The long-term effect of typhoons on vascular epiphytes in Taiwan

Abstract

Abstract:We used all 167 typhoon warnings issued by the Taiwanese Central Weather Bureau from 1958–2006 to assess the long-term effect of cyclone disturbance on vascular epiphytes. Tracks and eyes of past typhoons were plotted as circles with radii of Beaufort scale 7 and 10, and the frequency of each cohort in 1-km2 grid cells was calculated. The presence of vascular epiphytes in the same grid cells was predicted using species distribution models (SDMs). First, we used herbarium specimens and other sources to compile a comprehensive georeferenced vascular epiphyte database that contained 39084 records in 331 species. Next, we assigned each epiphyte record to a cell in the same 1-km2 grid as above. Finally, we used SDMs (MaXent), based on 30 environmental variables except typhoon frequency, to predict the potential presence of each species in the grid cells. For our analysis we only considered cells east of the central mountain ridge where typhoons hit with full force. After elimination of rare species and species that could not be validated in the SDMs, we were left with 156 epiphyte species in 10725 1-km2 cells. The number of projected species in the cells was 36.5 on average, varying between two and 82 species. Correlation analyses showed that, over time, typhoons led to a decrease in epiphyte richness at Beaufort scale 7 and 10 (Pearson's r = −0.07 and −0.08 respectively). Ferns, orchids, hemiepiphytes and dicotyledons generally showed the same pattern, except hemiepiphytes that showed a positive correlation at B7 (Pearson's r = 0.15). A partial canonical correspondence ordination analysis showed that, independent of temperature- and rainfall-related variables, Beaufort scale 7 and 10 typhoons also had significant influence on the species composition of the vascular epiphyte communities in the landscape. We recommend in situ monitoring of epiphytes over a long period to corroborate the suggestion from this indirect study that typhoons have a long-term effect on the distribution of epiphytes in Taiwan.

Herbaceous plant diversity in forest ecosystems: patterns, mechanisms, and threats

“…Similar climate-driven shifts in community composition have been reported for forest trees, as well as for plant communities in other ecosystems (Feeley et al 2020). Future models should incorporate the effects of increased extreme weather events and variability (e.g., Hsu et al 2018;Kennard et al 2020) and potential positive feedback from climate-induced overstory decline (e.g., Zellweger et al 2020), as well as more information on intraspecific variation in traits (e.g., specific leaf area) that could contribute to the adaptation of herbaceous plant communities to global change (Blondeel et al 2020).…”

Complex consequences of disturbance on canopy plant communities of world forests: a review and synthesis

“…In most cases, the effects of hurricanes negatively affected EM. For example, following hurricanes in Mexico, Honduras, and Taiwan, epiphyte abundance and diversity were significantly reduced in dry and wet temperate and tropical forests (Goode & Allen, 2008; Batke & Kelly, 2015; Hsu et al ., 2018; Novais et al ., 2020). Extreme wind events also reduced the height location within trees in Honduras (Batke & Kelly, 2015), and fire in Florida (Robertson & Platt, 2001).…”

“…Waide & Kingsland, 2021), but are critical to understand disturbance effects on slow-growing species such as epiphytic shrubs and their host trees. The use of modeling approach have expanded these scales; for example, Hsu et al (2018) suggested that by 2100, the majority of epiphyte species were projected to lose 45-60% of their current range, shifting to higher elevation areas.…”

“…The use of modeling approach have expanded these scales; for example, Hsu et al . (2018) suggested that by 2100, the majority of epiphyte species were projected to lose 45–60% of their current range, shifting to higher elevation areas.…”