Alien plant species can pose a threat to biodiversity when their spread becomes uncontrollable. Acacia species have been observed to invade not only roadside areas but also residential zones, agricultural lands, and forest edges, despite the absence of intentional planting. The construction of highways significantly contributes to its spread, as large-scale linear disturbances create favorable conditions for invasive species across these diverse environments. Hence, roads should form a main target for invasive species management. To inform conservation and aid management of invasive species it is crucial to study the spread and abundance of non-native species and their impact on native ecosystems. This study is aimed at mapping Acacia species (4. mangium and close relatives) distribution, and abundance, along the recently opened Telisai-Lumut highway which was constructed along the edge of a Forest Reserve, Aerial images were obtained for 10 sample sites along the highway by using Unmanned Aerial Vehicle (UAV) apparatus (Phantom 4, DJI Mavic 2 Pro, and DJI Mavic 2 Air) which were flown over the area of interest. Acacia's location and abundance were determined up to 200 m distance from both sides of the highway for the 10 sample sites. We found over 2077 Acacia trees in the 10 sample sites, 840 trees (23.9 trees/ha) on the coastal side of the road and 1237 trees (20.5 trees/ha) at the Andulau Forest Reserve side (inland) of the road. Acacia occurrences varied, depending on elevation, land use, availability of open area, and distance to the road. Our study shows that the highway provided an opportunity for Acacia species to spread along the open road edges and in some cases merge into the forest edge. The presence of these Acacia's near the forest edge forms a potential threat for forest integrity in the future. While it may not readily invade closed canopy forests, the more open canopies at forest edges create conditions where it can outcompete native trees, potentially altering the composition and dynamics of these ecosystems in the future. Using UAVs provided a cost-effective method of monitoring the presence and abundance of Acacia trees in the research area and may thus be an important tool for efficient management of this invasive species.

Although morphological adaptations leading to crypsis or mimicry have been studied extensively, their interaction with particular behaviors to avoid detection or recognition is understudied. Yet animal behaviors interact with morphology to reduce detection risk, and the level of protection conferred likely changes according to the surrounding environment. Apart from providing a locational cue for predators, prey motion can also serve as concealing behavior in a dynamic environment to prevent detection by potential predators or prey. Phasmids are conventionally known to rely on their adaptive resemblance to plant parts for protection, and this resemblance may vary across life stages and species. However, little is known about how their behaviors interact with their appearance and their environment. We investigated two species of phasmids with varying morphology and color patterns at different ontogenetic stages and examined their behavioral responses to a wind stimulus as a proxy for a dynamic environment. While adult behaviors were mostly species-specific, behavioral responses of nymphs varied with appearance and environmental condition. Display of different behaviors classified as revealing was positively correlated, while the display of concealing behaviors, except for swaying, was mostly negatively correlated with other behaviors. Exhibition of specific behaviors varied with appearance and environmental condition, suggesting that these behavioral responses could help reduce detection or recognition cues. We discuss the differences in behavioral responses in the context of how the behaviors could reveal or conceal the phasmids from potential predators. Our results provide a novel investigation into adaptive resemblance strategies of phasmids through the interaction of behavior and morphology, and highlight the importance of considering the effects of dynamic environments on sending and receiving cues.

Terrestrial and epiphytic herbaceous forest species have different ecology and leaf stoichiometry. In tropical regions, a great component of herbaceous forest species is represented by ferns with different lifeforms. However, little is known about the differences in leaf stoichiometry between the lifeforms. We account for the concentrations of leaf elements (N, P, K, Ca and Mg) between terrestrial and epiphyte lifeforms and evolutionary clades. The fern species were sampled from the forest of Brunei Darussalam. Five leaves were collected from 5 individuals from 16 terrestrial and 4 epiphytic ferns. The leaves were then acid-digested and analyzed. Epiphytic species had higher concentration of most of the leaf elements. The N:P ratio showed that the epiphytic species being much more nutrient-limited, relying on stochastic events, compared to the terrestrial species which have a constant availability of soil elements. Epiphytes showed a higher concentration of P, which could be explained by their luxury consumption. Epiphytes accumulate elements in a higher concentration than is needed by their normal metabolic activity. Furthermore, epiphyte species have a signi􀂦cantly higher concentration of Ca which could be interpreted as necessity of coping with severe habitat conditions with schlerophyll leaves. The results bring in more information on the poorly studied stoichiometry of tropical Asian fern species. Important in understanding the eco-physiology of terrestrial and epiphytic ferns and determining which species are sensitive to the different forest management and the effect of climate change. This, is in addition to the associated mechanisms.

Tropical peat swamps are essential ecosystems, which provide numerous services, and also serve as a rich source of dissolved organic carbon (DOC), hydrogen ions and trace elements to peat draining rivers. However, not much is known about trace element export from tropical peat swamps. We investigated trace element dynamics in rivers and estuaries draining tropical peat swamps on Borneo, and examined the influence of estuarine processes as well as dissolved organic carbon (DOC) on the distribution and concentration of trace elements. Our results indicate acidic conditions (pH = 3.3) and high DOC concentration (3500 μmol L−1) at salinities<1. We observed an initial release of trace elements at low salinity (0.05