Despite the importance of seed banks, knowledge about their formation and the extent to which they can recover after severe perturbation remains scarce. Olano et al. experimentally remove the seed bank from plots in an undisturbed semi-arid Mediterranean community and monitor its recovery over 3 years. They find that seed rain at small scales and secondary dispersal from intact banks in the vicinity replenish the seed bank within less than 2 years. The results show that soil seed bank genesis and recovery can be extremely rapid processes even under the limiting and stressful conditions of a semi-arid gypsum environment.

Much of plant biomass is in roots but we know much less about root properties that affect decomposition rates than we do about above-ground tissues. Aulen and Shipley measure decomposition rates of 17 species of trees and herbs using intact soil cores in the field and relate the differences to root chemical and morphological properties. They find that initial root traits account for 75 % of variation in interspecific decomposition rates, and may thus provide a relatively simple way of assessing root turnover.

Carolyn Fry, Sue Seddon and Gail Vines’ The last great plant hunt (2011, published by Kew Publishing at £25.00 in hardback) is difficult to categorise. Certainly, The Last Great Plant Hunt [hereafter referred to as LGPH] is an unashamed advertisement for – and celebration of – the admirably optimistic and forward-looking achievement that is the UK-based Millennium Seed Bank (MSB), and is written by a trio who have/had strong connections with the Royal Botanic Gardens (Kew, UK) that manages the facility at Wakehurst Place in Sussex (UK). But it is much more than that.

LGPH tells the story of Kew’s MSB – the “most biodiverse building on earth” (p. 93) – whose mission in storing seeds and understanding how to germinate them aims to “provide an insurance policy against imminent and future plant extinctions and to reverse the ongoing degradation of biodiversity by helping communities cultivate plants rather than exploit wild stocks” (p. 34). And it is doing that job rather well. In 2009 the MSB had secured seed from 10% (24,200 spp.) of the world’s flora, 14 months ahead of schedule (!), and under budget(!!). [Although the wisdom in 2007 of placing the billionth seed in the hands of a politician (p. 41) is questionable.] Currently, the MSB aims to have banked 25% of the world’s plant spp (angiosperms and gymnosperms in this context) by 2020; surely, a desperate race against time for the 100,000 spp. that are estimated to be currently facing extinction (p. 76).

Although much of the collected seed is stored safely in the chilled depths of the UK’s Sussex countryside, those carefully catalogued huddled masses have travelled there from every continent, like refugees from some global catastrophe. Accordingly, we have plant profiles of the Red Data-listed Tsodilo daisy of Botswana, ‘endangered in Lebanon’ Syrian bear’s breeches, and Berkshire (UK)’s critically endangered starfruit, along side insights into the Useful Plants Project (p. 152) – which helps local communities store and propagate their own particularly useful plants – operating in places as far-flung as Mali and Mexico. Accompanying the plants’ own stories are those of the people involved in their collection or use: The people dimension to the story is as important as the plants’. In some respects LGPH’s seed-collector’s tales are reminiscent of the exploits of the great plant hunters of the 18th, 19th and early 20th Centuries – notables such as Joseph Banks, Robert Fortune, Joseph Dalton Hooker, and George Forrest. But the MSB’s mission is arguably more important than those expeditions; its goal is to preserve plant biodiversity for all of humanity, rather than indulge in what may be regarded by some as the much less noble curiosity- and vanity-driven collection of new plants for the gardens of the already rich and famous. But is this really the last great plant hunt? Let’s hope not! There is still more angiosperm – and gymnosperm – diversity to find and preserve/conserve, which will only be possible with the MSB’s international partnerships with organisations in 50 countries such as South Africa, Malawi, Bulgaria, China, Australia, and Chile.

