Investigating the Rainforest Canopy Phenology Variation and Productivity Responses to Drought by Using Digital Camera Images

Among the natural disturbances, drought may cause significant change in forest ecosystems by shifting phenology and productivity. Digital cameras have been used phenological observations for their high accuracy colour index values (digital-number of red, green blue) derived from long-term continuous digital camera imagery are useful as proxies investigating a canopy’s response to drought. Here, we examine interaction between indices (the strength red (Sred), (Sgreen), excess (GEI)), productivity (gross primary (GPP)) (standardised precipitation evapotranspiration (SPEI)) climatic factors. We use canopy images flux tower-based 2010 2016 show rainforest’s responses The SPEI indicated occurrence condition 2014. lowest (-0.403 mmday-1), total (1062 mmyr-1), highest average air temperature (21.3 C)”, need be changed like that “the (21.3°C)”, put Degree symbol 21.3 C, potential (3.31 mmday-1) rain efficiency (2.26 gCL-1) were found Leaf color variation period (CVP) become longer with an advance foliage green-up after peak GEI at end CVPs. GPP Sgreen had positive Sred negative relationship index. dropped during bounced back due leaf CVP. significantly (p<0.05) related During CVP drought, correlated P, PET Ta, meanwhile, there was only avg Ta. variables, more (p < 0.001) There also factors on yearly time series. Our results indicate understanding rainforests which might ecologists when predicting effects future rainforest