Longevity of seeds and soil seed bank of the Cerrado tree Miconia chartacea (Melastomataceae)

Abstract

Miconia chartacea is a widely distributed tree in Brazil, occurring at altitudes ranging from 300 m to 1900 m in the Caatinga, Cerrado and Atlantic Forest biomes. In this work we attempted to classify M. chartacea seeds regarding their behaviour during storage and their germination syndrome and to determine, from a storage test in Cerrado soil and laboratory conditions in situ and ex situ, the longevity of seeds, as well as the capacity of the species to form a soil seed bank. The results suggested that M. chartacea seeds form a transient soil seed bank in the Cerrado and can be classified as orthodox in terms of storage behaviour, although the seeds are dispersed with a relatively high water content. The life span of seeds was favoured in soil-stored seeds in comparison with dry storage at 25°C, whereas storage at low temperatures prevented a decrease of the seed's germinability with storage time (330 d). M. chartacea seeds are dispersed during the dry season and germinate during the next rainy season, which can be classified as an intermediate–dry germination syndrome. Seeds of this species are dispersed in the Cerrado when temperatures and soil moisture are relatively low, which favours the formation of a soil seed bank, considering that the seeds tolerate desiccation and their longevity is favoured by low temperatures. A transient seed bank type is favoured by the loss of viability in storage at warm temperatures linked to the rainy season, and the predictable seasonal variations in climate in the region, with germination being restricted to the beginning of the rainy season.

Post‐fire regeneration strategies in a frequently burned Cerrado community

“…Additionally, most Cerrado species only form transient seed banks (Velten & Garcia, 2007;Salazar et al, 2011) and recruitment from the seed bank does not seem to be linked to fire, but rather to the onset of the rainy season (Andrade & Miranda, 2014;Escobar & Cardoso, 2015). Nonetheless, all species (except for Mimosa pteridifolia) survived one-minute heat shocks of 100°C and most survived 3-min heat shocks of 100°C, suggesting seed tolerance to these temperatures (R+PT), corroborating what has been observed for species of other fire-prone grassy ecosystems (Gashaw & Michelsen, 2002;Clarke & French, 2005;Dayamba et al, 2008), including the Cerrado (Le Stradic et al, 2015;Fichino et al, 2016;Ramos et al, 2016;Daibes et al, 2019;Zirondi, José et al, 2019).…”

Are the Alien Species of Melastomataceae and Bombacoideae a Potential Risk for Brazilian Cerrado?

“…The seeds were dormant and this condition could be broken at the same time, weeks or months after sowing. The spreading of germination through time is associated with dormancy and this character permits soil seed bank formation for Melastomataceae, as was observed for Clidemia hirta, Miconia chartaceae, Miconia ferruginata, Microlicia fasciculata [36] [54] and Miconia ferruginata (MA Ranal, personal observation). Seeds of Clidemia hirta when unearthed, show a faster and synchronic germination process than seeds stored in paper bags in laboratory conditions [44], and these results represent irrefutable evidence of its ability to survive in soil and form soil seed banks.…”

Seed longevity and physical dormancy break of two endemic species of Dimorphandra from Brazilian biodiversity hotspots

“…(2011) for tree species from the Cerrado. This decrease in the role of seed banks reflects a reduction of seed persistence in the soil, with a smaller proportion of tropical species forming persistent seed banks, both in wet (Vázquez-Yanes and Orozco-Segovia, 1993) or dry (Salazar et al ., 2011; Escobar and Cardoso, 2015) tropical forests. Moreover, Thompson (2000) reported that perennial plants should be expected to invest less in seed persistence, as perenniality allows multiple opportunities for reproduction.…”

“…As soil seed banks have less influence on vegetation dynamics in tropical ecosystems (Skoglund, 1992), other strategies must be responsible for maintenance of plants in these environments, and seedling establishment may be primarily controlled by the timing of dispersal and seed dormancy, as reported by Salazar et al (2011) for tree species from the Cerrado. This decrease in the role of seed banks reflects a reduction of seed persistence in the soil, with a smaller proportion of tropical species forming persistent seed banks, both in wet (Vázquez-Yanes and Orozco-Segovia, 1993) or dry (Salazar et al, 2011;Escobar and Cardoso, 2015) tropical forests. Moreover, Thompson (2000) reported that perennial plants should be expected to invest less in seed persistence, as perenniality allows multiple opportunities for reproduction.…”