Abstrakt
Background and aims Marcescence, the phenomenon in which plants hold their leaves after senescence, is common in nature. To date, the ecological relevance of marcescent leaves has been highlighted predominantly in arid ecosystems, where the photodegradation of recalcitrant compounds in such leaves facilitates their subsequent decomposition once shed.
Marcescence, however, is widespread also in temperate ecosystems, where photodegradation is expected to be less pronounced, while other factors such as leaching or limited access of decomposers may be more important. Methods To provide insights into the impact of marcescence on leaf chemistry and potential consequences for decomposition and nutrient cycling in temperate ecosystems, we collected marcescent and shed senescent leaves of the tree genera Quercus L. and Fagus L. throughout two consecutive dormant seasons.
We analysed these leaves for carbon and nitrogen, extracted lignin and water-extractable organic matter, and performed Fourier-transform infrared spectroscopic analyses. Results Our results indicate that marcescent leaves were richer in nitrogen, perhaps, due to a dominance of abiotic processes acting on these leaves (e.g., leaching of carbon), and had decreased lignin contents, likely due to photodegradation, which could subsequently release easily utilisable compounds via breakdown of lignocellulose complexes.
Conclusion Marcescent leaves may be more bioavailable as compared to leaves directly shed after senescence, with potential consequences for nutrient and carbon cycling in temperate ecosystems.