scholarly journals Light and sex interplay: Differential herbivore damage in sun and shade in dioecious Mercurialis perennis

2018 ◽  
Vol 70 (3) ◽  
pp. 469-479 ◽  
Author(s):  
Sara Selakovic ◽  
Nemanja Stanisavljevic ◽  
Vukica Vujic ◽  
Luka Rubinjoni ◽  
Zivko Jovanovic ◽  
...  

Interactions between plants and herbivorous insects can be shaped by light environment, resulting in differential herbivory in sun and shade. In dioecious species, the combination of plant sex and light-induced changes in defense traits and nutritive value can alter the patterns of foliar damage. We explored the combined effects of light environment and plant sex on natural herbivore damage and plant traits in the dioecious understory forb Mercurialis perennis on Mt. Kopaonik (Serbia). The role of plant traits in predicting the extent of damage was examined as well. Male and female plants from contrasting light environments (shade vs. sun) were analyzed with respect to leaf damage, as well as plant morphological and biochemical traits (size, specific leaf area, carbon-based defensive compounds and nutritional quality). We found prominent differences in herbivore damage between sun and shade conditions, but not between the sexes. Plants from the sun-exposed site had a significantly larger leaf area removed. The specific leaf area co-varied with herbivore damage in an inverse fashion, while leaf nutritional value had a moderate effect. Contrasting light conditions influenced the patterns of intersexual differences in the contents of condensed tannins and soluble proteins, with females exhibiting higher trait values. We found that factors defining risk of consumption were related to plant morphological traits and nutritive value rather than to chemical defenses.

2016 ◽  
pp. 99-103
Author(s):  
Árpád Szalacsi ◽  
Gergely Király ◽  
Szilvia Veres

Specific leaf area (SLA) of English oak (Quercus robur L.) and hornbeam (Carpinus betulus L.) as members of Querco robori-Carpinetum were investigated in two different habitat in terms of gap forest management: in the gap and in the inert forest. The artificial opening process of the forest resulted in more light for growing saplings and need for acclimatization. Photosynthesis is one of the most important ways for plant life and plant production basically influenced by altered light condition resulted in opening process. Efficient photosynthesis is important for plant life, plant production, but species-dependent plasticity of photosynthesis makes one species more tolerant, than others. The specific leaf area is acceptable parameters for characterising plant production, dry matter content and leaf structure. The dry matter content based on known leaf area is higher in oak both sun and shade leaves, than hornbeam. The different place of leaves in the canopy of trees did not influence the values of SLA.


2008 ◽  
Vol 68 (3) ◽  
pp. 553-559 ◽  
Author(s):  
AVF. Jardim ◽  
MA. Batalha

Although there have been advances in methods for extracting information about dispersal processes, it is still very difficult to measure them. Predicting dispersal groups using single readily-measured traits would facilitate the emergence of instructive comparisons among ecological strategies of plants and offer a path towards improved synthesis across field experiments. The leaf-height-seed scheme consists of three functional traits: specific leaf area, plant canopy height, and seed mass. We tested, applying logistic regression analysis, whether these traits are potential predictors of dispersal guilds in a disjoint cerrado woodland site in southeastern Brazil. According to our results, none of the plant traits studied could predict dispersal guild; this means that abiotically and biotically dispersed species showed similar values of specific leaf area, height, and seed mass. The species of both guilds exhibited sclerophylly, probably a result of the typical soil nutrient deficiency of cerrado, which also may have placed constraints upon plant canopy height regardless of the dispersal mode. In the cerrado, some abiotically dispersed trees might present higher than expected seed mass as support to the investment in high root-to-shoot ratio at the seedling stage. Seeds of bird-dispersed species are limited in size and mass because of the small size of most frugivorous birds. Since soil nutrient quality might contribute to the similarity between the dispersal guilds regarding the three traits of the scheme, other plant traits (e.g., root depth distribution and nutrient uptake strategy) that detail the former should be considered in future predictive studies.


Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 865
Author(s):  
Zuzana Münzbergová ◽  
Jiří Skuhrovec

Data on plant herbivore damage as well as on herbivore performance have been previously used to identify key plant traits driving plant–herbivore interactions. The extent to which the two approaches lead to similar conclusions remains to be explored. We determined the effect of a free-living leaf-chewing generalist caterpillar, Spodoptera littoralis (Lepidoptera: Noctuidae), on leaf damage of 24 closely related plant species from the Carduoideae subfamily and the effect of these plant species on caterpillar growth. We used a wide range of physical defense leaf traits and leaf nutrient contents as the plant traits. Herbivore performance and leaf damage were affected by similar plant traits. Traits related to higher caterpillar mortality (higher leaf dissection, number, length and toughness of spines and lower trichome density) also led to higher leaf damage. This fits with the fact that each caterpillar was feeding on a single plant and, thus, had to consume more biomass of the less suitable plants to obtain the same amount of nutrients. The key plant traits driving plant–herbivore interactions identified based on data on herbivore performance largely corresponded to the traits identified as important based on data on leaf damage. This suggests that both types of data may be used to identify the key plant traits determining plant–herbivore interactions. It is, however, important to carefully distinguish whether the data on leaf damage were obtained in the field or in a controlled feeding experiment, as the patterns expected in the two environments may go in opposite directions.


