Relations and dependencies between morphological characters

Allometric equations for estimating peak uprooting force of riparian vegetation

Uprooting caused by flood events is a significant disturbance factor that affects the establishment, growth, and mortality of riparian vegetation. If the hydraulic drag force acting on riparian plants exceeds the peak uprooting force originate from their below-ground portion, it may result in the uprooting of these plants. Despite previous studies have documented and investigated the uprooting processes and factors influencing the peak uprooting force of plants, most of these studies have focused on how the root morphological traits of tree and shrub seedlings affect peak uprooting force or mainly collected data in indoor experiments, which may limit the extrapolation of the results to natural environments. To address these limitations, we assume that the peak uprooting force can be estimated by the morphological traits of the above-ground portion of the vegetation. In this study, we conducted in-situ vertical uprooting tests on three locally dominant species: Conyza canadensis, Daucus carota, and Leonurus sibiricus, in a typical riverine environment. The three species were found to have the highest abundance based on the outcomes of the quadrat method. We measured the peak uprooting force, plant height, stem basal diameter, shoot and root wet biomass, and shoot and root dry biomass of each plant and compared them between species. Furthermore, we quantified the influence of morphology on peak uprooting force. Our results showed significant differences in morphological traits and peak uprooting force among the three species. We found a significant positive correlation between peak uprooting force and the morphological traits of the three species. The peak uprooting force increases with plant size following a power law function which is analogous to allometric equations. The allometric equation provided a convenient and non-destructive method to estimate the peak uprooting force based on the above-ground morphological traits of the plants, which may help to overcome the limitations of measuring root morphological traits.

Morphometric Analysis of Coptotermes spp. Soldier Caste (Blattodea: Rhinotermitidae) in Indonesia and Evidence of Coptotermes gestroi Extreme Head-Capsule Shapes

Linear and geometric morphometrics approaches were conducted to analyze the head capsule (HC) shape of collected soldier caste specimens of Coptotermes from various locations in Indonesia. The soldiers' morphology was observed and measured. The results of the principal component analysis of the group of all species showed two important groups of variables, i.e., the body size and setae characteristics of the pronotum and head. The multicollinearity of the morphometric variables showed the importance of body measurements as well as important alternative characteristics such as the pronotum setae (PrS) and HC setae. Four trends of HC shape were observed across the species. Interestingly, three extreme shapes were depicted by geometric morphometrics of the C. gestroi HC. The phylogenetic tree inferred from 12S and 16S mitochondrial gene fragments showed high confidence for C. gestroi populations. The lateral expansion of the posterior part of the HC across the species was in accordance with the increasing of the number of hairlike setae on the pronotum and HC. These differences among species might be associated with mandible-force-related defensive labor and sensitivity to environmental stressors.

Knowledge

We investigate the basic principles of structural knowledge. Structural knowledge underlies cognition, and it organizes, selects and assigns meaning to information. It is the result of evolutionary, cultural and developmental processes. Because of its own constraints, it needs to discover and exploit regularities and thereby achieve a complexity reduction.