Variation in the Impact of Insect Herbivory on Trifolium Pratense Through Early Plant Succession

1989 ◽  
Vol 77 (2) ◽  
pp. 537 ◽  
Author(s):  
A. C. Gange ◽  
V. K. Brown ◽  
I. M. Evans ◽  
A. L. Storr
2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Martin M. Gossner ◽  
Ludwig Beenken ◽  
Kirstin Arend ◽  
Dominik Begerow ◽  
Derek Peršoh

AbstractPlants can be severely affected by insect herbivores and phytopathogenic fungi, but interactions between these plant antagonists are poorly understood. We analysed the impact of feeding damage by the abundant herbivore Orchestes fagi on infection rates of beech (Fagus sylvatica) leaves with Petrakia liobae, an invasive plant pathogenic fungus. The fungus was not detected in hibernating beetles, indicating that O. fagi does not serve as vector for P. liobae, at least not between growing seasons. Abundance of the fungus in beech leaves increased with feeding damage of the beetle and this relationship was stronger for sun-exposed than for shaded leaves. A laboratory experiment revealed sun-exposed leaves to have thicker cell walls and to be more resistant to pathogen infection than shaded leaves. Mechanical damage significantly increased frequency and size of necroses in the sun, but not in shade leaves. Our findings indicate that feeding damage of adult beetles provides entry ports for fungal colonization by removal of physical barriers and thus promotes infection success by pathogenic fungi. Feeding activity by larvae probably provides additional nutrient sources or eases access to substrates for the necrotrophic fungus. Our study exemplifies that invasive pathogens may benefit from herbivore activity, which may challenge forest health in light of climate change.


2021 ◽  
Author(s):  
◽  
Cielle Stephens

Ecological restoration often involves revegetation. I have investigated the impact of revegetation on the distribution, abundance and body condition of skinks on Stephens Island (Takapourewa). I tested the prediction that only one, Oligosoma infrapunctatum, of the four skink species (Oligosoma lineoocellatum, O. nigriplantare polychroma, O. infrapunctatum andO. zelandicum) will benefit in terms of abundance and distribution from revegetation. Stephens Island is a Wildlife Sanctuary in the north-western Marlborough Sounds, New Zealand. The island is known for its diverse and abundant reptile community. Prior to the mid 19th century Stephens Island was covered in forest. Nearly 80% of this forest was destroyed following the establishment of a lighthouse and farm on the island in 1894. In 1989, when the control of Stephens Island passed to the Department of Conservation, reforestation became a key conservation goal. Stephens Island is currently a mosaic of different habitat types from pasture to coastal forest. Pitfall traps caught skinks for a mark-recapture study in four replicated habitat types: forest, tussock, pasture and replanted.<br><br>Oligosoma lineoocellatum comprised 75% of all individuals caught. Densities of O. lineoocellatum were higher in replanted habitat (3020/ha in December and 3770/ha in March) than tussock (2690/ha in December and 2560/ha in March) and lowest in the pasture (1740/hain December and 1960/ha in March). Rates of captures were too low to perform density estimates for the other three species. Trap occupancy rates indicate O. nigriplantare polychroma is more common in the tussock habitat, and O. infrapunctatum is more common in the replanted habitat. Few O. zelandicum were found, primarily in the tussock habitat. Pasture areas replanted 13 years ago (now scrub habitat) support a higher diversity and abundance of skinks. Forest areas remain depauperate of skinks. Skink preference for replanted areas suggests that, for now, revegetation benefits their populations, possibly due to greater food sources, lower predation pressure and a wider thermal range.<br><br>Body condition (log weight/ log snout-vent length) and proportion of tail loss of skinks were similar in the different habitat types. However, both O. nigriplantare polychroma and O.lineoocellatum had higher body condition in the replanted than the tussock habitat. Juvenile skinks had significantly lower body condition and a lower proportion of tail loss. Skink body condition was not negatively affected by revegetation or by different habitats, despite the large differences between the habitats. Revegetation currently benefits skink populations. Maintaining a mosaic of habitat types is recommended, because, should revegetation create more forest habitat through plantations or plant succession, it is likely that the population of all four species of skink will decline.<br>


2013 ◽  
Vol 19 ◽  
pp. 157-174 ◽  
Author(s):  
Ellen D. Currano

Leaf-compression fossils with insect feeding traces are unique in providing rich, direct evidence of two levels in a fossil food web. Plant-insect associations dominate terrestrial trophic interactions, emphasizing the need to understand their ecological and evolutionary history. This paper first discusses methods of recognizing insect herbivore damage on fossil leaves and quantifying fossil insect herbivory. By conducting an unbiased insect damage census, damage frequency (percent of leaves with insect feeding damage), percent of leaf surface area removed by insects, and damage diversity (the number of discrete damage morphotypes, or DTs, found on a fossil flora or individual host plant) can all be measured. Three examples of responses of past plant-insect trophic interactions to environmental stresses are examined. In the first case study, late Oligocene fossil floras from Ethiopia document forest response to local perturbation and key characteristics to recognize disturbance in the plant fossil record. The second case study considers the terrestrial ecosystem response to the catastrophic global perturbation at the Cretaceous–Paleogene boundary. In the third case study, the impact of past global warming events—including the Paleocene–Eocene Thermal Maximum—on insect herbivory is discussed. Productive avenues for further research include: insect damage studies conducted outside the North American Cretaceous and Paleogene, actualistic and taphonomic studies of insect herbivory, and tighter collaboration across paleobotany, paleoentomology, botany, and entomology.


