Utility of commercial high‐resolution satellite imagery for monitoring general flowering in Sarawak, Borneo

General flowering (GF), irregular synchronous mass flowering of multiple tree species across multiple families, is a unique biological phenomenon of the mixed lowland dipterocarp forest in Southeast Asia. Characterizing the spatial extent and temporal dynamics of GF is essential for an improved understanding of climate–vegetation interactions and the potential climate change impact on this species-rich rainforest. We investigated the utility of newly available high-temporal (daily) and high-spatial (3–4 m) resolution remote sensing by the PlanetScope commercial satellite constellation for detecting flowering trees in a dipterocarp rainforest at Lambir Hills National Park, Sarawak, Malaysia. Our study was focused on the latest GF event known to have occurred in the region in the year 2019. PlanetScope successfully acquired 13 clear-sky or minimally cloud-contaminated scenes over the park during a study period of January 1, 2019 to August 31, 2019 encompassing the 2019 GF event. In situ phenology observations verified that the PlanetScope images detected the flowering crowns of tree species that turned into white or orange. This multitemporal image dataset also captured the flowering peak and species differences. The correlation coefficients between the multitemporal image signatures and in situ phenology observations were moderate to very strong (0.52–0.85). The results indicated that the 2019 GF event was a whole-park phenomenon with the flowering peak in May. This study reports the first successful satellite-based observations of a GF event and suggests the possibility of regional-scale characterization of species-level phenology in the dipterocarp forest, key information for biodiversity conservation in Southeast Asia

Structure–function studies of ultrahigh molecular weight isoprenes provide key insights into their biosynthesis

Some plant trans-1,4-prenyltransferases (TPTs) produce ultrahigh molecular weight trans-1,4-polyisoprene (TPI) with a molecular weight of over 1.0 million. Although plant-derived TPI has been utilized in various industries, its biosynthesis and physiological function(s) are unclear. Here, we identified three novel Eucommia ulmoides TPT isoforms—EuTPT1, 3, and 5, which synthesized TPI in vitro without other components. Crystal structure analysis of EuTPT3 revealed a dimeric architecture with a central hydrophobic tunnel. Mutation of Cys94 and Ala95 on the central hydrophobic tunnel no longer synthesizd TPI, indicating that Cys94 and Ala95 were essential for forming the dimeric architecture of ultralong-chain TPTs and TPI biosynthesis. A spatiotemporal analysis of the physiological function of TPI in E. ulmoides suggested that it is involved in seed development and maturation. Thus, our analysis provides functional and mechanistic insights into TPI biosynthesis and uncovers biological roles of TPI in plants

Effects of Pieris japonica (Ericaceae) dominance on cool temperate forest altered-understory environments and soil microbiomes in Southern Japan.

The number of plants unpalatable to deer increases with increasing deer numbers. In the Kyushu Mountain area of Southern Japan, Pieris japonica (Ericaceae), an unpalatable shrub, has become the monodominant vegetation under evergreen conifer and deciduous broad-leaved tree stands. The monodominance of unpalatable plants in the understory has potential advantages and drawbacks; however, the effects of Pieris dominance are not well understood. To assess the effects of P. japonica dominances on forest environments and ecosystems, we investigated understory environments and soil microbiomes in Pieris-dominant sites. Under the deciduous broad-leaved trees, Pieris dominance leads to considerable Pieris leaf litter and humus weights and low soil bulk density and canopy openness. In the soil fungal community and fungal functional groups, the relative abundance of symbiotrophic fungi, particularly ectomycorrhizal fungi in Pieris-dominant sites were lower than in other-vegetation understory sites and saprotrophic fungi vice versa. Because few seedlings and saplings were found under Pieris shrubs, Pieris dominance in the understory might exclude other plant species. The results of this study will contribute to the Pieris population and forest management following deer overgrazing

Fig 1 -

Proportions of the relative abundance of each microbial taxon: a) prokaryotes and b) fungi. In b), root-associated fungi in Pieris root samples are shown on the right side.</p

<i>Pieris</i> sapling information for assessing root-associated fungi.

Pieris sapling information for assessing root-associated fungi.</p

Environmental properties of the sampling points with the results of linear-mixed-model analyses of the effects of understory vegetation and canopy trees.

Environmental properties of the sampling points with the results of linear-mixed-model analyses of the effects of understory vegetation and canopy trees.</p

Fig 2 -

Nonmetrical dimension scaling plot of two microbiomes based on Bray–Curtis indices and significant environmental variables detected via the envfit function (see Table 3, p Pieris, and the open dots indicate samples from under other understory vegetation.</p

Effects of the investigated environmental variables on prokaryotic and fungal communities analyzed using the envfit function for the nonmetric multidimensional scaling (NMDS) analysis.

Effects of the investigated environmental variables on prokaryotic and fungal communities analyzed using the envfit function for the nonmetric multidimensional scaling (NMDS) analysis.</p

Location of the research regions (Maruju, M; Hirono, H).

Pieris dominated sites were shown with odd numbers (M01, M03, M05, H01, H03, H05, and H07). Sites with other vegetation (sites with even numbers) were located near the sites with odd numbers. (TIFF)</p

Results of the linear-mixed-model analyses of the relative abundance of fungal guild with two environmental variables and the read count (%) of root-associated fungi in the <i>Pieris</i> root samples.

Results of the linear-mixed-model analyses of the relative abundance of fungal guild with two environmental variables and the read count (%) of root-associated fungi in the Pieris root samples.</p