‐specificity measures based on plant phylogeny. Existing data suggest that a minority of species in herbivore communities feed on a single plant species when alternative congeneric hosts are available. Thus, host plant range limits tend to coincide with those of plant genera, rather than species or suprageneric taxa. Host specificity among tropical herbivore guilds decreases in the sequence: granivores>leaf-miners>fructivores>leaf-chewers=sap-suckers>xylophages>root-feeders, thus paralleling patterns observed in temperate forests. Differences in host specificity between temperate and tropical forests are difficult to assess since data on tropical herbivores originate from recent field studies, whereas their temperate counterparts derive from regional host species lists, assembled over many years. No major increase in host specificity from temperate to tropical communities is evident. This conclusion, together with the recent downward revisions of extremely high estimates of tropical species richness, suggest that tropical ecosystems may not be as biodiverse as previously thought.

scholarly journals Rhizosphere microbes and host plant genotype influence the plant metabolome and reduce insect herbivory

2018 ◽  
Author(s):  
Charley J. Hubbard ◽  
Baohua Li ◽  
Robby McMinn ◽  
Marcus T. Brock ◽  
Lois Maignien ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Flea Beetle ◽  
Insect Herbivory ◽  
Amplicon Sequencing ◽  
Plant Performance ◽  
Insect Herbivores ◽  
List Type ◽  
Plant Genotype ◽  
Herbivore Resistance ◽  
Rhizosphere Microbiome

SummaryRhizosphere microbes affect plant performance, including plant resistance against insect herbivores; yet, the relative influence of rhizosphere microbes vs. plant genotype on herbivory levels and on metabolites related to defense remains unclear.In Boechera stricta, we tested the effects of rhizosphere microbes and plant genotype on herbivore resistance, the primary metabolome, and select secondary metabolites.Plant populations differed significantly in the concentrations of 6 glucosinolates (GLS), secondary metabolites known to provide herbivore resistance in the Brassicaceae, and the population with lower GLS levels experienced ~60% higher levels of aphid (Aphis spp.) attack; no effect was observed of GLS on damage by a second herbivore, flea beetles (Altica spp.). Rhizosphere microbiome (intact vs. disrupted) had no effect on plant GLS concentrations. However, aphid number and flea beetle damage were respectively ~3-fold and 7-fold higher among plants grown in the disrupted rhizosphere microbiome treatment, and distinct (as estimated from 16s rRNA amplicon sequencing) intact native microbiomes also differed in their effects on herbivore damage. These differences may be attributable to shifts in primary metabolic pathways.The findings suggest that rhizosphere microbes can play a greater role than plant genotype in defense against insect herbivores, and act through mechanisms independent of plant genotype.

scholarly journals Disturbances and biodiversity in forest ecosystems: A temperate zone perspective

2012 ◽  
Vol 8 ◽  
pp. 1-9 ◽  
Author(s):  
Anton Fischer
Keyword(s):  
Forest Management ◽  
Bark Beetle ◽  
Forest Ecosystems ◽  
Temperate Zone ◽  
Permanent Plots ◽  
Native Forest ◽  
Main Task ◽  
Natural Disturbances ◽  
Forest Stands ◽  
Biodiversity Protection

In the temperate zone windstorms and bark beetle attacks represent the main natural forest disturbances; in steep mountain areas snow avalanches also may “destroy” forest stands completely. In the densely populated and intensively used temperate zone of Europe affected forest stands will be cleared and reforested immediately after such “catastrophes”. Therefore we have only little knowledge about the influence of such natural disturbances on both the stand development and the biodiversity of native forest ecosystems. And we do not have quantitative data on to which degree forest management changes the biodiversity compared to the natural disturbances. Since about two decades several permanent plot studies have been running in European forests affected by such natural disturbances, mainly with focus on plant species. Here we first outline the importance of disturbances for biodiversity in forest ecosystems and then discuss whether it is possible to combine both biodiversity protection and forest management. For that we use four recent case studies carried out in the two oldest national parks in Germany, three of them being long-term observations on permanent plots for up to two decades. Disturbances like wind throw, bark beetle outbreak and snow avalanche strongly influences the tree layer structure, creating micro-habitats for many plant, animal and fungi species, which naturally belong to the forest ecosystem. Such disturbances in future should be included into management schemes in forestry to improve biodiversity. We found evidence that it is really possible to combine timber utilization with biodiversity protection. As long as the management impact is reduced (e.g. single tree harvesting, using natural regeneration), species diversity of several taxonomic groups (in our study: vascular plants, soil living Carabidae, and soil living fungi) may not be different significantly from a pristine forest. Interconnecting resource use with biodiversity protection will be a main task for both foresters and conservationist in the decades to come – and it seems to be a possible option for a sustainable land use in many parts of the world.doi: http://dx.doi.org/10.3126/botor.v8i0.5552 Botanica Orientalis – Journal of Plant Science (2011) 8: 1-9

scholarly journals Brown oak slender is a long known, but still little studied species

2019 ◽  
Author(s):  
И.А. Уткина ◽  
В.В. Рубцов
Keyword(s):  
Weather Conditions ◽  
Oak Forests ◽  
Operophtera Brumata ◽  
Leaf Miners ◽  
Early Form ◽  
Moth Population ◽  
Winter Moth ◽  
Oak Trees ◽  
European Part Of Russia ◽  
Mass Reproduction

