Navegando por Autor "Heringer, Gustavo"

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Biological invasion by Acacia spp. in the Brazilian Atlantic Forest
(Universidade Federal de Viçosa, 2018-04-20) Heringer, Gustavo; Neri, Andreza Viana; http://lattes.cnpq.br/2987814964691327
Climate change, habitat degradation, and biological invasion are among the most factors threaten biodiversity. These factors, besides affect biodiversity and ecosystem directly, can act synergistically and promote deeper environmental changes. Therefore, in this thesis, we proposed to study the causes and consequences of biological invasion by Acacia genus. In the first chapter, we investigate the effects of biological invasion by Acacia spp., fire and eucalyptus disturbance, and land-use on a neglected sandy-savanna ecosystem named Mussununga; in the second, we tested the effects of landscape functioning and structure in the Acacia invasion in Mussununga ecosystem; and finally, assessed the potential distribution of Acacia mangium and A. auriculiformis in five climate scenarios and the potential effects in restoration programs. We found in the first chapter that Acacia promoted changes in the structure and phytophysiognomie of the woody layer, but did not affect the herb-shrub layer. On the other hand, anthropogenic factors affected both woody and herb-shrub layer. In the second chapter, we found that in a fragmented landscape with the higher road network, Mussununga has a higher chance to be invaded by Acacia. Shape index had a negative effect in Acacia invasion, while the length of roads, Mussununga size, Mussununga perimeter, length of highways and landscape conductance had a positive effect. Finally, in the third chapter, we found A. mangium has a large suitable area in all scenarios, while A auriculiformis is confined to a relatively small region of 13,083 km 2 (± 3.39 SD). In the low greenhouse gas emissions scenario (RCP 2.6), the suitable area for A. mangium expanded from the current scenario of 18.4% of the Atlantic Forest to 24.0% in the year 2050, while, achieved around 44,3% of the Atlantic Forest area in the worse scenarios (RCP 8.2, in 2070). Still in the scenarios with higher climatic change, the suitable area for A. mangium overlapped around 39.3% of the potential area for restoration programs, in Atlantic Forest.
Phylogenetic structure is determined by patch size in rock outcrop vegetation on an inselberg in the northern Amazon region
(Acta Amazonica, 2018-07) Villa, Pedro Manuel; Gastauer, Markus; Martins, Sebastião Venâncio; Carrión, Juan Fernando; Campos, Prímula Viana; Heringer, Gustavo; Meira-Neto, João Augusto Alves; Rodrigues, Alice Cristina
Although inselbergs from around the world are iconic ecosystems, little is known on the underlying mechanisms of community assembly, especially in their characteristic patchy outcrop vegetation. Environmental constraints are expected to cause phylogenetic clustering when ecological niches are conserved within evolutionary lineages. We tested whether vegetation patches from rock outcrops of the Piedra La Tortuga Natural Monument, in the northern Amazon region, are phylogenetically clustered, indicating that environmental filtering is the dominant driver of community assemblage therein. We classified all patches according to their size as very small (< 1 m 2 ), small (1-4 m 2 ), medium-sized (4-8 m 2 ), and large patches (8-15 m 2 ). From each class, we randomly selected 10 patches, totalizing 40 patches covering 226 m 2 . All individuals found in the 40 isolated patches were identified to the species level. We also correlated measurements of phylogenetic community structure with patch size. We found that species from patches are restricted to the clades monocots, fabids, malvids, and lamiids. We conclude that vegetation in this rock outcrop is phylogenetically clustered. Furthermore, we found that phylogenetic turnover between pairs of patches increases with patch size, which is consistent with a scenario of higher environmental stress in smaller patches. Further research is necessary to identify nurse species in inselberg vegetation, which is pivotal for conservation and restoration of this particular ecosystem.
Selaginella P. Beauv. from Minas Gerais, Brazil
(Acta Botanica Brasilica, 2016-01) Heringer, Gustavo; Valdespino, Iván A.; Salino, Alexandre
Selaginella P. Beauv. is the only genus in the family Selaginellaceae Willk. The genus is monophyletic, has a cosmopolitan distribution, contains about 750 species and can be characterized by the presence of rhizophores, leaves, a ligule, heterospory and adaxial, reniform sporangia. Twenty species were found in the study area: Selaginella alstonii, S. contigua, S. convoluta, S. decomposita, S. erectifolia, S. erythropus, S. flexuosa, S. jungermannioides, S. macrostachya, S. marginata, S. microphylla, S. muscosa, S. producta, S. sellowii, S. sematophylla, S. suavis, S. sulcata, S. tenella, S. tenuissima and S. vestiens. Two new species records for the state are presented (S. jungermannioides and S. tenella). We present descriptions of the genus and species, an identification key, the synonyms pertaining to Brazil, illustrations, and comments about the taxonomy and distribution of species in Brazil.
Seven new species of Selaginella subg. Stachygynandrum (Selaginellaceae) from Brazil and new synonyms for the genus
(PhytoKeys, 2015-06-16) Valdespino, Iván A.; Heringer, Gustavo; Salino, Alexandre; Góes-Neto, Luiz A. de Araújo; Ceballos, Jorge
We describe seven new species of Selaginella subg. Stachygynandrum (Selaginella alstonii, Selaginella blepharodella, Selaginella crinita, Selaginella mucronata, Selaginella mucugensis, Selaginella saltuicola, and Selaginella sematophylla) from Brazil and discuss their possible affinities and conservation status. Scanning electron micrographs of stem sections, leaves, and spores are provided to illustrate the new taxa. In Selaginella alstonii and Selaginella saltuicola vegetative growth from strobilus tips is reported and discussed. Four of the new species are from the Espinhaço Mountain Range associated with Campos Rupestres (montane savannah/rocky fields) vegetation. Three of these (i.e., Selaginella blepharodella, Selaginella crinita, and Selaginella mucugensis) were collected in the northern part of the range in Chapada Diamantina, state of Bahia, while Selaginella alstonii is from the southern part of the range in the state of Minas Gerais. Selaginella mucronata is found in Atlantic Rainforest vegetation in the state of Espírito Santo, whereas Selaginella saltuicola inhabits Cerrado (tropical savannah) vegetation in the state of Mato Grosso. Selaginella sematophylla is the most widely distributed of the new species and was collected in Espírito Santo, Minas Gerais, and Rio de Janeiro states in Campos Rupestres and Atlantic Rainforest vegetation. Selaginella alstonii occurs in rocky caves, Selaginella blepharodella, Selaginella crinita, Selaginella mucugensis, and Selaginella sematophylla seem adapted to seasonally dry places, living on sandy or humid soils, Selaginella mucronata occupies humid, forest understory, and Selaginella saltuicola is adapted to wet places associated with rocks or logs in waterfalls. Of the seven new species, six are considered local endemics (except for Selaginella sematophylla) because of their restricted currently known distributions to one or two localities within a single state in Brazil. Additionally, we propose new synonymy for Selaginella palmiformis (syn. = Selaginella bahiensis subsp. manausensis, ≡ Selaginella manausensis) and Selaginella vestiens (syn. = Selaginella fragillima); the last species is endemic to Brazil, recorded in the states of Goiás and Minas Gerais. Finally, based on literature discussed and this study, we conclude that the number of well-documented Brazilian Selaginella species is 61, of which 58 are native and three introduced and naturalized. These statistics are likely to change with further work on Selaginella from Brazil.