The fynbos region, centred on the Western Cape, is well-known as one of the world's richest biodiversity areas and, as a result, has been extensively studied by botanists. But it still has many secrets to reveal, as the Grootbos private nature reserve near Stanford has eloquently shown.
Grootbos, a 1 750ha property in the hills overlooking Walker Bay, is on the western margin of the Agulhas Plain, an area with an extraordinarily high diversity of endemic plants and several unique terrestrial and aquatic habitats. Unfortunately, these habitats are threatened by invasive alien plants, clearing for agriculture and coastal resort development.
The reserve was acquired by the Lutzeyer family in 1991, and among their first staff appointments was a then young botanist, Sean Privett, who cut his professional teeth working on the reserve.
He undertook the first comprehensive plant survey of Grootbos over three winter months in 1997.
His plot-based study yielded 250 plant species, of which 31 had Red Data Book status. One of the species, an erica, was new to science.
Privett used his study to extrapolate that the total number of flowering species on the reserve was probably somewhere between 330 and 377.
But despite this, Grootbos was deemed to be an area of low conservation value.
Three major conservation plans have been completed for the Agulhas Plain region - two of them after Privett's survey - but none identified this reserve as being of particular conservation interest. It appeared to lack endemic species and unique habitats, had an impoverished and unremarkable Proteaceae flora - the Protea family is used in this region as a key indicator of botanical wealth - and did not boast unique or rare ecological and evolutionary processes.
However, the picture changed considerably as Heiner Lutzeyer, retired father of Grootbos proprietor Michael Lutzeyer and a keen amateur botanist, continued looking for plants after Privett's survey. Lutzeyer snr has had the advantage of being able to continue the survey in all seasons and - particularly - after fires swept parts of the property. Nevertheless, his results have been staggering.
Between 1997 and January 2009, he pushed up the number of positively-identified, herbarium-catalogued plant species on Grootbos to 753 - at least twice the number estimated from the earlier plot data. And 67 of the additional species that he found also had Red Data Book status, while another four were new to science.
The deeply significant ecological role of fire in fynbos was emphasised by the fact that Lutzeyer snr's flower tally jumped from 680 species to 750 after the huge 2006 blaze that swept this area - 70 new species as a result of what botanists term post-fire successional processes.
Privett and fellow botanists and conservation biologists Richard Cowling, Andrew Knight and Gyan Sharma use the example of Grootbos to argue that spending resources compiling lists or inventories of species that occur in important biodiversity "hotspots" - like the Agulhas Plain - is not the best way to determine priority conservation actions for these areas.
Rather, investment should be in conservation opportunities, they say in a paper about the issue that is in print for the journal Conservation Biology.
They point out there is nothing in the biophysical conditions at Grootbos that would make botanists anticipate such "astonishing results", and that it was overlooked in three spatial prioritisations for conservation.
Also, it is "highly unlikely" Grootbos is unique and that comprehensive inventories done elsewhere in fynbos - correctly, the Cape Floristic Region - will "certainly" reveal much wider species distributions and species new to science, they say.
But inventories as comprehensive as that undertaken at Grootbos will be impossible to replicate throughout the fynbos region because of limited conservation resources. Also, there is not enough time left, given the threats to habitats. Therefore, they argue, instead of undertaking long-term studies of species occurrences resources should be spent on actual conservation activities in likely areas.
"We suggest that conservation strategies in the Cape Floristic Region and other hotspots - especially in landscapes of high vulnerability - deploy limited conservation resources to areas displaying high opportunity by identifying and mapping localities where human and social capital are sufficient to kick-start actions."
- On the web, www.grootbos.com.