We inventoried two Amazonian tree communities separated by ∼∼1400 km of continuous lowland tropical forest, in an effort to understand why one was more diverse than the other. Yasuníí National Park, near the equator in eastern Ecuador, has one of the most diverse tree communities in the world. Manu National Park, at 12°° S in Peru's Madre de Dios region, is only moderately diverse by upper Amazonian standards. Following the field inventories, a database of morphological, ecological, and other traits was compiled from the taxonomic literature for 1039 species from the plots. Our goals were (1) to describe how terra firme tree communities at the two sites differed in composition, diversity, and structure; (2) to characterize the ““extra”” species responsible for the higher diversity at Yasuníí; and (3) to assess, in the light of those observations, some explanations for why forests near the equator are so diverse. Yasuníí has ∼∼1.4 times as many tree species as Manu at all three spatial scales we examined: local (1 ha), landscape (<10 000 km 2 ), and regional (<100 000 km 2 ). Yasuníí samples contain more families and genera, more individual trees per unit area, and a larger proportion of small trees. Tree species at Yasuníí have smaller stature, larger leaves, larger seeds, and smaller geographic and altitudinal ranges than those at Manu, and disproportionate increases in species diversity are observed within the Myrtaceae, Lauraceae, Melastomataceae, and several other families. Community structures were strikingly similar, with the same species ( Iriartea deltoidea , a palm) dominating both sites at identical densities. Common species at Yasuníí occur at the same densities as equally ranked species at Manu, but there are substantially more very rare species at Yasuníí. The poorer tree flora is not a nested subset of the richer tree flora, though a majority of species in each inventory do occur at the other site. Several models that offer explanations for geographic variation in tropical tree species diversity are assessed in light of these data. Most do a poor job of accounting for the patterns revealed by the inventories. We speculate that the most important factor in producing the higher diversity in Yasuníí is its rainier, aseasonal climate, and we discuss two specific rainfall-related mechanisms that appear to be supported by the data: (1) year-round water availability allowing more species to persist in the understory at Yasuníí and (2) a newly described ““mixing effect”” related to the higher stem density there.
Ecology – Ecological Society of America
Published: Nov 1, 2002
Keywords: Amazon basin ; Ecuador ; Manu National Park, Peru ; Peru ; species diversity ; tropical forests ; tropical trees ; Yasuníí National Park, Ecuador
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera