scholarly journals Root trait responses to drought depend on plant functional group

2019 ◽  
Author(s):  
Y.M. Lozano ◽  
C.A. Aguilar-Trigueros ◽  
I.C. Flaig ◽  
M.C. Rillig

ABSTRACTDrought can strongly modify plant diversity and ecosystem processes. As droughts are expected to intensify in the future, it is important to better understand plant responses to drought. We expect that roots traits constitute an overlooked but powerful predictor of plant responses as roots are in direct contact with the soil environment, taking up nutrients and water.Here, we determine which root traits are sensitive to drought, the magnitude of that response, whether their predictive power and relationships with shoot biomass are affected by drought and whether all these responses depend on plant functional group. To do so, we conducted a glasshouse experiment with 24 plant species grown in pots (10 replicates per species), which represent three different functional groups: grasses, herbs and legumes. All replicates were well watered during the first month and then half of the replicates were kept under drought (30 % water holding capacity (WHC)) with the other half serving as control (kept at 70% WHC). After two months of the treatment, leaf and root traits were measured.Leaf traits had a strong but more uniform response to drought compared to root traits. Root trait response was variable and differed by plant functional group. Most grasses had increased root diameter, specific root surface area (SRSA) while decreased root tissue density (RTD) with drought. Production of thicker roots with a low tissue density could allow grasses to achieve greater nutrient and water acquisition through mycotrophy and would be linked to an increase in the reserve of non-structural carbohydrates needed for osmoregulation. Herbs had decreased SRSA and specific root length (SRL) while increase root carbon allocation. Reduction of root elongation or sacrifice of fine roots would be compensated by an increase in root carbon allocation, which allow herbs to improve water uptake. Legumes did not alter root morphological traits but promote an early flowering in order to scape drought.Our results identify changes in root morphological traits as mechanisms to likely face drought, a response that is species-specific and differed among functional groups.

Author(s):  
Nathaly Guerrero-Ramirez ◽  
Liesje Mommer ◽  
Grégoire T. Freschet ◽  
Colleen M. Iversen ◽  
M. Luke McCormack ◽  
...  

AbstractMotivationTrait data are fundamental to quantitatively describe plant form and function. Although root traits capture key dimensions related to plant responses to changing environmental conditions and effects on ecosystem processes, they have rarely been included in large-scale comparative studies and global models. For instance, root traits remain absent from nearly all studies that define the global spectrum of plant form and function. Thus, to overcome conceptual and methodological roadblocks preventing a widespread integration of root trait data into large-scale analyses we created the Global Root Trait (GRooT) Database. GRooT provides ready-to-use data by combining the expertise of root ecologists with data mobilization and curation. Specifically, we (i) determined a set of core root traits relevant to the description of plant form and function based on an assessment by experts, (ii) maximized species coverage through data standardization within and among traits, and (iii) implemented data quality checks.Main types of variables containedGRooT contains 114,222 trait records on 38 continuous root traits.Spatial location and grainGlobal coverage with data from arid, continental, polar, temperate, and tropical biomes. Data on root traits derived from experimental studies and field studies.Time period and grainData recorded between 1911 and 2019Major taxa and level of measurementGRooT includes root trait data for which taxonomic information is available. Trait records vary in their taxonomic resolution, with sub-species or varieties being the highest and genera the lowest taxonomic resolution available. It contains information for 184 sub-species or varieties, 6,214 species, 1,967 genera and 254 families. Due to variation in data sources, trait records in the database include both individual observations and mean values.Software formatGRooT includes two csv file. A GitHub repository contains the csv files and a script in R to query the database.


2021 ◽  
Author(s):  
YOUSIF ZAINELABDEEN

Livestock grazing is one of the major human activities that cause a change in plant community structure and composition. We studied the effect of different grazing intensities (light, moderate, heavy, and no grazing) on aboveground biomass, species richness, and plant functional group (PFG) diversity. The light, moderate, heavy, and no grazing treatments correspond to 0.23, 0.46, 0.92, and 0.00 Animal Units ha-1 respectively. A total of 78 species classified into eight PFGs (perennial tall grass, perennial short grass, shrubs, legumes, Liliaceae herb, annual/biennial plant, perennial tall forbs and perennial short forbs) were identified. We found that the total species richness increased under light and moderate grazing intensity. However, the responses of each PFG to grazing differed. As grazing intensity increased, so did the richness of short species (perennial short grass, perennial short grass and legume) in the community. The richness of shrub is unaffected by grazing. With increasing grazing intensity, the aboveground biomass of perennial tall grass and perennial tall forbs decreased significantly, while that of annual/biennial plant functional groups increased. The community diversity and evenness of annual/biennial plants increased significantly with grazing intensity. We concluded that heavy grazing has negative impacts on plant functional group richness and aboveground biomass.


