Research Summary• We tested whether the degree of shade-induced plasticity in petiole length and leaf area is related to the mean trait value expressed under high-light conditions, and to what extent trait values expressed under high-light and shaded conditions affect plant performance.• Thirty-four Trifolium repens genotypes were used with a wide range of petiole lengths and leaf areas. Plants were subjected to a high-light environment and two shading regimes: homogeneous shading and a vertical light gradient.• Absolute petiole elongation in response to both shading treatments and absolute leaf area expansion in response to homogeneous shading were independent of the trait values expressed in high light. Consequently, relative plasticity was higher for genotypes with lower high-light trait values. Plasticity was associated with enhanced plant performance in a vertical light gradient but not in homogeneously shaded conditions. We also found costs associated with the ability to express plasticity.• Our results suggest that selection can act separately on trait values expressed under high-light conditions and on the degree of plasticity.
Abstract1. In recent years, belowground plant ecology has experienced a booming interest.This has resulted in major advances towards a greater understanding of belowground plant and ecosystem functioning focused on fine roots, mycorrhizal associations and nutrient acquisition.2. Despite this, other important functions (e.g., on-spot persistence, space occupancy, resprouting after biomass removal) exerted by different belowground plant organs (e.g., roots, rhizomes, bulbs) remain largely unexplored.3. Here, we propose a framework providing a comprehensive perspective on the entire set of belowground plant organs and functions. We suggest a compartment-based approach. We identify two major belowground compartments, that is, acquisitive and nonacquisitive, associated with biomass allocation into these functions. Also, we recommend the nonacquisitive compartment to be divided into structural (e.g., functional roles carried out by rhizomes, such as sharing of resources, space occupancy) and nonstructural (e.g., functional roles exerted by carbohydrates reserve affecting resprouting ability, protection against climate adversity) subcompartments. We discuss methodological challenges-and their possible solutions-posed by changes in biomass allocation across growth forms and ontogenetic stages, and in relation to biomass partitioning and turnover. 4. We urge the implementation of methods and approaches considering all the belowground plant compartments. This way, we would make sure that key, yet lessstudied functions would be incorporated into the belowground plant ecology research agenda. The framework has potential to advance the understanding of belowground plant and ecosystem functioning by considering relations and tradeoffs between different plant functions and organs. At last, we identify four major areas where using the proposed compartment-based approach would be particularly important, namely (a) biomass scaling, (b) clonality-resource acquisition relations, (c) linkages between resprouting and changing environmental conditions and (d) carbon sequestration. K E Y W O R D Sacquisitive and nonacquisitive compartments, belowground plant functions, biomass allocation and turnover, buds and carbohydrates storage, growth forms, ontogeny, rhizomes, roots
Aim To evaluate the relative role of environmental factors and geographical position (latitude and longitude) in determining species distribution and composition of local assemblages of butterflies and birds.Location Czech Republic, central Europe.Methods Canonical correspondence analysis that ordinates species and samples (grid cells in distribution atlases) such that interspecific and intersample differences attributable to environmental factors are maximized. The technique allowed us to test the significance of individual factors, including the geographical ones, by controlling the other factors and accounting for spatial autocorrelation.Results Altitude and climate (temperature and precipitation) accounted for most variance in the interspecific differences in distribution of both butterflies and birds. The distribution of birds was also strongly affected by the area of water bodies, and less strongly, but still significantly, by the area of meadows and mountain open habitats. Habitat types important for the differences in butterfly distribution were deciduous forests, meadows, swamps and mountain open habitats. Some less common habitat types were important only because of the presence of rare species. Latitude and longitude invariably accounted for a large proportion of total variance, and their effect was highly significant even after controlling for the effect of all other environmental factors.Main conclusions Although environmental factors, especially those related to elevation and climate, represent the main determinants of species distribution and composition of local assemblages, the geographical position is very important on this scale of resolution. Understanding distribution patterns, thus, must include not only an understanding of species ecological requirements, but also an understanding of geographical context, which affects structure and dynamics of speciesÕ geographical ranges.
Pain is an important and distressing symptom in Parkinson’s disease (PD). Our aim was to determine the prevalence of pain, its various types and characteristics, as well as its impact on depression and quality of life (QoL) in patients with PD. How pain differs in early- and advanced-stage PD and male and female PD patients was of special interest. One hundred PD patients on dopaminergic medications had a neurological examination and participated in a structured interview on pain characteristics and completed standardized questionnaires. A total of 76% of the patients had pain. The following types of pain were present: musculoskeletal pain accounted for 41% of the total pain, dystonic pain for 17%, central neuropathic pain for 22%, radicular pain for 27%, and other pains (non-radicular low back pain, arthritic, and visceral pain) made up 24%. One type of pain affected 29% of all the subjects, two types 35%, three types 10%, and four types of pain were reported by 2%. All types of pain were more prevalent in advanced-stage PD subjects than in early-stage PD subjects, except for arthritic pain (subclassified under”other pain”). The frequency and intensity of actual, average, and worst experienced pain were significantly more severe in advanced-stage subjects. PD subjects with general pain and in advanced stages were more depressed and had poorer QoL. Depression correlated with worst pain in the last 24 hours and with pain periodicity (the worst depression score in patients with constant pain). QoL correlated with average pain in the last 7 days. Pain is a frequent problem in PD patients, and it worsens during the course of the disease.
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