![]() There are two rainfall peaks, from March to May and September to November (Institute of Tropical Forest Conservation ). The climate in Bwindi is equatorial with an annual mean rainfall of 1525 mm and an annual mean temperature of 18.4°. The vegetation is classified as “medium altitude moist evergreen forest” and “high altitude sub‐montane forest” (Langdale‐Brown et al., 1964). and covers an area of 331 km 2 on a steep and rugged terrain. Bwindi Forest, in southwestern Uganda, ranges from 1190 to 2560 m a.s.l. Our observations in the montane tropical forest of Bwindi Impenetrable National Park indicate otherwise. A pantropical study of tree mortality and damage, which involved over 150,000 trees, concluded that lightning damage was rare (Arellano et al., 2020)-with only a single tree in Pasoh (Malaysia) believed to bear a lightning scar (G. While commonly noted in temperate forests, scars are considered rare in the tropics as they have seldom been reported from surveys (Gora & Yanoviak, 2020 Parlato et al., 2020 Yanoviak et al., 2017). These methods do not make use of lightning scars because such scars appeared to be too infrequent. Previous studies have identified putative lightning strikes from the presence of perceived flashover damage, defined as the defoliation of the nearest branches in two (or more) adjacent trees and caused by electricity crossing an air gap between neighboring tree crowns (Yanoviak et al., 2017). However, for such field methods, it is important to define practical criteria that can be used to identify lightning strikes with reasonable confidence. Field‐based survey methods have been used to identify past strikes, and are relatively cheap and easy. However, these methods are expensive, challenging to implement, and cannot identify past strikes. Methods that have been used to detect lightning‐struck trees include camera‐based systems to locate lightning strikes in near real time (Yanoviak et al., 2017) and sensors that monitor electrical fields (Bitzer et al., 2013). Further studies in the same forest suggested that lightning strikes generate around 20% of annual gap area (area encompassing the crowns of dead and severely damaged canopy trees) and 13% of total woody biomass mortality (the sum of dead tree biomass and the cumulative necromass associated with crown dieback per strike) (Gora et al., 2021).Īlthough anecdotal observations of trees struck by lightning are common in the tropics (Anderson, 1964 Furtado, 1935 Magnusson et al., 1996), quantified evaluations remain difficult due to the challenge of consistently and objectively identifying impacted trees. ![]() ![]() Moreover, lightning is an important cause of large tree mortality on BCI, with strikes estimated to cause the death of around half of all trees >60 cm in diameter (Yanoviak et al., 2020). A more recent study of strikes in Barro Colorado Island (BCI), Panama, estimated that each damaged on average 23.6 trees >10 cm in diameter, of which 5.5 died within a year (Gora et al., 2020). A study on tree mortality on Krakatau, Indonesia, found that lightning strikes are a major cause of tree death, often resulting in single dead trees with split or charred trunks, and sometimes in several dead trees (Whittaker et al., 1998). Observations suggest that lightning can shape forest dynamics (Anderson, 1964 Brünig, 1964) and tree species composition (Richards et al., 2021). Lightning in the tropics does not only kill gorillas but also impacts trees and forests. The tree, A. salicifolia, was struck on August 14, 2022, a few days before our survey. (g) The only case of branched scar observed in our study. According to witnesses, the tree was struck in 2015. The marks left by lightning on this tree are peculiar since they are discontinuous. (e) Agauria salicifolia struck by lightning on August 10, 2022, a few days before our survey. (d) The lightning scar on this F. laurifolia consists of a system of parallel fissures that develops longitudinally until the ground. (c) A wide and relatively old lightning scar spirals around the trunk of a Ficalhoa laurifolia tree, which is still alive. (b) Dead F. saligna showing a long and straight lightning scar. The lightning killed a Gorilla and left a scar that at the time marked the trunk of the tree along its entire length, but which is now healing and is no longer than 2 m. (a) Faurea saligna struck by lightning on April 7, 2015. These are characterized by a long furrow along the trunk and, around it, the removal of a portion of bark, which width can vary from few centimeters (a, e–g) to a few tens of centimeters (b–d). Seven trees with proposed lightning scars.
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