Salt marsh biomechanics

This repository contains the data related to the paper "__Biomechanical traits of salt marsh vegetation are insensitive to future climate scenarios__" in which the biomechanical response of salt marsh plant species to future climate conditions is documented.
Specimens of the European salt marsh species _Spartina anglica_ and _Elymus athericus_ were exposed to enhanced water temperature (+ 3°) and CO2 (800 ppm) levels in a mesocosm experiment for 13 weeks in a full factorial design. Afterwards, biomechanical traits were estimated along the stem at different heights above the soil level using a three-point bending test performed with a universal testing machine (ZwickRoell) using a 5 N load cell. A stamp was lowered onto the centre of the sample, resting on two support bars, with a displacement rate of 10 mm/min until the sample broke or buckled irreversibly to record the breaking force Fmax (N), which the sample can withstand. For _Spartina_, the span width s (mm) between support bars was adjusted to keep a diameter to distance ratio between 1:10 and 1:15 while minimising the number of span width changes during measurements. For _Elymus_ a constant span width of 28 mm was set, which exceeded these limits, but was the minimum realisable span width. The linear part of the recorded force–deflection curve was then used to calculate flexural rigidity J (N mm2). The second moment of area I (mm4) was derived from the stem diameter assuming a hollow tubular cross-section for _Spartina_ and a filled circular cross-section for _Elymus_. The Young’s bending modulus E (N/mm2) was then estimated as the ratio of J and I.
Sample stem or outer diameter do was measured with a digital calliper gauge at four locations per sample and consecutively averaged. Inner diameter di was measured at the sample ends. In cases where the inner diameter could not be measured with the calliper gauge, di = 0.1 mm was assumed.
This study is part of the project sea4soCiety (FKZ: 03F0896), one of the six research consortia of the German Marine Research Alliance (DAM) research mission “Marine carbon sinks in decarbonization pathways” (CDRmare) funded by the Federal Ministry of Education and Research of Germany (BMBF). It was further partially funded by the Lower-Saxon Ministry of Research and Culture and the Volkswagen Stiftung (FKZ: 76251-17-5/19, Gute Küste Niedersachsen) and by The Helmholtz Climate Initiative (HI-CAM). HI-CAM is funded by the Helmholtz Association’s Initiative and Networking Funds (10.13039???/501100009318).