Pinus elliottii

1. Plots with Pinus have lower forest tree density than plots lacking Pinus, and Pinus abundance decreased with increases in tree density. Forest tree density varied from 35 to 1,616 plants ha−1, and Pinus were found only in plots with tree densities below 805 plants ha−1. Plots with intermediate native tree densities were colonized only by P. elliottii and P. taeda, and plots with lower native tree densities and old fields were colonized by all three invasive species. Pinus elliottii was the species exhibiting the least invasive behavior in Rio Negro among the three invasives.

2. Slash pine was correlated with lower non-graminoid species richness and plant density in both São Paulo and Mississippi; however, these apparent negative effects were 4.6 and 11 times stronger in the non-native range of Brazil (for richness and density, respectively). Native graminoids were not present in invaded cerrado. Overhead slash pine canopy cover, pine density, and needle depth were 5.2, 3.7, and at 14 times higher, respectively, in Brazil than in Mississippi savannas, for similarly-aged pine stands. One year after implementing needle litter treatments in Brazilian cerrado and restored Mississippi savanna, plant density and non-graminoid species richness were highly suppressed, but to similar degrees in both ranges. Our results suggest that higher rates of needle deposition, associated with higher tree densities, contribute to the stronger suppression of native species in Brazil than in Mississippi.

1. Slash pine was correlated with lower non-graminoid species richness and plant density in both São Paulo and Mississippi; however, these apparent negative effects were 4.6 and 11 times stronger in the non-native range of Brazil (for richness and density, respectively). Native graminoids were not present in invaded cerrado. Overhead slash pine canopy cover, pine density, and needle depth were 5.2, 3.7, and at 14 times higher, respectively, in Brazil than in Mississippi savannas, for similarly-aged pine stands. One year after implementing needle litter treatments in Brazilian cerrado and restored Mississippi savanna, plant density and non-graminoid species richness were highly suppressed, but to similar degrees in both ranges. Our results suggest that higher rates of needle deposition, associated with higher tree densities, contribute to the stronger suppression of native species in Brazil than in Mississippi.

1. Twenty-two years after the arrival of the first invasive trees (founders), the grassland savannah has become a dense pine forest with 12,455 individuals ha−1, a basal area of 26.44 m2 ha−1, a sparse native woody understory comprised of 16 species (H' = 0.44), density of 1210 individuals ha−1 and the herbaceous layer totally absent. Invasion by Pinus elliottii has completely changed the structure of the grassland savannah and caused severe plant diversity losses. Native species surviving the invasion in the understory do not typically represent the previous composition and functional traits of the native vegetation.

Extinção local apenas nos pontos invadidos. Com a remoção da invasão é possível que as espécies nativas retornem ao local.