The Weekender | 5 Sep 2009

By Kristin Palitza

In the morning, when the first rays of the sun warm up the earth, millions of colourful flowers open up and turn their heads towards the light. It’s springtime in Namaqualand – the height of the wildflower season, when the blossoming plants turn the rolling hills of the Bokkeveld escarpment into a lush and luminous display.

Visitors from far and wide come to see this natural spectacle, but ecologists warn that climate change poses a major threat to the Namaqualand region, one of the world’s most important biodiversity hotspots. Within the next few decades, many flower species might become extinct due to changing weather patterns, they caution.

This means that Namaqualand is likely to loose the extraordinary mass-effect of flower carpets that attracts tourists from all over South Africa, Europe and even from as far as Japan. “Within the next 30 years the flower season will look a lot different,” predicts Simon Todd, independent ecological consultant and associate of the University of Cape Town’s botany department.

In the midst of the wildflower wonder lies Nieuwoudtville, the bulb capital of the world. The area around this sleepy Northern Cape village, which wakes up only once a year when the flowers come into bud, is home to 1,350 different flower species and has the highest diversity of bulbs on the globe. At least 80 of these species occur nowhere else on earth. With 50 species found on one single square metre, Nieuwoudtville has one of the highest diversities of plants ever recorded.

But many of the plants in South Africa’s biodiversity hotspot are threatened with extinction or very rare, according to the Threatened Species Programme of the South African National Biodiversity Institute (SANBI).

One in four of South Africa’s indigenous plants and 13 percent of those found in Namaqualand are of conservation concern. “We have seen a major increase in the numbers of threatened and rare flowers in the last couple of years,” explains threatened plant programme manager Domitilla Raimondo.

“There has been a 254 percent increase over the past twelve years in the number of South African plant species listed as threatened with global extinction,” she says, adding that apart from climate change, urban development, agricultural practices, overgrazing and mineral mining also pose threats to the flower diversity.

“Diversity is predicted to decrease by 40 percent by 2050, and that’s a huge amount,” confirms Todd. “Some plants will be more vulnerable than others, but what is for sure is that we will lose diversity, and the flowers will grow less dense.”

Already, only 510 of the yellow-flowering Euryops Vulgaris, which only grows in Namaqualand, are left, says Eugene Marinus, curator of the Hantam National Botanic Garden in Nieuwoudtville. And for years, botanists have failed to find another rare flower, Moraea Ciliata, which belongs to the Iris family and often flowers for only one afternoon. Only this season did they re-discover the blue-petaled plant, just outside of Nieuwoudtville, says Marinus.

The two key factors that determine if flowers bloom in spring are temperature and rain – and both have already been affected by climate change. Scientists predict a 15 percent to 20 percent decrease in rainfall and a 2.5 degree increase in temperature by 2050, says Todd.

The higher temperatures are, the faster flowers grow but the shorter they last, which means the flower season is likely to shrink with each year. Experts fear that the plants will struggle to adjust to the changing conditions.

“Climate change might happen too fast for species to be able to adapt,” reckons Bettina Knoelle, director of environmental NGO Indigo in Nieuwoudtville. “What makes matters worse is that the natural habitat that could provide the genetic resources to buffer climate change is potentially too fragmented because wide areas [of nature] have been cleared for farming.”

One of the seriously threatened veld types, where many flowers are endemic, which means that they occur nowhere else in the world, is the Renosterveld, a type of fynbos that is located around Nieuwoudtville. Already, the Renosterveld’s unique vegetation has shrunk to less than four percent, and many of the flower species that grow here are extremely rare.

“The Renosterveld is very fragile. It is full of very special bulbs that are very threatened. We are very worried and are monitoring the situation closely,” says Knoelle.

About 80 percent of Namaqualand’s rainfall, which triggers the flowers to grow and bloom, happens in the four months between May and August. “If it doesn’t rain in this period, it becomes a big problem, because the plants can’t wait,” explains Todd. “They are adapted to grow in winter, when the days are cool, so if the rains start earlier or later, they won’t flower.”

Climate change models predict that the amount of rainfall will decrease on the entire West Coast. While it will rain less often, rainfall will be heavier, with the result of frequent floods. “That’s bad for the spring flowers. The season will be more variable and we expect to have more bad years than good years,” says Todd

Botanists also fear that shifting rainfall patterns will mean more water for plants that use rain throughout the entire year, such as grasses and shrubs. As a result, their increasing numbers will suffocate the wildflowers. “Grasses will take up the space and push the flowers out because they compete with them for water and nutrients,” explains Todd.

In Namaqualand, this trend has already begin to show. “We have counted twelve invasive species of grass, which grow in some places dense like a mat and don’t let the flowers through,” confirms Marinus. He also tells of recent floods that threaten the flowers. “Two months ago, parts of the botanic garden stood knee-high in water because the river flooded,” he recalls.

In an attempt to preserve Namaqualand’s biodiversity, non-profit organisation Environmental Monitoring Group (EMG), has recently launched a conservation project on 700 hectares of land north of Nieuwoudtville. “We will re-establish and restore the natural vegetation so that this piece of land can become a model for biodiversity conservation, rehabilitation and productive land use,” explains EMG rural programme manager Noel Oettle.

“Within the next five years, we hope to show measurable improvements and plan to eventually link up this land with the greater Cederberg biodiversity corridor so that plants can migrate and create biodiversity,” he hopes.