Дубовая широкоминирующая моль Acrocercops brongniardella (Fabricius, 1798) (Lepidoptera, Gracillariidae) давно известный и массово размножающийся в дубравах европейской части России, Украины, странах Западной Европы вид филлофаговминёров. В последние два десятилетия появились свидетельства увеличения её численности в ряде регионов. Вместе с тем до сих пор остаются пробелы в знаниях об особенностях развития этого вида. По мнению одних ученых, моль производит одно поколение в год, других два. Такое расхождение может быть связано с разной погодной ситуацией в разных местообитаниях или изменяющимися условиями одного и того же местообитания. При одновременном массовом размножении дубовой широкоминирующей моли и зимней пяденицы Operophtera brumata (Linnaeus, 1758) (Lepidoptera: Geometridae) дефолиация крон обеих феноформ дуба происходит поразному, что связано с тем, что первичную листву ранней формы дуба, повреждённую зимней пяденицей, моль не заселяет и начинает минировать листья дуба поздней и промежуточных форм, не повреждённых зимней пяденицей, что увеличивает уровень их дефолиации. После окукливания зимней пяденицы, при появлении на раннем дубе нежной вторичной листвы, дубовая широкоминирующая моль успешно её осваивает. Деревья дуба при этом испытывают более продолжительное и интенсивное повреждение листвы разных генераций, что сказывается на их текущем состоянии и дальнейшем развитии. Таким образом, при высокой плотности популяции зимней пяденицы она оказывает определенное давление на популяцию дубовой широкоминирующей моли, лишая её возможности питаться весенней листвой дуба ранней формы. Лёт бабочек дубовой широкоминирующей моли ежегодно продолжительный в течение всего летнего периода он проходит очень неравномерно в разных типах дубрав и существенно зависит от погодных условий. Ее высокая вредоносность сохраняется. Вспышка зимней пяденицы прекратилась после сильных морозов в январе феврале 2012 г. The brown oak slender Acrocercops brongniardella (F., 1798) (Lepidoptera, Gracillariidae) is a wellknown species of leaf miners that has been widely reproducing in oak forests of the European part of Russia, Ukraine, and Western European countries. In the past two decades, evidence of an increase in its abundance and population density in some regions has appeared. However, there are still gaps in knowledge on the development features of this species. According to some authors, the moth produces one generation per year, while other authors indicate two. This discrepancy may be due to different weather conditions in different habitats, or the change in conditions of the same habitat. With simultaneous mass reproduction of the brown oak slender and the winter moth Operophtera brumata (L., 1758) (Lepidoptera: Geometridae), the defoliation of the crowns of both phenological forms of the oak occurs differently, due to the fact that the primary foliage of the early form of the oak damaged by the winter moth, the brown oak slender does not colonize and begins to mine the leaves of the oak of the late and intermediate forms not damaged by the winter moth. This increases the level of defoliation. After pupation of the winter moth, when delicate secondary foliage appears on early oak, the brown oak slender successfully utilizes it. At this point, oak trees experience a more prolonged and intensive damage to the foliage of different generations, which affects their current state and further development. Thus, at a high density of the winter moth population, it exerts a certain pressure on the population of the brown oak slender, depriving it of the opportunity to feed on the spring foliage of the earlyshaped oak. The flight of the brown oak slender is annually long, during the whole summer, but it occurs very unevenly in different types of oak forests and significantly depends on the weather conditions. The damage caused by the brown oak slender is still high. The outbreak of the winter moth stopped after a severe frost in January February of 2012.

THE NEED TO STUDY SILVICULTURAL EFFECTS OF MECHANIZED LOGGING SYSTEMS IN EASTERN CANADA

1965 ◽  
Vol 41 (2) ◽  
pp. 252-256 ◽  
Author(s):  
G. F. Weetman
Keyword(s):  
Nutrient Cycling ◽  
Natural Regeneration ◽  
Native Forest ◽  
Forest Stands ◽  
Eastern Canada ◽  
Tree Crowns

Biological problems which may result from the use of heavy logging equipment are discussed. Scarification from logging rarely produces enough seedbed favourable to natural regeneration. Full-tree logging may cause nutrition problems by removing tree crowns from poor sites. Well designed studies of various kinds of logging systems are needed to assess their effects on the stand, soil and future regeneration. Studies of nutrient cycling in native forest stands might indicate some of the effects of full tree logging.

scholarly journals Pedunculate Oak Leaf Miners’ Community: Urban vs. Rural Habitat

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1300
Author(s):  
Jovan Dobrosavljević ◽  
Čedomir Marković ◽  
Marija Marjanović ◽  
Slobodan Milanović
Keyword(s):  
Species Richness ◽  
Urban Areas ◽  
Habitat Type ◽  
Pedunculate Oak ◽  
Insect Community ◽  
Habitat Types ◽  
Leaf Miners ◽  
Rural And Urban ◽  
Leaf Mining ◽  
Abundance And Diversity

With the process of urbanization, cities are expanding, while forests are declining. Many conditions in the urban habitats are modified compared to those in the rural ones, so the organisms present reactions to these changes. To determine to what extent the habitat type influences insects, we tested the differences in the pedunculate oak (Quercus robur L.) leaf-mining insect community between urban and rural habitats in Serbia. Lower species richness, abundance, and diversity were determined on trees in the urban environment. Due to the differences in the habitat types, many of the species disappeared, while most of the remaining species declined. The seasonal dynamics of species richness, abundance, and diversity differed between the habitat types. Both rural and urban populations started with low values in May. Subsequently, rural populations gained higher species richness, abundance, and diversity. As about 60% of the leaf miners’ species present in the rural habitats survive on the trees in urban areas, those trees are of great importance as a species reservoir. This is why we need to preserve and strive to improve the condition of urban areas where the pedunculate oak is present.

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