spannede Pflanzenstudien

[Herr von Böde]

Es gibt immer mal wieder interessante Studien und Forschungsergebnisse aus dem Bereich der Botanik.
Da ich dafür keinen passenden Faden gefunden habe, hier also eine Möglichkeit soetwas zu verlinken.

[Herr von Böde]

Journal of Ecology - Bridging ecology and physics: Australian fairy circles regenerate following model assumptions on ecohydrological feedbacks

Abstract

So‐called fairy circles (FCs) comprise a spatially periodic gap pattern in arid grasslands of Namibia and north‐west Western Australia. This pattern has been explained with scale‐dependent ecohydrological feedbacks and the reaction‐diffusion, or Turing mechanism, used in process‐based models that are rooted in physics and pattern‐formation theory. However, a detailed ecological test of the validity of the modelled processes is still lacking.
Here, we test in a spinifex‐grassland ecosystem of Western Australia the presence of spatial feedbacks at multiple scales. Drone‐based multispectral analysis and spatially explicit statistics were used to test if grass vitality within five 1‐ha plots depends on the pattern of FCs that are thought to be a critical extra source of water for the surrounding matrix vegetation. We then examined if high‐ and low‐vitality grasses show scale‐dependent feedbacks being indicative of facilitation or competition. Additionally, we assessed facilitation of grass plants for different successional stages after fire at fine scales in 1‐m2 quadrats. Finally, we placed soil moisture sensors under bare soil inside the FC gap and under plants at increasing distances from the FC to test if there is evidence for the ‘infiltration feedback’ as used in theoretical modelling.
We found that high‐vitality grasses were systematically more strongly associated with FCs than low‐vitality grasses. High‐vitality grasses also had highly aggregated patterns at short scales being evidence of positive feedbacks while negative feedbacks occurred at larger scales. Within 1‐m2 quadrats, grass cover and mutual facilitation of plants was greater near the FC edge than further away in the matrix. Soil moisture after rainfall was lowest inside the FC with its weathered surface crust but highest under grass at the gap edge, and then declined towards the matrix, which confirms the infiltration feedback.
Synthesis. The study shows that FCs are a critical extra source of water for the dryland vegetation, as predicted by theoretical modelling. The grasses act as ‘ecosystem engineers’ that modify their hostile, abiotic environment, leading to vegetation self‐organization. Overall, our ecological findings highlight the validity of the scale‐dependent feedbacks that are central to explain this emergent grassland pattern via the reaction‐diffusion or Turing‐instability mechanism.

(...)

[Arkan]

Böde ist wieder da.

[Herr von Böde]

Böde ist wieder da.

Wildkraut vergeht nicht


nature plants "Calcium dynamics during trap closure visualized in transgenic Venus flytrap"

Abstract

The leaves of the carnivorous plant Venus flytrap, Dionaea muscipula (Dionaea) close rapidly to capture insect prey. The closure response usually requires two successive mechanical stimuli to sensory hairs on the leaf blade within approximately 30 s (refs. 1,2,3,4). An unknown biological system in Dionaea is thought to memorize the first stimulus and transduce the signal from the sensory hair to the leaf blade2. Here, we link signal memory to calcium dynamics using transgenic Dionaea expressing a Ca2+ sensor. Stimulation of a sensory hair caused an increase in cytosolic Ca2+ concentration ([Ca2+]cyt) starting in the sensory hair and spreading to the leaf blade. A second stimulus increased [Ca2+]cyt to an even higher level, meeting a threshold that is correlated to the leaf blade closure. Because [Ca2+]cyt gradually decreased after the first stimulus, the [Ca2+]cyt increase induced by the second stimulus was insufficient to meet the putative threshold for movement after about 30 s. The Ca2+ wave triggered by mechanical stimulation moved an order of magnitude faster than that induced by wounding in petioles of Arabidopsis thaliana5 and Dionaea. The capacity for rapid movement has evolved repeatedly in flowering plants. This study opens a path to investigate the role of Ca2+ in plant movement mechanisms and their evolution.
(...)

[אל תשאלו]

nn0c04298_si_001.pdf

Supporting Information for Highly Elastic Hydrated Cellulosic Materials with Durable Compressibility and Tunable Conductivity

Anisotropic cellular materials with direction-dependent structure and durable mechanical properties enable various applications (e.g., nanofluidics, biomedical devices, tissue engineering, and water purification), but their widespread use is often hindered by complex and scale-limited fabrication and unsatisfactory mechanical performance. Here, inspired by the anisotropic and hierarchical material structure of tendons, we demonstrate a facile, scalable top-down approach for fabricating a highly elastic, ionically conductive, anisotropic cellulosic material (named elastic wood) directly from natural wood via chemical treatment. The resulting elastic wood demonstrates good elasticity and durable compressibility, showing no sign of fatigue after 10 000 compression cycles. The chemical treatment not only softens the wood cell walls by partially removing lignin and hemicellulose but introduces an interconnected cellulose fibril network into the wood channels. Atomistic and continuum modeling further reveals that the absorbed water can freely and reversibly move inside the elastic wood and therefore helps the elastic wood accommodate large compressive deformation and recover to its original shape upon compression release. In addition, the elastic wood showed a high ionic conductivity of up to 0.5 mS cm–1 at a low KCl concentration of 10–4 M, which can be tuned by changing the compression ratio of the material. The demonstrated elastic, mechanically robust, and ionically conductive cellulosic material combining inherited anisotropic cellular structure from natural wood and a self-formed internal gel may find a variety of potential applications in ionic nanofluidics, sensors, soft robots, artificial muscle, environmental remediation, and energy storage.

https://pubs.acs.org/doi/suppl/10.1021/ ... si_001.pdf

[אל תשאלו]

A new perspective on transparent wood: Lignin-retaining transparent wood

Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30 wt% of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Meanwhile, lignin removal weakens the wood structure, limiting the fabrication of large structure. Here, a green and industrially feasible method was introduced to prepare transparent wood. Up to 80 wt% of lignin was preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high lignin content transparent wood with transmittance of 83%, haze of 75%, thermal conductivity of 0.23 W/mK, and work-to-fracture of 119.5 J/m3 (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained is positioned for energy saving buildings.

https://www.researchgate.net/publicatio ... arent_wood

[Herr von Böde]

scientific reports - The dynamics of plant nutation

Abstract

In this article we advance a cutting-edge methodology for the study of the dynamics of plant movements of nutation. Our approach, unlike customary kinematic analyses of shape, period, or amplitude, is based on three typical signatures of adaptively controlled processes and motions, as reported in the biological and behavioral dynamics literature: harmonicity, predictability, and complexity. We illustrate the application of a dynamical methodology to the bending movements of shoots of common beans (Phaseolus vulgaris L.) in two conditions: with and without a support to climb onto. The results herewith reported support the hypothesis that patterns of nutation are influenced by the presence of a support to climb in their vicinity. The methodology is in principle applicable to a whole range of plant movements.
(...)

Sekundärquelle, deutsch:
https://www.grenzwissenschaft-aktuell.d ... n20210120/

“Tatsächlich sehen wir hier Signaturen komplexen Verhaltens“, erläutert Calvo- „Der einzige Unterschied zu uns Menschen besteht darin, dass dieses Verhalten nicht auf neuralen Vorgängen basieren kann, (da den Pflanzen hierzu die notwendigen neuralen Nervennetzwerkstrukturen fehlen). Was wir hier aber sehen, ist nicht nur ein reines Anpassungsverhalten. Wir sehen hier ein vorausschauendes, zielgerichtetes und flexibles Verhalten.“