Decomposition of Fine Roots and Aboveground Agroforestry Litter as Plant-soil Feedback After Volcanic Ash Deposition

Abstract

Background and PurposeAbove- and belowground organic inputs feed decomposer communities in the soil enhancing soil organic matter (Corg) formation, depending on the vegetation, soil, contextual factors and human management of (agro)ecosystems. Plant-soil feedback in volcanic ash rapidly increases Corg during transformation to Andisols. We quantified fine root turnover in agroforestry systems, including the ash-adapted native tree Parasponia rigida, as part of the C accumulation process. MethodsFine root (<2 mm) decomposition was quantified with a total of 1440 litterbag samples, testing the effects of six tree species (Coffea canephora, Persea americana, Durio zibethinus, Gliricidia sepium, Falcataria moluccana and Parasponia rigida), three distances to the nearest coffee trees, two seasons (rainy and dry), two sites (with and without recent ash deposits), four time intervals (2, 4, 6 and 8 weeks) and five replicates. Soil temperature around the litterbags was used to derive equivalent decomposition rates at 20oC. The ratio of lignin plus phenolics over nitrogen was used as main litter quality indicator.ResultsDecomposition of fine tree roots was up to three times faster than that of aboveground litter with the same quality index measured in the same habitat. Root decomposition was slower in topsoils with recent volcanic ash, with a mean residence time extended by, on average, two weeks. Decomposition of roots of the ash-adapted native tree Parasponia rigida was especially rapid. ConclusionsFine root turnover contributes to the Corg accumulation that turns low-C volcanic ash into high-carbon andic soil and has relatively short necromass residence times.

Pengaruh Education First Aid (E-Fa) Game terhadap Pengetahuan Layperson Pertolongan Pertama Cedera Pada Anak Usia Sekolah

“…Cedera merupakan kondisi yang diakibatkan beragam factor baik internal maupun eksternal yang menimbulkan kerusakan pada jaringan tubuh (Association et al, 2017;International Federation of Red Cross and Red Crescent Societies, 2020;Sari & Purnamasari, 2021). Prevalensi cedera di Indonesia menunjukkan peningkatan dilihat dari angka kejadian sejak tahun 2008 menunjukkan angka 7,5%, selanjutnya tahun 2013 sebesar 8,2% dan data terakhir tahun 2018 menunjukkan angka kejadian sebesar 9,2%.…”

“…Angka prevalensi cedera yang ditemukan pada anak di usia < 14 tahun di Indonesia mengalami peningkatan mencapai angka 12,1% dalam lima tahun terakhir. Cedera tertinggi ditemukan di lingkungan sekolah (18,5%), hal ini berhubungan dengan kurang aman dan anak sekolah yang sangat ingin tahu namun dengan pemahaman yang belum cukup berkaitan tentang konsep bahaya serta kemampuan pertolongan pertama yang masih kurang (RISKESDAS, 2018;Sari & Purnamasari, 2021;Usman et al, 2021). Dalam pemecahan masalah, prinsip pertama berkaitan dengan informasi yang disediakan dalam bentuk game seringkali tepat pada waktunya untuk digunakan oleh pemain atau sesuai permintaan sehingga pemain dapat memanfaatkannya sesuai kebutuhan (Arum et al, 2021;Boeker et al, 2013;Charlier & De Fraine, 2013;Deynilisa et al, 2022).…”