Distinct germination responses may contribute to the distribution pattern of two Moquiniastrum species in different phytophysiognomies from the Brazilian savanna

Abstract

Understanding how germination traits can influence the distribution pattern of adult plants is still an important issue for seed ecologists and biologists. Here, we evaluated if seed germination responses to abiotic factors may be related to the occurrence of two Moquiniastrum species in different phytophysiognomies from the Brazilian savanna. To evaluate if germination responses are distinct between species, seeds of M. barrosoae (common to typical savanna) and M. polymorphum (common to typical and forested savanna) were set to germinate under different constant (5 to 40 • C) and alternating (15-30, 20-30, 25-30 and 25-35 • C) temperature regimes in light and dark conditions, different red:far-red ratios (0.1, 0.5, 2.0 and 7.2 R:FR) of light, and water availability (0 to −1.0 MPa) in controlled experiments. Seed germination responses were distinct between species, with M. polymorphum presenting higher germinability over a wider temperature range, with lower light requirement for germination, less sensitivity to alteration of R:FR ratios and higher tolerance to water limitation compared to M. barrosoae, which presented more specific environmental requirements to seed germination. Therefore, we demonstrate that seed germination responses may contribute to the distribution pattern observed in adult plants, since the more widely distributed species (M. polymorphum) presented higher germinability over a broader range of environmental conditions, which may enable this species to occur in different phytophysiognomies compared to the species with the more restricted distribution area (M. barrosoae).

Woody plant encroachment constrains regeneration of ground‐layer species in a neotropical savanna from seeds

“…2004; Salazar et al . 2012; Ribeiro and Kolb, 2016). Therefore, as encroachment along with environmental filtering changes occur, it becomes more challenging for typical savanna species to disperse and become established in formerly open savanna areas creating a feedback loop process.…”

“…Seeds were incubated in germination boxes with their sides and bases covered with aluminum foil, while their lids were covered with plastic film (insulfilm ® ) (Simão et al . 2008; Ribeiro & Kolb 2016), so only light through the lids reached the seeds.…”

“…Under fire suppression, seedlings of forest species grow without being topkilled; thus, they will eventually reach a size that allows for fire resistance influencing vegetation structure (Hoffmann et al 2012b). Also, some forest/generalist species have a broad germination niche that may allow their regeneration and establishment in encroached conditions (Hoffmann et al 2004;Salazar et al 2012;Ribeiro and Kolb, 2016). Therefore, as encroachment along with environmental filtering changes occur, it becomes more challenging for typical savanna species to disperse and become established in formerly open savanna areas creating a feedback loop process.…”

Aspectos Dimensionais De Sementes De Dimorphandra Mollis Para Estudo Da Variabilidade Entre Populações De Plantas

“…Fatores como a maior disponibilidade de nutrientes para a planta matriz, bem como fatores ecológicos (por exemplo competição por dispersores), podem ser relevantes na expressão das diferenças fenotípicas nos dois ambientes. Também, deve ser considerado que as condições de radiação nos ambientes de FES e Css são distintas, o que implica em diferentes demandas de consumo/produção para plântulas no início do desenvolvimento (Ribeiro et al, 2016).…”

Efeitos de uso de terra e manejo em populações de Annona crassiflora Mart. no Cerrado

“…No caso do Cerrado, há um mosaico de fitofisionomias distribuídas ao longo de variações edafoclimáticas (Ribeiro & Walter 2008. As variações naturais do solo de composições granulométrica e química são relacionadas ao teor de umidade e fertilidade, características que afetam desde a germinação e estabelecimento de plântulas (Sales et al 2013, Simão et al 2013), e consequentemente de padrões de distribuição de espécies (Ribeiro & Kolb 2016) até o desenvolvimento de todos os estágios de vida (Haridasan 2008, Copeland et al 2012. Adicionalmente, a altitude, que se relaciona ao clima de cada região pode afetar o padrão de distribuição de espécies (Giménez-Benavides et al 2007, Matías & Jump 2015.…”