While the canopy layer shows the highest productivity in forests, it also has the highest herbivore population density. How do canopy trees cope with attack from herbivores under such conditions? We investigated the relationship between leaf flushing phenology, defensive and photosynthetic traits, such as leaf flushing frequency, the number of emerging leaves per flushing term, the leaf life span, total phenolic and condensed tannin contents, leaf toughness, leaf nitrogen content, the photosynthetic rate at light saturation (P_max) and leaf mass per area (LMA), in canopy trees of five dipterocarp species in a Malaysian tropical rain forest. Interspecific variations were clearly observed in leaf flushing frequency, ranging from occasional to continuous patterns. The total phenolic content significantly increased with leaf flushing frequency. Leaf toughness showed no correlation with leaf flushing phenology, but species with occasional leaf flushing had greater leaf toughness than those with continuous leaf production. There was a negative correlation between leaf toughness and tannin content, and a positive correlation between the former and P_max. In addition, the leaf herbivory rate significantly increased with a larger number of emerging leaves per term and a higher comprehensive index (PC1) from PCA analysis using leaf flushing frequency and the number of leaves. Therefore, our results suggest that tropical canopy species have various defensive strategies against herbivore attack by regulating the intensity of chemical, physical and phenological defenses; species with high leaf flushing frequency have more chemically defended leaves, while those with low leaf flushing frequency have tougher leaves with higher photosynthetic abilities.

Twenty years of long-term maize monoculture that began in the 1990s have resulted in the heavily maize-dependent economy of the northwestern mountainous region of Vietnam, especially in Yen Chau, the core production area. Before 2014, maize accounted for over 70% of the agricultural area. The continuous decrease in maize production value has strongly affected the Tai Dam community in Yen Chau and led to the replacement of various livelihood activities. This contributed to a major shrinkage of the maize area by 28.2% by the end of 2017. This study aims to investigate the determinants of the rapid development of different livelihood trends in Lac Ken, Suoi Bun, and Luong Me villages. A detailed social and statistical investigation was conducted of 198 households in 2016 and 220 households in 2017. The findings of this study indicate that small differences in cultivated land areas and infrastructure facilities have fostered the formation of and changes in livelihood structures. The areal withdrawal of maize occurred concurrently with the increasing trend of fruit tree and sugarcane cultivation. Never-before-seen migrant work unexpectedly became a promising livelihood activity for local farmers. Differences in internal and external forces are believed to be the driving factors behind the new forms of livelihood activities.

Three specimens of Egesina (Callienispia) elegans (Fisher, 1925) are first recorded since 1925 as the first representative from East Kalimantan, Indonesia with detail description, fine quality figures, and brief notes.