This recent article from BBC discusses recent findings that tree seeds are becoming increasingly smaller in / around / near areas of the Brazilian Amazon that have been heavily impacted by deforestation. The suspected reason for this relates to the disappearance of large-beaked frugivores species that had previously dispersed seeds of many of the larger seeded / fruit rainforest flora.
Below I’ve included a portion of the article, followed by a link to the full article at BBC news:
The destruction of tropical rainforests is having an even greater impact on the environment than was previously thought, a study suggests.
Scientists have found that deforestation in Brazil is causing trees to produce smaller, weaker seeds that are less likely to regenerate.
They believe this has been triggered by the loss of large birds from the forests, which have beaks big enough to feed on and disperse the seeds.
The study is published in Science.
Pedro Jordano, from the Donana Biological Station in Seville, Spain, said: “One of our major surprises was how rapidly deforestation could not only be influencing the disappearance of the fauna, but to observe how deforestation could influence the evolution of the plant traits so rapidly – within a few generations.”
Brazil’s Atlantic rainforest was once home to a vibrant array of plants and animals.The researchers found the seeds from fragmented patches of forests were significantly smaller
But with the arrival of sugar and coffee plantations in the early part of the 19th Century, it was rapidly destroyed.
Today, just 12% of the original forest remains.
To assess the impact, researchers looked at more than 9,000 seeds collected from palm trees throughout the rainforest.
Those taken from areas that had suffered heavy destruction were much smaller than seeds collected in undisturbed patches of forest.
The researchers considered a wide array of factors that might have led to the shrinkage, such as the climate, soil fertility and forest cover.
“But we found no evidence for any of those effects,” explained Prof Jordano, who carried out the research with Sao Paulo State University, in Brazil.
“The main factor was the disappearance of the large frugivore (fruit-eating) species.”