Is leaning trees of Vatica pauciflora (Korth.) Blume related to their crown architecture?

Vatica pauciflora (Korth.) Blume (Dipterocarpaceae) or locally known as resak rawa is an important tree. It is categorized as vulnerable regarding the IUCN (International Union for Conservation of Nature) Red List of Threatened Species. We can find the resak rawa tree collection in the Bogor Botanic Gardens, which serves as a place for research and tourism. Due to the diversity in individual tree anatomy within species, understanding correlation among individual tree traits, particularly crown architecture and tree leaning, is of great interest. That will be important because the leaning trees and crown architecture will affect the risk level to the safety of visitors. We can also use the architecture of the tree crown to understand the factors that influence tree growth. This study aims to investigate the correlation between the leaning trees and the crown architecture of V. pauciflora. Eight heritage trees of the species in the Bogor Botanic Gardens at the age of 54–105 years old were purposely, sampled in this study. The variables observed were height, trunk and crown diameter, leaning tree, live crown ratio, and direction of the main branches. The results show that crown shapes will follow the leaning trees with a correlation of 0.97. The main branches will be longer in the direction of the leaning trees (y=0.9956x+11.312; R²=0.9431). Suggestions to the management of V. pauciflora are to provide information boards to visitors and pruning the crown in the direction of the leaning trees is needed. The findings could be used to formulate mitigation measures as to the risk and safety of visitors.

Crown architecture of Quercus robur L. in the reproductive period of ontogenesis in phytocoenoses of the northern forest-steppe in the Tula Region

The diversity of the habitus in reproductive individuals of Quercus robur L. in phytocoenoses of the northern forest-steppe within the Kulikovo Pole museum-reserve in the Tula Region was analysed. The individuals grow-ing in the ravine and upland closed and open forests as well as open-growth individuals and groups of individu-als in the forest outliers were researched. One-trunk, a few-trunk, coppice and clump life forms were detected. It was shown that the types of the habitus or architectural types (AT) in reproductive individuals resulted from those AT that were firstly described in the virginal ontogenetic state and in the beginning of the young reproduc-tive state in the mixed forest and broadleaved forest biomes. The quantitative and qualitative changes of the shoot systems were found out. The ways of the crown transformation are ten in number. They include acropetal mortality of the branches from the trunk, basipetal mortality of the shoot systems, decrease of the trunk branch-ing frequency, secondary crown formation, trunk deviation from the orthotropic growth direction, increase of the polyarchic plan of organization in trunk, trend of branch drooping, disarrangement in crown zoning, increase of the polyarchic plan of organization in branches, immediate reiteration. The most survived initial crown architec-ture is expressed in the open-growth individuals that grow on the slow slopes. The most common way of trans-formation is acropetal mortality of the branches from the trunk. Its intensity depends on the closeness of the stand. Besides light level, crown architecture in the reproductive period of ontogenesis is influenced by the indi-vidual’s position in relief, which affects the aerologic and hydrologic regimes of the phytocoenosis.

Is there tree senescence? The fecundity evidence

Despite its importance for forest regeneration, food webs, and human economies, changes in tree fecundity with tree size and age remain largely unknown. The allometric increase with tree diameter assumed in ecological models would substantially overestimate seed contributions from large trees if fecundity eventually declines with size. Current estimates are dominated by overrepresentation of small trees in regression models. We combined global fecundity data, including a substantial representation of large trees. We compared size–fecundity relationships against traditional allometric scaling with diameter and two models based on crown architecture. All allometric models fail to describe the declining rate of increase in fecundity with diameter found for 80% of 597 species in our analysis. The strong evidence of declining fecundity, beyond what can be explained by crown architectural change, is consistent with physiological decline. A downward revision of projected fecundity of large trees can improve the next generation of forest dynamic models.

Tree crown economics: testing and scaling a functional-trait based theory

<p>The relationship of tree form and function has long fascinated humans, and now, much of our ability to improve maps and forecasts of the vital interactions of forests and global change hinges on our ability to understand this adaptive tree crown architecture.  To help address this challenge, I revisit Henry Horn’s classic 1971 monograph “The Adaptive Geometry of Trees”, and blend his theoretical framework with a contemporary ecological theory of species’ functional traits.  Then, I describe how this trait-based theory tree crown architecture can be robustly tested using state-of-the-art hyper-remote sensing techniques.  This suite of imaging techniques from hyper-spatial (e.g. UAV and satellite imagery), hyper-spectral (e.g. AVIRIS imagery), hyper-temporal (e.g. phenocams and tree- or tower-mounted time-lapse cameras), and hyper-dimensional (terrestrial and UAV LiDAR) sensors now enables us to visualize and measure the spectral and architectural properties of individual trees with unprecedented accuracy and precision.  Through analysis of hyper-remote sensing datasets collected in forests across eastern North America, I highlight how this testable trait-based theory of tree crown economics is already providing fresh insights into several important, but heretofore unresolved patterns of spatial and temporal variability in forest functioning.    </p>