With more than 7 billion people on this planet – all of whom need to be fed – concerns over food security are firmly on the global humanitarian – if not yet the political – agenda. All too often wars, famines, and disease displace large human populations and interrupt the peaceful cultivation of crops, whilst salinisation, and desertification of soils put increasing demands on the agriculturally productive land that remains. Solutions to some of these problems may require development of new crop varieties, many of which will need to be found, or created using a mix of both traditional crop breeding and GM approaches. However, without the underlying genetic variety to work with those plans may be short-lived. So, finding and preserving the genetic diversity of certain crop spp. is an important dimension to the work of the MSB. Whilst the waste hierarchy’s 3 Rs of Reduce, Reuse, and Recycle may be the mantra of the sustainability movement, the 3 Es – Endangered, Endemic, and Economic (pp. 44/5) – is the Leitmotiv of seed conservation, and helps to direct the MSB’s seed collecting efforts. But is this subterranean seed storage in sleepy Sussex a case of putting all one’s egg in one basket? Hopefully, not; several similar depositories exist throughout the world, and the book does make a nod in their direction (e.g. probably the coolest one of them all in the Arctic archipelago of Svalbard, whose single mention is on p. 38), so the risk is somewhat spread. But I do wonder how safe such installations are – whether it be from terrorist – or extraterrestrial – attack, natural disasters (such as earthquake, tsunami…), or something as mundane as a power cut so that the freezers fail.

LGPH contains some of the most sumptuous illustrations I’ve seen in a botanical book for some time (exemplified in the 2-page spread entitled ‘Nature’s life-giving works of art’ on pp. 14-15. and the far-too-blue seeds of traveller’s palm on pp. 114/5). The book is arranged as numerous short items – typically only 2 pp. long, and which are easy to read – spread over 6 chapters covering such topics as conserving wild plants on a global scale, in search of the world’s seeds, and breathing life into degraded ecosystems. The abundant ‘amazing plant facts’, ‘amazing seed facts’, and ‘conservation facts’ scattered throughout the book help to keep it highly readable, informative, and interesting. LPGH also contains a wealth of other facts about seed biology, biodiversity, endangered floras and botanising in some of the world’s most challenging environments, and provides an interesting focus around which to base teaching sessions. And the global dimension of those short snippets of information also serves to underline the fact that the MSB is not just Kew’s story, it is everybody’s story.

In summary, The Last Great Plant Hunt is part glossy PR marketing brochure, part textbook, part blueprint for global survival, part Guinness book of seed-related facts, part adventure story, part heart-warming tale of international co-operation and optimism, part gazetteer, and part coffee-table book; and the whole is greater than the sum of its parts.

Conclusion
This account of the first 10 years of the MSB’s Project – and its ongoing Partnership – is a great story and deserves to be told. And Fry et al.’s book does it well!
Nigel Chaffey
E-mail: n.chaffey@bathspa.ac.uk

Going back almost as far you can with higher plants, we now have a remarkable use of plant-derived exudates that represents the phytopalaentological equivalent of looking for a needle in haystack. But one which has – coincidentally and inadvertently – created a new fledgling branch of botany. This is the revelation that has the fossil world in a bit of a flap: amber – a fossilised exudate from trees – has been found by Ryan McKellar et al. (Science) to house 80 million-year-old feathers and ‘protofeathers’. The mixture of prehistoric feather fragments is believed to be from both early birds and non-avian dinosaurs and is preserved in exquisite detail. Interestingly, the fascinating fossil finds come from amber samples in the Royal Tyrrell Museum in southern Alberta. But, even more interestingly – and certainly serendipitously – McKellar (an invertebrate paleontologist) was apparently looking for amber-encased wasps when he chanced upon the feathers. All of which sounds rather Crichton-esque to me. But, if you’re wondering what’s the difference between the work of Kellar and Crichton, one’s of fancy flights the other’s flights of fancy.

Some otherwise promising selections of Actinidia chinensis (kiwifruit) have fruit that are too small for successful commercialization. Wu et al. induce chromosome doubling using colchicine and measure subsequent fruit weight, size and crop load in the third year after planting and over 3 consecutive years. They find that for four female diploid genotypes the fruit of the autotetraploid regenerants are, on average, 50–60 % larger than the fruit of their respective diploid progenitors, a much bigger increase than would be produced by vine management techniques.

