Study offers new insights on earth's biodiversity

A critical new understanding of what drives biodiversity is the crux of a paper co-authored by Massey University scientist Professor Marti Anderson.

The paper – cover story in the latest issue of the journal Science – says that contrary to previous understandings, species turnover (or beta diversity – the time a species lasts before it becomes extinct and is replaced by other species) is similar in tropical and temperate regions when the regional species pool is taken into account. This is despite the known trend for higher overall species richness in tropical environments.

The researchers used computer simulations with real data to test a number of theories about how patterns in diversity arise. Their results suggest that the processes generating diversity may not actually differ between high and low elevations or latitudes.

“Our findings highlight the need for robust statistical methods to assess biodiversity globally, particularly in high-altitude and polar regions,” says Professor Anderson. “These areas are considered less biologically diverse than low-lying and equatorial areas, where greater stability, heat and light are thought to promote faster metabolism and more intense competitive interactions.”

Professor Anderson, a marine biologist and statistician based at the New Zealand Institute for Advanced Study at Albany, is part of an international team of quantitative ecological scientists in a working group funded by the National Centre for Ecological Analysis and Synthesis in Santa Barbara, California.

Their paper, Dis-entangling the drivers of beta diversity along latitudinal and elevational gradients, analysed changing patterns of diversity of woody plants from 197 locations spanning over 100 degrees of latitude and 2250 metres in elevation.

Professor Anderson is also lead author of another article by the group, published this year in the top-ranked journal Ecology Letters. Titled Navigating the multiple meanings of beta diversity: a roadmap for the practicing Ecologist, it was given a “Must Read” ranking by the Faculty of 1000, a website for academics which identifies and evaluates the most important articles in biology and medical research publications.

Professor Anderson’s work focuses on understanding and rigorously modelling biodiversity in ecological systems. Her research provides a theoretical underpinning for applied conservation and environmental management, and has been used to assess local New Zealand marine and estuarine ecosystems as well as large-scale global patterns of biodiversity, from fish communities in the Mediterranean Sea to the endangered birds and butterflies in Indonesian rainforests.