English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Spatial and temporal variations in light-saturated photosynthetic capacity and needle nitrogen (N) content were investigated in one 8 m tall Japanese cedar ( D. Don) canopy for a full year. The photosynthetic capacity and needle N content in various layers of the canopy were measured every month. Temporal variations in photosynthetic capacity and needle N content expressed on a projected-area basis (P, N) were similar. Furthermore, both P and N decreased with increasing depth from the top of the canopy on each sampling date. As a consequence, a significant correlation was observed between N and P. Temporal variations in photosynthetic capacity and needle N content expressed on a mass basis (P, N) were also similar. P also decreased with increasing canopy depth. However, in contrast to N, there was only a slight decrease in N with increasing canopy depth. Hence, the correlation between N and P was lower than the projected-area value. Because N was highly correlated with the needle mass per projected-area (NMA), the spatial variation in N (and therefore P) in the canopy is attributed to the variation in NMA, which decreases as the depth from the top of the canopy increases. Furthermore, the slope of the linear regression between N and NMA differed between sampling dates, indicating that the temporal variations in N (and therefore P) are strongly influenced by N. For most of the sampling dates, a linear regression between N and P tends to converge into a single line segment. However, on several sampling dates, there was a pronounced decline in P below this line segment. This reduction in P, which does not accompany a reduction in Narea, seems to be attributable to stomatal limitations induced by the low soil temperature in winter and early spring.

Spatial and temporal variations in the photosynthesis-nitrogen relationship in a Japanese cedar (Cryptomeria japonica D. Don) canopy