An ecological niche is the right set of environmental conditions under which an animal or plant species will thrive. A range of ecological niches can occur within an ecosystem. Biodiversity is the result of these niches being occupied by species that are uniquely suited to them. Desert plants, for example, are suited for dry, arid ecological niches because they have the ability to store water in their leaves.
As the world's climate undergoes change, the ability of existing species to hold on to their biogeographic niches may be altered. This has an important bearing on agriculture, as practices and crop choices that have worked well for centuries may no longer be ideal.
Factors that are altered by such changes include the availability of food and nutrients, occurrence of predators and competing species. Non-living, or abiotic factors also affect ecological niches. These include temperature, amount of available light, soil moisture, and so on.
Niche modelling
Ecologists use such information for conservation efforts as well as for future developments. However, ecological considerations may not correlate well with economic realities. To bridge these two viewpoints, ecological niche modelling can be used to examine economic feasibilities within the context of changing ecological scenarios.
Ecological niche modelling is a predictive tool for identifying new possibilities — new inhabitants for an existing habitat, or new geographical locations where a desirable plant may grow well. The modelling involves the use of computer algorithms to compare data about the environment and to make forecasts about what would be ideal for a given ecological niche.
Compare two places that are geographically apart, say the Madikeri area of Coorg in Karnataka and Gangtok in Sikkim. Both are on hilly terrain. Madikeri is at 1,200 metre above sea level and Gangtok is 1,600 metre above sea level. Average yearly rainfall is 321 cm and 349 cm, respectively. Average relative humidity at 5:30 p.m. is 76% and 83%, respectively. The similarities are many in both regions.
Where to grow
A recent paper highlights the uses that ecological niche modelling can be put to within the context of India’s geographies and agricultural economics (Amit Kumar et al., Scientific Reports, 2022). Researchers at the Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh used modelling strategies to examine the economically important spice, saffron.
Crocus sativus, the saffron plant, is propagated through underground stems called corms. It is thought to be a native of Greece, and grows best under mediterranean climate conditions. Today, Iran grows nearly 90% of the world’s saffron. The flower of the plant has three bright crimson stigmata, which are handpicked when ready and carefully dried for the commercial saffron. Besides adding flavour to food, saffron has many other uses. Ancient Indian medical texts prescribed it for disorders of the nervous system. More recent clinical trials have shown that the administration of 30 mg saffron every day had a significant anti-depressant effect (Toth et al., Planta Medica. 2019;85). Some of its chemical constituents have been shown to possess anti-cancer properties.
India produces 5% of the world’s saffron. Historically, some of the world’s most prized saffron has been grown in old lake beds of Kashmir. The temperate climate of Jammu and Kashmir is well-suited with a well-drained soil of high pH value (6.3 to 8.3), summer temperatures (when flowers develop) of around 25°C and good soil nutrient availability.
Using big data
For big data, the authors of the Indian study combined their efforts with openly available global resources. Areas of saffron cultivation in Jammu and Kashmir, Himachal Pradesh and Uttarakhand were compared with 449 locations of saffron cultivation in different parts of the world as documented by the Global Biodiversity Information Facility. Environmental data came from the WorldClim web portal, which provides data on 103 variables, ranging from solar radiation to wind speeds. Terrain data (slope, aspect and elevation) came from the Space shuttle radar topography mission (SRTM) Digital Elevation Model. Several rounds of analysis yielded a map of probable niche areas suitable for growing saffron in India.
The study identified 4,200 square kilometre of new areas suitable for saffron cultivation in places in Jammu and Kashmir, Himachal Pradesh, North Sikkim, Imphal, Manipur and Udagamandalam, Tamil Nadu. Field trials over two seasons at some of these locations obtained a saffron yield that was very close to the average national yield of 2.6 kg per hectare. Will saffron be regularly cultivated in these new areas? From an economic standpoint, the answer should certainly be in the affirmative.
(The article was written in collaboration with Sushil Chandani who works in molecular modelling. sushil chandani@gmail.com)
- An ecological niche is the right set of environmental conditions under which an animal or plant species will thrive
- Ecological niche modelling is a predictive tool for identifying new possibilities — new inhabitants for an existing habitat, or new geographical locations where a desirable plant may grow well
- Crocus sativus, the saffron plant, is propagated through underground stems called corms
- It is thought to be a native of Greece, and grows best under mediterranean climate conditions
