Every year in late August, the normally barren landscape of Namaqualand, along South Africa’s western border, is transformed into a sea of brilliantly colored daisies as far as the eye can see. The flowering in this region attracts every season to about 10,000 tourists to a part of the country that would not otherwise have many visitors. But climate change poses a threat to the flowers and to the visitor arrivals that generate income for the area.
Namaqualand Daisies (Dimorphotheca sinuata) are endemic to the Northern Cape and Western Cape provinces, and They have evolved to survive the harsh and arid climatic conditions. At the beginning of spring, the change in temperature and rainfall makes them bloom, in an example of what is called a phenological phenomenon.
Phenological phenomena – such as the timing of flowering in spring, fruit development in summer, and hibernation, hatching and mating of animals – are among the most sensitive bioindicators of climate change. Worldwide, your calendar is shifting as a result of climate change. Plants and animals go through “spring” in what used to be the “end of winter.” Simply put, the temperatures of the past winter months are higher than they were, and rising.
However, the rate of change of phenological phenomena is very particular for each species and each place. That’s why it’s important to study as many different plants and animals in as many places as possible. When we know how fast a particular species and area is changing, we can adjust our adaptation. This is especially relevant in the case of Namaqualand daisies, in order to know when to schedule tourist visits.
Compared with Europe, North America and East Asia, Few phenological studies have been carried out in Africa.. This is largely due to a lack of specific data collected on purpose for analysis.
Recent studies of the time of flowering of the jacarandas in Gauteng and of sardine migration along the east coast of South Africa have revealed the importance of traditional media and social networks as sources of data. Our team used this same strategy to analyze the changes in the rhythm of Namaqualand daisies. This is important for planning tourism and expanding our understanding of nature’s responses to climate change.
The study
We compiled 663 records of flowering dates by extracting them from a selection of diaries spanning 1935 to 2018, as well as posts on Flickr and iNaturalist. Each record received a code that collected the notification date and the observation date, and to which stage of the phenomenon it referred: first flowering, maximum flowering and end of the flowering season. The dates were then analyzed to check for changes over time. We found that all three furlongs had moved forward.
The calendar of phenological phenomena is shifting as a result of climate change
The fastest and most statistically significant advance corresponded to the dates of the first flowering, with a rate of 2.6 days per decade. The peak had been anticipated 2.1 days every 10 years. As records for the final dates of flower appearance were scarce, the trend is not statistically significant, but indicates a possible even faster advance of 2.8 days per decade.
These trends were compared with climatic data from seven meteorological stations in the Namaqualand region to understand what climatic factors trigger flowering and what are the causes of such precocity. We found that the most influential climatic factors were winter and early spring temperatures, the amount of winter precipitation, and the start date of the rainy season. They all acted together to make the plants bloom, and the changes in each of these climatic variables over the last 80 years have caused the time of flowering to come earlier.
Consequences for tourism
As the time when the flowers open occurs earlier, the timing of organized and independent tours will have to be altered to give tourists the best chance of enjoying the region in full bloom.
Unfortunately, it’s not as easy as arriving 2.1 to 2.6 days early each decade. With climate change, the timing of when flowers open is also becoming more unpredictable. Although the reserves are adapted to an earlier flowering, tourists may arrive before or after the flowers have come out. As a result, travel decisions and reservations are often left to the last minute, making planning difficult for the tourism industry.
Early flowering exposes daisies to increased risk of frost, which continues to occur in warmer weather
A phenological change is an evolutionary response to a change in climate, but it cannot take place indefinitely. Earlier flowering puts daisies at greater risk of frost (which still occurs in warmer weather), and shortening the dormancy period weakens the plants. This means more chances that the flowering season will be lost, and end in local extinction. If so, it would be a serious blow to biodiversity and a great loss for the tourism sector in the area.
What can we do?
To stop or reverse phenological changes we would need to stop or reverse climate change. The COP26 conference held in Glasgow in 2021 was an important space for countries to agree on emissions targets, but how much will be put into practice remains to be seen.
In the meantime, the flowering dates will continue to move forward as the weather continues to change. As Namaqualand daisies are wild flowers, agricultural solutions such as changing crops, moving a farm or using hybrid species do not work. You have to take advantage of the flowers while you can, and visit them while their spectacular bloom lasts. To help the tourism industry, visitors could try to make their reservations earlier and return to the area outside of the high season.
You can follow PLANETA FUTURO at Twitter, Facebook and Instagramand subscribe here to our ‘newsletter’.
#Early #South #African #daisies #set #alarm #bells