- The Kashmir Valley is experiencing warmer winters and as a result the flowering period for the Sternbergia vernalis flower has shifted from mid-March to mid-February.
- Changing climatic conditions have the potential to disrupt the plant-pollinator interaction, leading to potential mismatches, hence putting plant and pollinator species at a risk of extinction.
- The irregular weather pattern has also delayed the flowering of saffron to November, when the sunshine is not adequate. About 30 percent of the flowers get aborted within the sprout because temperature conditions are not optimum.
The dazzling yellow bloom of the gul toor, has been a sight to soothe sore eyes in Kashmir. After a protracted winter where this colour is largely missing, this yellow flower, Sternbergia vernalis, becomes an important signpost for understanding flowering processes in the Kashmir Valley.
The gul toor blossom, however, is no longer a herald of joy. Lately, the sight of the blossom has become one of the surest signs that all is not well. A new study has revealed that these herbaceous flowers are blossoming a month early due to changing temperatures seen in the valley over the last four decades.
The study conducted by the University of Kashmir reports a shift in the spring flowering phenology (the study of flowering patterns and cycles which are influenced by seasonal climactic changes) of model plant species Sternbergia vernalis, in response to the changing climate in Kashmir region of the Himalayas.
A shift in the flowering cycle of gul toor
The findings of the study revealed “a significant increasing trend” of 0.038 and 0.016 degrees Celsius each year in the annual mean maximum temperature and mean minimum temperature respectively, while the diurnal temperature range (the difference between maximum and minimum temperatures in a day) increased by 0.023 degrees Celsius per year. The researchers also noted an insignificant decreasing trend in annual precipitation of −1.24 millimeters per year over the last four decades (from 1980 to 2019) in the region.
According to the study, the flowering phenology of the gul toor has significantly advanced by 11.8 days/degrees Celsius increase in maximum temperature and 27.8 days/degrees Celsius increase in minimum temperature, “indicating that the climate warming has led to substantial shifts in flowering phenology of the model plant species.”
Glacial melting and unusual weather phenomenon are manifestations of climate change, according to Anzar Khuroo, the senior assistant professor at the department of botany in University of Kashmir. “Further, the phenology (annual calendar events such leafouts, flowering, fruiting, fall for different types of plants) is directly linked to the climate. With the change in temperature and precipitation, the plants respond accordingly,” Khuroo explained.
In the backdrop of these changing climatic patterns, the department of Botany conducted the study on S. vernalis using meteorological, historical and experimental data.
“Through figures from Meteorological Department, Srinagar, we checked two variables – the maximum and minimum temperatures over the last 40 years in the Valley. It indicates that winters have lost their severity and the frequency of sub-zero temperatures is getting less. Also, over the last decade, we observed that the month of February is relatively warmer,” elaborated Khuroo.
He said, the findings correlated with the historical records extracted from the earliest specimen of S. vernalis (collected in 1980) at the KASH herbarium, and experimental data.
“We concluded that with the increase in temperature, the snow albedo (snow on the surface) melts quickly. As a result, the underground bulbs of these S. vernalis flowers get enough moisture and optimum temperature with the early snow melt. Consequently, the flowering has shifted from March 15 to mid of February,” Khuroo added.
Early flowering observed across species
Another study by the department on eight spring flowering species of Kashmir Himalayas including Prunus persica (peach), Prunus tomentosa (down cherry), Populus alba (white poplar), Populus deltoids (eastern Cottonwood), Ulmus villosa (cherry-bark elm), Ulmus wallichiana (Himalayan elm), Viburnum opulus (snowball tree) and Viburnum cotinifolium (smoketree leaved viburnum) have revealed a similar pattern of early flowering due to increasing temperatures.
The research monitored the winter dormant twigs of these species in controlled growth chambers to study the effect of different temperature regimes on the patterns of phenological shifts.
Tabassum Hassan, lead author of the study said these flowering species are also sensitive to temperature changes. “We observed the eight twig species at two variables—one when the flower opens and when the flower dries up (senescence). Our findings revealed with the increase in temperature, there was early flowering. Further, the intensity of the flower drying up was far more than that of flower opening,” she added.
Senior scientist at CSIR-Institute of Himalayan Bioresource Technology, Gaurav Zinta said that warming usually translates into early flowering but this shift has major consequences like “ecological mismatches”, when the plant-pollinator interaction is affected.
“For example, while warming leads to early flowering, pollinators like bees are not available at that time which leads to a reduction in the spread of the flowers. In terrestrial ecosystems, one crucial ecological interaction is the pollination of plants by animals, an interaction dominated mainly by insects, representing 9.5% of global food production,” Zinta explained.