2003 ◽  
Vol 81 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Gunnar Austrheim ◽  
Ove Eriksson

Recruitment is critical for the maintenance of plant populations and community diversity, but sexual regeneration is considered to be infrequent in climatically harsh habitats such as subalpine grasslands. This study examines the importance of regeneration through seed for 16 sparse herb species, and we asked whether their populations are limited by safe sites or the availability of seeds. Seedling recruitment and winter survival were recorded after sowing in an experimental split-plot design in (i) pasture grazed by livestock, and (ii) exclosed grassland cultivated for annual mowing. In addition we examined the effect of disturbance and local seedbank recruitment. All species were able to recruit and survive the first winter in at least some of the experimental plots, although none were initially present. Recruitment mainly occurred in disturbed plots, and disturbed pasture plots had a significantly higher recruitment than disturbed exclosures for all species except Silene dioica. We further examined whether specific plant traits were related to variation in recruitment. Lower recruitment in the disturbed exclosure was associated with higher specific leaf area, leaf dry weight, and seed number. In contrast, seeds sown in disturbed pasture recruited more independently of species traits. The exception was a negative correlation between recruitment and leaf dry weight, and an unexpected negative correlation with seed weight. We suggest that recruitment differences among habitats mainly reflect lower humidity in the exclosure. Consequently, small stature plants with small specific leaf area should have the highest recruiting probability when exposed to drought. The almost exclusive recruitment on disturbed plots indicates a strong competitive effect on the target species in vegetated plots, and suggests that safe sites for regeneration through seed are rare in subalpine grasslands.Key words: colonization, herbs, plant abundance and distribution, disturbance, pastures, cultivated exclosures, sowing experiment.


2008 ◽  
Vol 59 (2) ◽  
pp. 149 ◽  
Author(s):  
B. Salter ◽  
G. D. Bonnett ◽  
R. J. Lawn

Sugarcane suckers are tillers that appear late in crop development. They dilute the sucrose content of the harvested cane at the mill, reducing grower profitability. Suckers appear to have different morphology from other sugarcane stalks. Experiments were established to quantify some of these morphological differences, to determine whether these differences were conserved across a vegetatively propagated generation, and to investigate the influence of the mature stalk to which the sucker is attached on sucker morphology. Experiments were established in northern Queensland, Australia, using cvv. Q117, Q138, and Q152 to compare suckers with young primary stalks in a plant crop and/or young ratoon stalks. Leaf lamina length, breadth, area, height to last fully expanded leaf, internode diameter, and growth measurements were taken. Suckers had broader leaves, resulting in a smaller leaf length/breadth ratio, longer leaf sheaths, and lower specific leaf area at least for the first 3 leaves. Sucker stalks were thicker than normal stalks. Sucker growth was highly variable, but some were able to outgrow young primary stalks in a plant crop. When mature stalks, to which suckers were attached, were removed, the leaves produced by suckers were more similar to leaves on normal stalks with larger length/breadth ratio. The morphological differences were not carried over into plants arising from the buds on suckers. Although the reasons for these morphological differences are unknown, it is likely that the transfer of some factor(s) from the stalks to which suckers are attached, and/or an altered light environment within the canopy, may contribute to the morphology of sucker shoots.


Biology ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 250
Author(s):  
Stefania Toscano ◽  
Ferdinando Branca ◽  
Daniela Romano ◽  
Antonio Ferrante

In the context of seaside landscaping, one of the greatest challenges for practitioners and scientists is to select suitable species that are able to tolerate salt spray. This is the key aspect for a wide number of potentially suitable species. The objectives of this study were (1) to identify plant traits associated with species tolerance to salt stress and (2) to evaluate the responses of different shrub species to salt spray. For this purpose, a study was conducted to determine the effects of salt spray on twenty-four ornamental shrubs using rapid and easy-to-use methodology. The species were subjected twice a week to nebulization treatment with simulated seawater solution for 60 days. Every 20 days, net photosynthesis, stomatal conductance, transpiration rate, and chlorophyll a fluorescence were determined. Furthermore, dry biomass of the different organographic portions, leaf number, leaf area, Specific Leaf Area, chlorophyll content, and leaf damage were determined at the end of the experiment. The species exposed to seawater solution showed different physiological and morphological responses. Based on the above indices, these ornamental shrubs were screened and categorized as tolerant, moderately tolerant, or susceptible. The results suggest that Convolvulus, Ceratonia, and Ligustrum are more tolerant to salt spray than numerous other genotypes; L. langmaniae, Cascabela, and L. frutescens, conversely, are more sensitive. Among the plant traits, the morphological parameters thoroughly characterized the effects of the salt spray, but they were destructive, with the only exception being the leaf damage percentage. This last non-destructive parameter is interesting considering the aesthetic value that ornamental plants must have. The physiological parameters, and in particular photosynthesis activity, can instead be used as a non-destructive screening method to select species suitable for ornamental green spaces near the sea.