Taking the whole evidence-gathering issue back many hundreds of years now to an age before cookery books (cookery, a TV-obsession in the UK…). Amongst their other interesting findings, Brendan Foley et al. (Journal of Archaeological Science) bust the widespread myth that Greek amphorae were just ancient wine carriers (or urn-like containers to transport olive oil). Instead, using approximately 100 nucleotide segments of DNA from material carefully salvaged from the walls of those antique ceramic vessels, which had lain undisturbed on Greek shipwrecks for centuries, the team revealed the presence of numerous plant taxa, e.g. herbs of the Lamiaceae, juniper, terebinth (genus Pistacia – apparently, used as a wine preservative in the Middle East), pine (Pinus), Fabaceae (legume family), Zingiberaceae (ginger family), and Juglandaceae (walnut family). As the team conclude: ‘Ancient DNA investigations open new research avenues, and will allow accurate reconstruction of ancient diet, medicinal compounds, value-added products, goods brought to market, and food preservation methods’ [emphasis added by me]. Certainly, anything that lasts for 2,000 years sounds pretty well preserved to me! Going back even further – to about 6,000 years ago – Oliver Craig and co-workers have been examining ‘cooking residues’ in very old ceramic pots (PNAS 108). The team were interested in determining how quickly the introduction of farming influenced the food that communities ate. Examining lipid residues in cooking pots at about the time of the transition from hunter–gathering to more settled agricultural communities, they concluded that: ‘although changes in pottery use are immediately evident, our data challenge the popular notions that economies were completely transformed with the arrival of farming and that Neolithic pottery was exclusively associated with produce from domesticated animals and plants’. So, then as now, ‘new-fangled’ inventions – like agriculture – took time to catch on! So both this and the previous ‘CSI Herbaria’ show that everything one does leaves some sort of fingerprint (but it may take many hundreds of years for development of techniques that can detect and decipher it!). And – if you’ve got the hunger for more cooking-related items – Rachel Carmody et al.’s paper, entitled ‘Energetic consequences of thermal and nonthermal food processing’ (PNAS), and the interesting commentary thereon by Peter Lucas (PNAS) will provide some, er, food for thought for you.

It has generally been considered that the flowers of Scrophularia are mainly pollinated by wasps. Ortega-Olivencia et al. study the four species with the largest and most striking flowers in Europe and Macaronesia (S. sambucifolia, S. grandiflora, S. trifoliata and S. calliantha) and demonstrate the existence of a mixed pollination system between Hymenoptera and passerine birds. A lizard, Gallotia stehlini, is also found to interact in the pollination system of S. calliantha.

I don’t know what the rest of the world’s TV is like but the USA and the UK– and Denmark– seem obsessed with crime dramas, especially those that explore the role of forensics in catching wrong-doers. To that end there is an almost daily avalanche of CSI (Crime Scene Investigation)-themed programmes, most of which emphasise animal dimensions to the science. Well, by way of redressing the balance and extending it to other evidence-gathering areas, here is the first of an eclectic series of episodes for an unlikely-to-be-commissioned-because-most-people-don’t-think-plants-are-interesting-enough-but-what-the-heck-let’s-pitch-it-anyway series, whose rather catchy working title is ‘CSI Evidential Botanicals’.