2017 ◽  
pp. 89
Author(s):  
Aura Azócar ◽  
Fermín Rada ◽  
Carlos García-Nuñez

<p>The identification of plant functional groups allows to evaluate plant properties as: recovering capacity, regeneration and resistence to environmental changes. It is possible to define plant functional groups in the seasonal savana and the high barren plateau taking in to account the ecophysiological plant responses to water stress and daily temperature-water rythmn, respectively. In the savana, although the wooden component is constituted by evergreen and deciduous tree species, they make only a functional group taking in to account their responses to water stress, this is similar in the herbaceous component. Results suggest that a change in environmental factors may generate a floristic replace without major changes in the system function.<br />However, in the high barren plateau, the different life forms also constitute different functional groups according to plant responses to temperature-water factor, suggesting that the substitution of any group will put in danger the preservation of this ecosystem.</p>


2021 ◽  
Vol 7 (5) ◽  
pp. 333
Author(s):  
Lourdes Morillas ◽  
Javier Roales ◽  
Cristina Cruz ◽  
Silvana Munzi

Lichens are classified into different functional groups depending on their ecological and physiological response to a given environmental stressor. However, knowledge on lichen response to the synergistic effect of multiple environmental factors is extremely scarce, although vital to get a comprehensive understanding of the effects of global change. We exposed six lichen species belonging to different functional groups to the combined effects of two nitrogen (N) doses and direct sunlight involving both high temperatures and ultraviolet (UV) radiation for 58 days. Irrespective of their functional group, all species showed a homogenous response to N with cumulative, detrimental effects and an inability to recover following sunlight, UV exposure. Moreover, solar radiation made a tolerant species more prone to N pollution’s effects. Our results draw attention to the combined effects of global change and other environmental drivers on canopy defoliation and tree death, with consequences for the protection of ecosystems.


2016 ◽  
Vol 43 (2) ◽  
pp. 105 ◽  
Author(s):  
Lu Wang ◽  
Yong-Ling Ruan

Roots and shoots are distantly located but functionally interdependent. The growth and development of these two organ systems compete for energy and nutrient resource, and yet, they keep a dynamic balance with each other for growth and development. The success of such a relationship depends on efficient root-shoot communication. Aside from the well-known signalling processes mediated by hormones such as auxin and cytokinin, sugars have recently been shown to act as a rapid signal to co-ordinate root and shoot development in response to endogenous and exogenous clues, in parallel to their function as carbon and energy resources for biomass production. New findings from studies on vascular fluids have provided molecular insights into the role of sugars in long-distance communications between shoot and root. In this review, we discussed phloem- and xylem- translocation of sugars and the impacts of sugar allocation and signalling on balancing root–shoot development. Also, we have taken the shoot–root carbon–nitrogen allocation as an example to illustrate the communication between the two organs through multi-layer root–shoot–root signalling circuits, comprising sugar, nitrogen, cytokinin, auxin and vascular small peptide signals.


2021 ◽  
Vol 755 ◽  
pp. 143551
Author(s):  
Juliane Hirte ◽  
Florian Walder ◽  
Julia Hess ◽  
Lucie Büchi ◽  
Tino Colombi ◽  
...  

2021 ◽  
Vol 17 (Especial) ◽  
pp. 19-27
Author(s):  
Nelcy Aguilar Sasari ◽  
Milenka Alessandra Fernández Ledezma ◽  
Tania Araujo-Burgos

Additives are necessary substances to improve the nutritional and organoleptic properties and the shelf life of processed food. In addition, their use is regulated, and it must be declared on the food labels. Thus, the objective of this research was to determine the frequency of food additives in processed baby products in Cochabamba metropolitan area (Bolivia). Data were collected by label reading and a frequency analysis was performed by additives and by functional group. 26 baby products were found where 41 food additives were identified with an occurrence of 256 times, and a mean of 9,8 additives per product. Moreover, the functional groups most widely used are antioxidants and colorants. Finally, the most frequent additives are mostly harmless, except for sodium nitrate and copper sulfate.


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