He added that global warming has the potential to disrupt this mutualism, leading to potential mismatches (i.e. a failure to achieve an efficient interaction) hence putting plant and pollinator species at risk of extinction. Thus, warming can directly affect the fitness of species across their current ranges, but it can also alter their ecological interactions.
Zinta noted that the early flowering trait coincides with the frost environments thus; untimely bloom increases the chance that the flower will be exposed to frost.
He pointed out that warming has also caused a decline in the yield and quality of the temperate fruits in the north-western Himalayan regions, including Kashmir and Himachal. “This has also resulted in a shift in the range of apple cultivation to higher altitudes from low or mid-hills,” he said.
He said to prevent early flowering in plants, there is a need to reduce the rates at which the planet is warming.
“We need to reduce the emission of greenhouse gases, shift to green energy solutions, use perennial crops in agricultural, adopt more CO2 sequestration technologies and the transport system needs to be transformed (to electricity-based or other green fuels),” Zinta said.
Former dean and senior scientist at Wildlife Institute of India (WII) Dehradun Gopal Rawat said studies do show that higher altitudes show more increase in mean annual temperatures as compared to lower altitudes. However, variability in mean minimum temperatures is higher than the mean maximum temperature.
“For example, in Uttarakhand there has been a slight delay in onset of monsoon during last decade,” he said. Rawat noted that one of the major concerns in the mountains is the higher frequencies of extreme weather events such as hail storms, untimely precipitation, among others, that would affect horticulture as well as agriculture in north-western Himalayas.
“Also, the ecological consequences of early flowering can be several including low fruit/seed formation if there are no pollinators, disruption in subsequent phenophases,” he said.
Talking about the scientific solutions to early flowering, he stressed on developing and adopting new varieties which flower and mature early. “Accurate weather predictions and diffusing hailstorms using modern technology could be other possibilities,” Rawat proposed.
Saffron farming under distress
While the effects of climate change are far and wide, Kashmir’s most expensive spice, saffron (Crocus sativus) is also feeling the ill-effects of adverse weather.
India has a distinction for being the second largest producer of saffron after Iran. The best quality saffron in the country is produced in the union territory of Jammu and Kashmir. It is recognised as a Globally Important Agricultural Heritage System of India by Food and Agriculture Organization of the United Nations (FAO) and also holds a Geographical Indication tag.
However, the erratic weather observed in Kashmir from 2014 to 2017 has put the saffron farming system under great distress. “This is leading to reduction in overall production from 16.5 metric tonnes (MT) recorded in 2013 to almost 1.5 MT recorded in 2017,” according to a study by Sher-e-Kashmir, University of Agricultural Sciences and Technology of Kashmir, India.
Senior scientist at the plant biotechnology and agro-technology division at CSIR-Indian Institute of Integrative Medicine, Wajid Waheed Bhat said there are different phenological stages of saffron. He explained that the first stage begins from May 1 to June 25 (corm dormancy). During this period, saffron corms (swollen underground plant stem that stores food) apparently show neither change in the external appearance nor growth. This is followed by (flower ontogenesis) taking place from June 26 to August 25. This is a critical stage when the development of flower takes place within the corm.
After that bud sprouting takes place (from August 26 to September 30). A saffron bud is characterised with sprout initiation, root development and floral initials are distinctly visible in the vascular bundle (food and water transporter in plants).
After this stage comes flowering, when the sprout (usually composed of three sheaths) emerges from the soil surface and is influenced by weather parameters during a period of 41 days (October 1 to November 10). The longest and the most critical period includes the vegetative phase which begins from November 11 to March 31. At this stage leaves develop and provide necessary nutrients for corms.
“The irregular weather pattern experienced in the valley has delayed the flowering of saffron as we have observed in the recent years that the average temperature is more than 25 degrees Celsius in October when ideally it should come down to 20 degrees Celsius,” said Wajid, adding that as a result, the flowering gets pushed to November when the sunshine is not adequate.
“Even if the flowers are there, 30 percent of the flowers get aborted within the sprout because temperature conditions are not optimum,” he revealed.
Due to climate change, the flowering period has reduced by 20 days, according to Wajid. “It used to occur from October 1 to November 10. Subsequently, the saffron pickings have also decreased in these years. Earlier we would pick it three to four times. Nowadays we only have two pickings.” The saffron cultivation is also shifting to higher altitudes to match the temperature conditions, according to Wajid. “We now are going to up to mid hills,” he said.
Banner image: Strenbergia vernalis at the University of Kashmir’s Botanical Garden. Photo by Anzar Khuroo, Assistant Professor Department of Botany, University of Kashmir.