Earticle

To evaluate effects of ligninolytic enzyme type on the mycelial response and ligninolytic enzyme production during interspecific interactions among wood-rotting fungi, 4 fungal strains, Trichophyton rubrum LKY-7, Trichophyton rubrum LSK-27, Pycnoporus cinnabarinus, and Trichoderma viride, were selected. Regarding ligninolytic enzyme production, LKY-7 secreted laccase and manganese peroxidase (MnP), P. cinnabarinus secreted only laccase, and LSK-27 secreted only MnP in glucosepeptone medium, while T. viride did not produce any ligninolytic enzymes. In the co-culture of LKY-7 with P. cinnabarinus, the formation of aerial mycelium was observed and the enhancement of laccase activity owing to interspecific interaction appeared to be very low. In the co-culture of LKY-7 and P. cinnabarinus with LSK-27, a hypha-free clear zone was observed, which resulted in deadlock, and increased laccase or MnP activity was detected at the interaction zone. The interaction responses of LKY-7, P. cinnabarinus, and LSK-27 with T. viride were characterized by the formation of mycelial barrages along the interface. As mycelial barrages were observed at the T. viride territory and no brownish pigment was observed in the mycelial barrages, it is suggested that laccase and MnP are released as part of an offensive response, not as a defensive response. The co-culture of P. cinnabarinus with T. viride lead to the highest enhancement in laccase activity, yielding more than 14-fold increase in laccase activity with respect to the mono-culture of P. cinnabarinus. MnP activities secreted by LKY-7 or LSK-27 was generally low in interspecific interactions.

The negative impact of monoculture rubber plantations on biodiversity and associated ecological processes/ecosystem services has led to suggestions on the use of integrated land use systems for rubber cultivation and production in order to ensure environmental sustainability. However, there is paucity of information on the effect of such integrated land use systems on the diversity and abundance of the rubber plantation undergrowth. We evaluated and compared undergrowth plant species composition, richness, abundance, diversity and interaction, in three integrated systems (Rubber-Strelitzia reginae Integrated System - RSrIS, Rubber-Podocarpus nagi Integrated System – RPnIS & Naturally Managed Rubber Plantation - NMRP) with three Rubber Monoculture Plantations (RMP1, RMP2 & RMP3) adjacent to the integrated systems, respectively, at the Investigation and Experiment Station of Tropical Crops, Danzhou, Hainan, China. Undergrowth species density was higher in the rubber monocultures than in the integrated systems except in RSrIS. Species richness and diversity were also higher in the monocultures except in NMRP. Species similarity/interaction between the monocultures and the integrated systems was highest between RMP3 and NMRP. The NRMP proved to be the best model of natural rubber integrated system for the conservation of undergrowth species richness, diversity and interspecific interaction. However, the conservation of undergrowth species in other forms of integrated natural systems can be enhanced by considering the ecology of species to be integrated in terms of their growth characteristics, competitive nature, and ability to grow in association with other species.

Studying activity patterns of species is essential to understand their ecological strategies for survival. This study aimed to explore inter-specific interaction between the Siberian chipmunk (Eutamias sibiricus) and the red squirrel (Sciurus vulgaris) by analyzing their activity pattern at both spatial and temporal aspects. In order to confirm whether their habitat selection interferes with each other, we examined effects of season and competition on chipmunk's habitat selection using a camera-trapping method and zero-inflated negative binomial models. Further, we analyzed how much their temporal niche is overlapped using the Kernel density curves of their active time and the overlap coefficient. The chipmunk's occurrence was positively influenced by squirrel's occurrence, which implies overlap between their habitat niche. Further, temporal niches of the chipmunk and squirrel shifted across seasons, likely influenced by seasonal variation in inter-specific competition. Increased population density or activity levels during reproductive periods or fall could intensify their competition pressure, potentially leading to their temporal niche partitioning. This study highlights the dynamic nature of interspecific competition and underscores the importance of temporal niche differentiation in facilitating coexistence between sympatric species. Understanding these ecological dynamics is critical for developing conservation strategies to promote species coexistence under changing environmental conditions. Futhermore, the findings provide valuable insights for managing biodiversity and sustaining healthy forest ecosystems.