The Alexander von Humboldt Medal for Excellence in Vegetation Science is the highest award the IAVS can bestow on a vegetation scientist for an outstanding body of work. The Award was established in 2011 and is awarded at approximately two-year intervals.
2016: Kazue Fujiwara (Japan)
What types of forest are drier? There are many types of drier forest in the Northern Hemisphere, including warm-temperate deciduous forests and monsoon forests. These forests are unique regionally. In particular, warm-temperate deciduous forests (WTDF), especially deciduous Quercus forests, occur in Asia, Europe and eastern North America (Box & Fujiwara 2014). Quercus species differ in the WTDF, typical temperate forests (TTF) and cool-temperate forests (CTF) of different regions. WTDF are drier (on an annual basis) because winters are warmer than in temperate and cool-temperate forests; WTDF have colder winters than warm-temperate evergreen forests. Sometimes, however, the forest type is related to substrate, especially in Mediterranean areas and eastern North America. Values for the annual Moisture Index (MI = P/PET) are 0.7–1.9 for WTF in Asia, 1.0 (0.68)–1.45 in eastern North America and 0.66–1.35 in Europe. Asia has the widest range, from insular Japan to mainland China and Korea. Moisture Index values for WTDF are relatively lower than for TTF and CTF, and higher than for evergreen broad-leaved forests in Europe. Moisture Index values of WTDF in eastern North America are similar to values for warm-temperate evergreen broad-leaved forests in general. Similar tropical dry forest types include monsoon dry dipterocarp forests in Southeast Asia and dry tropical forests in Kenya. These forests are relatively simple but expand into evergreen broad-leaved forest areas as secondary forests. WTDF expand also, into typical-temperate areas as secondary forests after disturbance. Then the number of species increases in the tree and herb layers, especially in Asian forests. Another characteristic is that WTDF around lakes already show vegetation shifts under global warming. The lowest winter temperatures increase, permitting the germination and growth of evergreen broad-leaved species. This phenomenon was called “laurophyllization” (Kloetzli & Walther 1999) and can also be seen in Asia (Fujiwara & Box 1999; Fujiwara & Harada 2014), as well as in southern Europe. This is not seen at drier sites.
2015: Sandra Lavorel (France)
Linking global change impacts on biodiversity to changes in ecosystem functioning, and especially in biogeochemical cycling has stood as a Holy Grail for functional ecology for over two decades. Plant functional trait research was born to address this grand challenge.
First, there is now solid evidence that functional properties of vegetation such as community mean leaf nitrogen or fibre content or properties as simple as mean plant height control a series of processes involved in carbon and nitrogen cycling. Therefore, when environmental change modifies plant community composition as a result of plant response traits, these effects flow on to biogeochemical cycling. In 2002, we called this the response-effect framework.
Second, recent research has highlighted how plant functional traits impact biogeochemical cycling not only through plant-level processes, but also by driving interactions with other trophic levels including herbivores, soil detritivores and mineralising soil microbial communities. An audacious conceptualisation of these interactions extends the response-effect framework by portraying not only the effects of plant traits on abiotic processes, but also their effects on other biota they interact with. The consideration of not only plant traits, but also of the traits of these other organisms uncovers response – effect linkages across trophic levels. Such novel understanding increases our ability to predict biotic and biogeochemical changes along gradients of environmental change resulting from management, climate change or invasions.
Third, these insights provide a powerful means to incorporate our best ecological knowledge for quantifying ecosystem services and their variations in space and time. Trait-based models can hence be developed to map the distribution of provisioning and regulating services across landscapes, and offers great promises for scaling up to larger regions, especially by linking with remote sensing of vegetation spectral properties. Trait-based understanding of ecological tradeoffs and synergies is also powerful to highlight the opportunities and limits for the provision of multiple ecosystem services, and to ground management in sound understanding of ecological constraints.
