2026-10-14T05:13:12Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34027398 2026-09-29T23:40:21Z category_26998 portal_12 item_type_5 month_year_09_2026

Siqi Yang: Effect of Season and Health Status on Nutrient Dynamics in Diseased Agathis Australis Forests Siqi Yang (11773766) Other environmental sciences not elsewhere classified Kauri dieback Phytophthora agathidicida soil nutrient supply seasonal variation nutrient dynamics <table><tr><td><p dir="ltr">Kauri (Agathis australis), an endemic conifer, is threatened by kauri dieback caused by Phytophthora agathidicida. We assessed how health status and season influence plant-available nutrient supply in six plots (24 subplots) spanning symptomatic and asymptomatic stands across three Waitākere Ranges sites. PRS probes measured nitrogen, phosphorus, base cations, micronutrients, and trace metals quarterly from March 2024 to February 2025. Health status affected Cu and Pb availability, with lower availability in symptomatic plots, possibly reflecting reduced rhizosphere activity and organic matter cycling. Season influenced most nutrients: supply was lowest in the austral summer, likely because dry soils limited diffusion while plant demand increased. NH4+ increased in winter, consistent with reduced uptake and suppressed nitrification under cool, wet conditions, whereas NO3- remained low and showed no health or seasonal response. Seasonal controls, therefore, dominated nutrient availability, while disease symptoms were associated with targeted elemental shifts. Repeated in-situ measurements clarify nutrient dynamics in disease-affected forests.</p></td></tr></table><p></p> 2026-09-29T23:40:21Z Image Poster 10.17608/k6.auckland.34027398.v2 https://figshare.com/articles/poster/Effect_of_Season_and_Health_Status_on_Nutrient_Dynamics_in_Diseased_Agathis_Australis_Forests/34027398 CC BY 4.0