Natural forest regeneration in abandoned sugarcane fields in northeastern Brazil: floristic changes

Abstract

Surveys were undertaken to examine the floristic changes during secondary succession in three areas of 12 and three of 20-year-old secondary forests in Pernambuco State, Brazil. Two hundred and six species were identified, with 136 being found in the 12-year-old secondary forest and 161 species in the 20-year-old forest. Fabaceae and Myrtaceae were the most important families, increasing in species numbers with regeneration age. Of the 216 species, 115 were trees, 48 shrubs, 16 herbaceous plants, and 24 woody lianas, without significant differences between the two regeneration site ages. NMDS analysis revealed a formation of two floristic groups, distinguishing secondary and mature forests, with a further division within secondary forests in accordance with the time since abandonment. Similarity analysis ANOSIM confirmed the significance of the groups, which had floristic composition significant distinct (R=0.96) and 63% of dissimilarity (SIMPER). However, the sharing of 68 arboreal species between the secondary and mature forests suggests a floristic convergence. DCA analysis of the arboreal component as well as the other plant habits suggested that the separation of the subgroups is correlated with physical and chemical variables of the soils. All of these results indicate that, within the chronosequence analyzed, the velocity and direction of the floristic composition during secondary succession was influenced not only by the time of their abandonment, but also by a wide range of environmental variables.

Genetic diversity in natural populations of Hancornia speciosa Gomes: Implications for conservation of genetic resources

“…Strategies for the maintenance of forest resources have been increasingly important due to the rapid loss of natural habitats (Nascimento et al, 2012). The remaining forests are widely fragmented and mostly located in areas of monoculture and pasture (Moraes;De Mello;Toppa, 2017).…”

Floristic Composition in Chronosequence in Atlantic Rainforest Fragments

“…The literature also points out that the recovery of floristic young forests occurs slowly [32,2]. Regarding this slowness, the fact that young forests and mature forest share 43 tree species, 15 in all forests, suggests that the floristic composition of young forests tends to converge with mature forest, as well as recorded in several researches in tropical forests [2,33,34,35,31].…”

“…The small trees that occurred in all the young forests are typical species of edges and clearings of forests [29,30], being present in the young forests in sunny areas [31].…”

Does the plant economics spectrum change with secondary succession in the forest?

“…Among these forest fragments, nine were chosen: three that have regenerated for 17 years, three that have regenerated for 25 years (Nascimento et al 2012) and three that are mature forests with more than 40 years of regeneration (Trindade et al 2008) (Fig. 1), with no sign of anthropogenic activity.…”

“…The areas studied differed in the composition and abundance of species (Nascimento et al 2012(Nascimento et al , 2014 Rabelo et al 2015), such that the strategies were partially substituted along the chronosequence. The fact that species such as Albizia saman, Apeiba tibourbou, Inga ingoides, Schefflera morototoni and Casearia sylvestris have characteristics of fast resource use and are abundant in young areas, whereas others such as Pouteria gardneri, Maytenus distichophylla, Eschweilera ovata, Thyrsodium spruceanum and Ouratea castanaeifolia are conservative species that are most abundant in mature areas (Table S1), and contributed to the observed changes.…”