CSI Herbaria

Leaf miners are so-called because they tunnel through the mesophyll of leaves as they consume the cholorenchymatous tissues, i.e. they mine the leaf. Their feeding activities reduce the photosynthetic area of the plants they attack and may open the plant to other invading organisms and ailments. Rightly, therefore, the herbivores are generally regarded as pests that need to be controlled. One such invasive insect inmate, the horse chestnut leaf miner (Cameraria ohridella), is currently causing major infestations of Aesculus hippocastanum (the aforesaid horse chestnut) in Europe. However, although first noted in Europe in 1986, nobody was sure where the miners had originally come from, which ignorance hampers attempts to identify their natural predators, which could be exploited as bio-control agents. Help in tracking down the miners’ ancestral home came from a very unusual source – herbarium samples collected as long ago as 1879. Not only did those samples contain preserved leaf-miner larvae, but those incarcerated insects yielded sufficient nuclear and mitochondrial DNA barcode fragments to reveal that their ultimate geographic origin was the Balkans (to discover how this was deduced you’ll have to read the paper!). As David Lees et al. (Frontiers in Ecology and the Environment) conclude: ‘this case history demonstrates that herbaria are greatly underutilized in studies of insect–plant interactions, herbivore biodiversity, and invasive species’ origins’. Underlining the importance of herbaria in providing an important temporal dimension to current studies is the case of Australian protista (and if MS Word in its finite wisdom autocorrects that to ‘protests’ I’ll be mightily irked!). Thomas Wenberg and colleagues (Current Biology) are interested in any effects that global warming might have on the distribution of macroscopic photoautotrophic protists (that’s seaweeds to the rest of us). Even though seaweeds are reasonably large there are probably no large-scale satellite records of their distribution now and several years ago. But there are herbarium records, which can be examined to assess historic distribution and abundance, which can be compared to present-day biogeographic data. Interrogating >20,000 herbarium records of macroalgae collected in Australia since the 1940s, the team identified changes in communities and geographical distribution in both the Indian and Pacific Oceans, consistent with rapid warming over the intervening 50 years. Interestingly, the team actually used records from Australia’s Virtual Herbarium (AVH), ‘an online resource that provides immediate access to the wealth of plant specimen data held by Australian herbaria’ for their study. The AVH is a publicly available database containing the location and year of collection for a substantial part of the 6 million algae, fungi and plant specimens inAustralia’s nine major state herbaria. On a less serious note, herbaria can also have a human temporal enlightenment and sociological role. Students at Canada’s University of Alberta learnt as much about botany as they did about recent North American human history when they unwrapped newspaper-swaddled plant specimens that had been donated to the university. Some of the pages of newsprint dated back to the 1950s and 1970s with stories about the Korean War, the Vietnam War, and a certain Mr Richard Nixon (whatever happened to him? Hmmm, tricky one…). Which all goes to show that botany really does broaden your mind, sometimes in unexpected ways.

Episode 2 – and more – of ‘CSI Evidential Botanicals’ to follow…

In biology, matters are rarely either good or bad; oftentimes they may be both at once (albeit usually for different organisms). Take for instance hydrogen cyanide, which is widely regarded to be rather bad since it is a potent poison that can kill most living things by ‘interfering’ (that’s a euphemism!) with respiration. However, it seems that cyanide also has a good side. Apart from its role in deterring would-be herbivores, Gavin Flematti et al. propose that it may also act as an important stimulus for the germination of some seeds (Nature Communications). The Australia-based group showed that burning plant material produces glyceronitrile (a cyanohydrin), which releases cyanide upon reaction with water. The cyanide in turn stimulates seed germination – maybe via reactive oxygen production (something else that is usually regarded as ‘bad’) – of Anigozanthos manglesii (which rejoices in the common name of kangaroo paw), and a ‘diverse range of fire-responsive species from different continents’. So, if the fire doesn’t kill you, the cyanide might just save you! German philosopher Friedrich Nietzsche’s maxim, ‘What doesn’t destroy us makes us stronger’ comes to mind. Hmm, shades of plant and superplant, maybe? Sticking with this rather incendiary topic, using ‘Bayesian Monte-Carlo–Markov-Chain procedures and calibration points from the fossil record’, Tianhua He and colleagues (New Phytologist) concluded that fire may have been a selective force in the origin of Banksia (one of Australia’s most iconic fire-adapted genera) and continued to have an impact on the direction of evolution of that taxon. Okey-dokey, so much for natural – ‘accidental’ – fires, what about ‘deliberate’ ones? Well, a more general role of anthropogenically induced fire in shaping the development of seed traits has been suggested by Susana Gómez-González and colleagues (PNAS). Studying a native annual forb, Helenium aromaticum (Asteraceae), from the Chilean matorral, they showed that fire – which is a novel, anthropogenic disturbance in that ecosystem – is shaping the evolution of seed traits such as pubescence and shape. Now, if we consider humans to be at least a bit intelligent, and they create fire usually with the assistance of tools that have been designed for that purpose, does this not now prove once-and-for-all that intelligent design and/or creation causes what others describe as evolution? Or am I missing the point here?