1996 ◽  
Vol 351 (1345) ◽  
pp. 1309-1318 ◽  

Seed mass is correlated with a number of other plant traits, including dispersal mode, growth form and specific leaf area. Specific leaf area is the main determinant of potential relative growth rate and an indicator of the site quality to which a species is adapted. The relationships with dispersal mode and growth form have consistent form in five datasets from three continents, and each account for about 20-30 % of variation in log seed mass. Thus, there is also very substantial variation within growth form and dispersal categories. Much, but not all, of the 20-30% is associated with shifted family composition between growth forms or dispersal modes. Experiments have shown that seedlings of larger-seeded species are better able to survive hazards including deep shade, drought, physical damage and the presence of competing vegetation. If there is a common mechanism under these different hazards, it seemingly must be a ‘reserve effect’, whereby during deployment and early growth larger-seeded species hold a bigger percentage of seed reserves uncommitted to seedling structure and available to support respiration or repair damage. A reserve effect has not yet been demonstrated directly. It remains possible that different mechanisms operate under different hazards. Under a reserve effect, advantages of larger seed size should be temporary, and temporary advantage has indeed been observed with regard to seedling survival under dense shade. Although larger seed mass confers benefits on seedlings, larger seeds must necessarily be produced in smaller numbers per unit of resource allocated. Seed mass is presumed to have evolved as a compromise between these counterposed pressures. Yet there has proved to be surprisingly little difference in average seed mass between very different vegetation regions, at least in temperate climates. Rather, there is startlingly wide variation in seed mass among species growing interspersed with each other. Recent applications of game theory may be capable of accounting for this wide variation between coexisting species, but at present these models are driven by competition among seedling species (as opposed to between seedlings and adults). It remains unclear whether competition among seedlings is a decisive influence on species composition in most of the world’s vegetation types.


Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 49
Author(s):  
Piotr Salachna ◽  
Rafał Piechocki

Hardy ferns form a group of attractive garden perennials with an unknown response to abiotic stresses. The aim of this study was to evaluate the tolerance of three species of ferns of Dryopteris genus (D. affinis, D. atrata and D. filix-mas) and one cultivar (D. filix-mas cv. “Linearis-Polydactylon”) to salinity and light stress. The plants were grown in full sun and shade and watered with 50 and 100 mM dm−3 NaCl solution. All taxa treated with 100 mM NaCl responded with reduced height, leaf greenness index and fresh weight of the above-ground part. In D. affinis and D. atrata salinity caused leaf damage manifested by necrotic spots, which was not observed in the other two taxa. The effect of NaCl depended on light treatments and individual taxon. D. affinis and D. atrata were more tolerant to salinity when growing under shade. Contrary to that, D. filix-mas cv. “Linearis-Polydactylon” seemed to show significantly greater tolerance to this stress under full sun. Salt-treated D. filix-mas cv. “Linearis-Polydactylon” plants accumulated enhanced amounts of K+ in the leaves, which might be associated with the taxon’s tolerance to salinity. Among the investigated genotypes, D. filix-mas cv. “Linearis-Polydactylon” seemed the most and D. affinis and D. atrata the least tolerant to salinity and light stress.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jorge Palomo-Kumul ◽  
Mirna Valdez-Hernández ◽  
Gerald A. Islebe ◽  
Manuel J. Cach-Pérez ◽  
José Luis Andrade

AbstractWe evaluated the effect of ENSO 2015/16 on the water relations of eight tree species in seasonally dry tropical forests of the Yucatan Peninsula, Mexico. The functional traits: wood density, relative water content in wood, xylem water potential and specific leaf area were recorded during the rainy season and compared in three consecutive years: 2015 (pre-ENSO conditions), 2016 (ENSO conditions) and 2017 (post-ENSO conditions). We analyzed tree size on the capacity to respond to water deficit, considering young and mature trees, and if this response is distinctive in species with different leaf patterns in seasonally dry tropical forests distributed along a precipitation gradient (700–1200 mm year−1). These traits showed a strong decrease in all species in response to water stress in 2016, mainly in the driest site. Deciduous species had lower wood density, higher predawn water potential and higher specific leaf area than evergreen species. In all cases, mature trees were more tolerant to drought. In the driest site, there was a significant reduction in water status, regardless of their leaf phenology, indicating that seasonally dry tropical forests are highly vulnerable to ENSO. Vulnerability of deciduous species is intensified in the driest areas and in the youngest trees.


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