2013: G. David Tilman (United States of America; 22 July 1949 – )
Numerous lines of evidence support a “Universal Tradeoff Hypothesis,” which posits that the same interspecific tradeoffs that lead to speciation also lead to multi-species coexistence, and cause ecosystem functioning to be strongly dependent on biodiversity. For instance, fossil records for mollusks, mammals, trees, and other taxa show that, with rare exception, ecologically similar species have coexisted for a million years or more after interchange between formerly isolated realms. Because competition theory predicts that multispecies coexistence requires that species have traits that fall on the same interspecific trade-off surface, the observed coexistence after interchange suggests that during their speciation and subsequent evolution, all species have consistently been bound to the same interspecific trade-off surface despite different phylogenetic and geographic origins. Moreover, theories of multi-species competition also predict that higher diversity leads to greater ecosystem productivity and greater stability if the competing species can coexist because of interspecific tradeoffs.
The Universal Tradeoff Hypothesis thus has the potential to provide a single unifying explanation for the evolutionary origins of biodiversity, for mechanisms of multi-species coexistence, and for ecosystem processes. In so doing, it strengthens the logical basis for the assertion that the loss of biodiversity, whether from species extinctions, community simplification, or loss of genetic variation within populations, can have serious implications for global environmental sustainability.
2011: J. Philip Grime (England; 30 April 1935 – )
This talk summarizes arguments and evidence that address an old conundrum in plant ecology "How similar must two organisms be to exploit the same environment and how different to coexist?"
2012: J. Bastow Wilson (New Zealand; 10 October 1944 – 2015)
Theories have never fared well in vegetation science. The Clements/Gleason theory (for their theories were almost identical) is the basis of three major ecological concepts: (1) Environmental filtering: its operation is, as Warming said, "trivial", though it has always been documented and continues to be, with a few brave attempts to find deeper meanings. (2) Switches: they seem likely to be pervasive in natural communities, but evidence for them is sparse. (3) Assembly rules (present in Clements/Gleason theory only as a single aside by Clements): these are essentially micro- scale switches; evidence for them is easy to obtain, but valid evidence much less easy. The elephant in the room is C-S-R theory, testable but hardly tested.
2010: John Rodwell (England; 3 July 1946 – )
The UK National Vegetation Classification has made a great difference to the way in which all manner of environmental professionals do business with the natural world, as well as illuminating the spectrum of scepticism, uncertainty and trust with which practitioners and customers variously regard science. Results from some of its many applications also reveal attitudes and practices that subvert the benefits of ecological research. On the one hand, spurious notions of the ‘wild’ minimise legitimate cultural claims to relationships with place while much conservation and landscape planning works to obliterate the fuzziness and dynamism of green infrastructure and creative interactions between nature and humankind. The policy frames to which many of us now work also exert a particular twist, imposing unrealistic targets for landscape management and inflexible measures of environmental condition. For some, the ethical implications of ecological endeavour are not a legitimate part of our professional integrity, yet the notion of ecosystem services, widely welcomed, presses such moral decisions upon us – or provides an opportunity for negotiating a more imaginative relationship to the natural world. Ecology has a place in relating environmental value and condition to human well-being in ways that neither enslave the natural nor fail to liberate human resourcefulness to find its place in a sustainable world among other creatures.
2005: Hartmut Dierschke (Germany; 11 July 1937 – )
2005: Eddy van der Maarel (The Netherlands, Sweden: 23 February 1934 – )
2005: Salvador Rivas-Martínez (Spain: 16 July 1935 – )
1997: David W. Goodall (Australia: 4 April 1914 – )
1997: Wladyslaw Matuszkiewicz (Poland: 11 April 1921 – 11 October 2013)
1997: Akira Miyawaki (Japan: 29 January 1928 – )
1997: Dieter Mueller-Dombois (USA: 26 July 1925 – )
1997: Alessandro Pignatti ( Italy: 28 September 1930 – )
1988: Heinz Ellenberg (Germany: 1 August 1913 – 2 May 1997)
1988: Makoto Numata (Japan: 27 November 1917 – 30 December 2001)
1988: Victor Westhoff (The Netherlands: 12 November 1916 – 12 March 2001)