Fire and the reproductive phenology of endangered Madagascar sclerophyllous tapia woodlands

Abstract

International audienceKeywords: Reproductive phenology Fire Tapia woodland Uapaca bojeri Ibity mountain Tapia woodland vegetation is a remnant of Madagascar sclerophyllous forest that has developed under the selective pressure of fire and is dominated by the endemic tree Uapaca bojeri (Phyllanthaceae), locally named tapia. We carried out a 2-year study in tapia woodland at Ibity mountain, a new protected area in central highlands of Madagascar. We aimed to describe the reproductive phenology of this vegetation type and to determine whether it is affected by fire. We addressed two main questions: 1) does fire frequency affect the proportion of reproducing individuals and the intensity of each flowering and fruiting event?; and 2) does fire frequency influence the reproductive synchrony of species across the landscape? Thirteen woody species (373 individuals) were sampled at six sites selected across the Ibity mountain, where three that were burned three times between 2000 and 2010 and three burned just once during the decade. We found that (1) fire reduced the percentage of individuals that participate in each phenophase, and flower and fruit production was lower at the more frequently burned sites; and (2) increased fire frequency reduced the reproductive synchronization of species throughout the landscape. Fire is recognized as one of the major disturbances affecting mortality and recruitment of trees in tapia woodland. Our study indicates that fire also impacts the timing of plant reproduction at community and landscape levels

Drivers of fire occurrence in a mountainous Brazilian cerrado savanna: Tracking long-term fire regimes using remote sensing

“…The timing of fire occurrence is also relevant to determine the damages to leafing, flowering, fruiting and/or germination processes, impacting seedlings and reducing recruitment, as well as favoring specific groups of species that are fire tolerant or fire resistant (Alvarado et al, 2015(Alvarado et al, , 2014Hoffmann, 1998). The peak in active fires, observed on MODIS data from Serra do Cipó between the end of the dry season and the beginning of the wet season (September and October), is consistent with other cerrado studies.…”

Effects of heat on the germination of sclerophyllous forest species in the highlands of Madagascar

“…Fruit production and dispersal of tapia woodland species occur mainly during the rainy season, between November and May (Alvarado et al . ), a pattern that is also observed in some other tropical ecosystems, such as the Cerrado (Batalha & Mantovani ; Weiser & Godoy ) and the Atlantic forests (Morellato et al . ) of Brazil.…”

“…A phenology study performed on selected woody tapia woodland species (Alvarado et al . ) showed that seed dispersal takes place during the rainy season for five of the species studied: A. ibityensis , A. theiformis , C. edulis , U. bojeri and V. secundiflorum . Seed germination of these and other woody species is potentially linked to rainfall because precipitation brings an increase in soil moisture, which promotes germination (Oliveira & Silva ; Baskin & Baskin ).…”

“…) and the other species are common in the lower canopy and mid‐storey; and (ii) these species are endemic to Madagascar and are potentially threatened by changes in fire regimes (Alvarado et al . ). It is thus important to study their biology within the context of future conservation, restoration or reinforcement programmes.…”

Reproductive phenology of Sambucus nigra subsp. canadensis in the Abies religiosa temperate forest of the Magdalena river basin, Mexico City

“…For example reproductive phenology of the individuals in group three, did not show any relation with the evaluated micro-environmental variables. Other random factors, or the genetic constitution of individuals, plant diseases, pollination interactions, dispersal and predation can influence the variability of reproductive patterns (van Schaik et al 1993, Cuevas-García et al 2013, Alvarado et al 2014. Likewise, the temporal variability between years can display the relation between environmental factors and the production of reproductive structures at a finer scale (Sherry et al 2007).…”