Plant science and biology in general is progressing through a new data-rich era. From molecular biology to global-scale ecology, large teams are making observations and databases that describe one or more components of activity at the chosen scale of investigation. In the 19th century, Henri Poincaré made a comment on science that is equally relevant today:
‘Science is facts. Just as houses are made of stones, so science is made of facts. But a pile of stones is not a house and a collection of facts is not necessarily science.’
Moving from large data sets to understanding requires theory, and theory often requires models to test understanding. Two papers in this issue (Ainsworth & Long, pp. 351–372; Bond et al., pp. 525–538), dealing with increases in atmospheric CO2 and world vegetation patterns, complete this full cycle, while the seed serves as a fitting biological contrast in the work of Battla & Benech-Arnold (pp. 445–452), highlighting the extremely diverse application of modelling approaches.
Ainsworth & Long bring together data from 12 large-scale Free-Air CO2 Enrichment (FACE) experiments, and 120 publications, to identify the most likely impacts of future atmospheric increases in CO2 on plants in the closest possible artificial creation of the natural environment. This Tansley review sits on top of a mass of research spawned from the general theory that increasing CO2 concentrations stimulate photosynthesis. A feature of this mass of research is the practicality of enriching CO2 concentration around the leaf, plant or plants. At its simplest, the question is addressed from squeezing a part of a leaf in a tiny cuvette, then there have been many observations on potted plants in greenhouses to the most expensive but most naturalistic approach of FACE. Read the review to see which plant responses are robust, and those which are not, in spite of the imposed practical constraints.
Bond et al. flesh out comments raised in a previous article (Lusk & Bellingham, 2004) that 25% of the Earth's vegetation is fire-maintained. Such a global view results from applying a vegetation model, based on process understanding and not simple correlations, with natural fires turned on and off. The large impact shows the almost invidious way in which the grass super biome is slowly changing world vegetation. Here, theory is tested against observations at the largest scale possible for terrestrial ecology. This approach is elaborated on in detail also in the accompanying commentary by David Bowman on pp. 341–345.
Theory and modelling approaches are integral to the research in diverse areas of plant science published in New Phytologist. The Battla & Benech-Arnold paper is one of a series from scientists interested in understanding the process of seed germination, as discussed by Bradford in a commentary on pp. 338–341, and other areas covered span a range from biochemistry (Stal, 2003; Stephens et al., 2003) and physiology (Vesk & Westoby, 2003; Wynn, 2003; Barbour & Whitehead, 2004) through to development (Tooke & Battey, 2003) and back to plant responses to increases in atmospheric CO2 (Pendall et al., 2004).
The journal's commitment to all major areas of plant science is now further enhanced in the area of theory and modelling by the appointment of our most recent editor, David Ackerly. David's interests lie in identifying functional characteristics of species and then applying theory of ecological and evolutionary processes to understand how these key functional characteristics have emerged (Ackerly, 2003; Knight & Ackerly, 2003; Ackerly, 2004a). One application of this research is that the theory that has been established can then address the potential impacts on vegetation structure and dynamics of future environmental changes. The particular vegetation of focus is the Californian chaparral. The ever likely possibility of fire raises again the question proposed by Bond et al. (2005) of what the community would be like in the absence of fire. This question parallels another of David's research interests on historical precedence in this vegetation type. Research suggests that the current chaparral, with its Mediterranean climate, was assembled from floristic elements that already possessed many of the traits that confer contemporary success, even before the advent of the Mediterranean climate (Ackerly, 2004b). In such a situation a previous theory of in situ convergent evolution seems unlikely, even though, like many unsuccessful theories, it appears very attractive.