2020 ◽  
Vol 11 ◽  
Author(s):  
Karelle Rheault ◽  
Denis Lachance ◽  
Marie-Josée Morency ◽  
Évelyne Thiffault ◽  
Marie Guittonny ◽  
...  

Abandoned unrestored mines are an important environmental concern as they typically remain unvegetated for decades, exposing vast amounts of mine waste to erosion. Several factors limit the revegetation of these sites, including extreme abiotic and unfavorable biotic conditions. However, some pioneer tree species having high levels of genetic diversity, such as balsam poplar (Populus balsamifera), can naturally colonize these sites and initiate plant succession. This suggests that some tree genotypes are likely more suited for acclimation to the conditions of mine wastes. In this study, we selected two contrasting mine waste storage facilities (waste rock from a gold mine and tailings from a molybdenum mine) from the Abitibi region of Quebec (Canada), on which poplars were found to have grown naturally. First, we assessed in situ the impact of vegetation presence on each mine waste type. The presence of balsam poplars improved soil health locally by modifying the physicochemical properties (e.g., higher nutrient content and pH) of the mine wastes and causing an important shift in their bacterial and fungal community compositions, going from lithotrophic communities that dominate mine waste environments to heterotrophic communities involved in nutrient cycling. Next, in a greenhouse experiment we assessed the impact of plant genotype when grown in these mine wastes. Ten genotypes of P. balsamifera were collected locally, found growing either at the mine sites or in the surrounding natural forest. Tree growth was monitored over two growing seasons, after which the effects of genotype-by-environment interactions were assessed by measuring the physicochemical properties of the substrates and the changes in microbial community assembly. Although substrate type was identified as the main driver of rhizosphere microbiome diversity and community structure, a significant effect due to tree genotype was also detected, particularly for bacterial communities. Plant genotype also influenced aboveground tree growth and the physicochemical properties of the substrates. These results highlight the influence of balsam poplar genotype on the soil environment and the potential importance of tree genotype selection in the context of mine waste revegetation.


PLoS ONE ◽  
2008 ◽  
Vol 3 (4) ◽  
pp. e2068 ◽  
Author(s):  
Jules Beekwilder ◽  
Wessel van Leeuwen ◽  
Nicole M. van Dam ◽  
Monica Bertossi ◽  
Valentina Grandi ◽  
...  

2018 ◽  
Vol 5 (3) ◽  
pp. 171991 ◽  
Author(s):  
Sandra R. Schachat ◽  
Conrad C. Labandeira ◽  
S. Augusta Maccracken

Sampling standardization has not been fully addressed for the study of insect herbivory in the fossil record. The effects of sampling within a single locality were explored almost a decade ago, but the importance of sampling standardization for comparisons of herbivory across space and time has not yet been evaluated. Here, we present a case study from the Permian in which we evaluate the impact of sampling standardization on comparisons of insect herbivory from two localities that are similar in age and floral composition. Comparisons of insect damage type (DT) diversity change dramatically when the number of leaves examined is standardized by surface area. This finding suggests that surface area should always be taken into account for comparisons of DT diversity. In addition, the three most common metrics of herbivory—DT diversity, proportion of leaves herbivorized and proportion of leaf surface area herbivorized—are inherently decoupled from each other. The decoupling of the diversity and intensity of insect herbivory necessitates a reinterpretation of published data because they had been conflated in previous studies. Future studies should examine the divergent ecological factors that underlie these metrics. We conclude with suggestions to guide the sampling and analysis of herbivorized leaves in the fossil record.


2020 ◽  
Vol 32 (2) ◽  
pp. 26-31
Author(s):  
Nada AL-Ghaban ◽  
Ghazwan Jasem

Background: Red clover oil (Trifolium pratense) has isoflavones bunches which have estrogen-like exercises and may establish an option in contrast to hormone substitution treatment. The present study investigated the impact of Red clover oil on bone healing in rats by histomorphometric study. Materials and Methods: Intra bony defect was performed in right femur of thirty six healthy male albino rats. Then these rats were randomly divided into three groups (12 rats each): one control and 2 experimental groups. For control, the bony defect was left for normal healing; for the experimental (S) group, the defect was treated with hemostatic absorbable gelatin sponge; and for experimental (RS) group, the bony defect was treated with 0.2 ml red clover oil and covered by haemostatic absorbable gelatin sponge. Six rats from each group were sacrificed at 2 and 4 weeks intervals. Histomorphometric analysis was performed on H&E bone section of all the studied groups which includes counting of bone cells (osteoblasts, osteocytes and osteoclasts), trabecular number, trabecular area and bone marrow space area. Results: Histomorphometric results of bone cells revealed that the combination group stimulated larger numbers of osteoblasts and osteocytes than in sponge and control group. Number of new bone trabeculae, trabecular area and bone marrow space area showed higher mean values in combination groups than others. Highly significant differences between groups were observed in all histomorphometric parameters throughout all durations. Conclusion: Red clover oil stimulated larger numbers of osteoblasts and osteoclasts, indicating increased bone remodeling especially at 2 weeks interval as compared with sponge and control groups. Key words: Bone defect, Red clover, Rats.


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