Tasmanian Institute of Agriculture, University of Tasmania, Hobart, 7001, Australia.
Agriculture Victoria, Tatura, Australia.
Sci Rep. 2022 Dec 5;12(1):21031. doi: 10.1038/s41598-022-25207-0.
Protected cropping systems (PCS) alter the plant growing environment, though understanding of this in ventilated systems and how the new climate affects tree water uptake is limited. Sap flow sensors and weather stations were deployed in 16-year-old 'Lapins' on 'Colt' rootstock cherry trees under a ventilated Voen PCS and in an adjacent bird netted PCS. Average and maximum temperatures were consistently higher (14.7 °C and 22.9 °C) while total daily solar radiation and average wind were consistently lower (12.9 MJ/m and 0.2 m/s) in rain covered, in contrast to netted, PCS (13.9 °C, 21.3 °C, 13.7 MJ/m and 0.9 m/s). Over the season, a threefold lower daily sap flow rate was observed under rain covered PCS. Using generalised additive modelling (GAM), the influence of individual climate parameters on sap flow were predicted. Whilst sap flow was only slightly affected by relative humidity (RH) less than 60%, above this threshold sap flow rapidly declined under rain covered PCS whereas sap flow more gradually declined above 20% RH under netted PCS. Overall, our novel modelling approach led to the discovery of the 60% RH critical threshold on predicted sap flow and the indirect effect that wind speeds have on sap flow under PCS.
保护地栽培系统（PCS）改变了植物生长的环境，但对于通风系统中的这种情况以及新气候如何影响树木水分吸收的理解有限。在通风 Voen PCS 和相邻的鸟类网罩 PCS 下，在 16 年生的‘Lapins’上的‘Colt’砧木樱桃树上部署了 sap 流量传感器和气象站。在有雨覆盖的情况下，平均和最高温度始终较高（分别为 14.7°C 和 22.9°C），而总日太阳辐射和平均风速始终较低（分别为 12.9 MJ/m 和 0.2 m/s），与网罩 PCS（13.9°C、21.3°C、13.7 MJ/m 和 0.9 m/s）形成对比。在整个季节中，在有雨覆盖的 PCS 下，每日 sap 流量率低了三倍。使用广义加性模型（GAM）预测了单个气候参数对 sap 流量的影响。尽管 sap 流量仅受相对湿度（RH）低于 60%的轻微影响，但在该阈值以上，有雨覆盖的 PCS 下 sap 流量迅速下降，而在网罩 PCS 下，RH 高于 20%时 sap 流量逐渐下降。总的来说，我们的新模型方法发现了预测 sap 流量的 60%RH 关键阈值，以及风速对 PCS 下 sap 流量的间接影响。
