Context
∙ Introduction of Alien Species causes disruption to the coevolutionary balance between plants and ungulates.
What are Ungulates?
∙ Ungulates are hoofed mammals that walk on their toes. The word ungulate comes from the Latin word “unguis” , which means nail, claw or hoof.
∙ Ungulates are divided into two classes: even-toed ungulates such as deer, giraffe, antelopes, and odd-toed ungulates such as horses, zebras and rhinoceroses.
∙ They have the ability to digest cellulose as they graze on the plants.
What is the coevolutionary balance between Plants and Ungulates?
∙ Cellulose is the fibrous plant material which is hard to digest but due to presence of the specialised bacteria in the gut of ungulates they can digest cellulose.
∙ So, Plants evolve defenses to prevent herbivory and ungulates evolve ways to overcome these defences.
∙ One important plant defence mechanism is using chemicals that can be toxic on consumption.
∙ Over thousands of years, mechanisms in ungulates evolved to tolerate or detoxify these chemicals and get to the nitrogen-rich foliage.
How does Introduction of Alien Species Affect it?
∙ The introduction of exotic invasive plants disrupts this coevolutionary balance and native ungulates lose out since they do not have mechanisms to address the novel toxins in the ecosystem.
∙ Eating Lantana, for example, beyond a certain proportion of the diet can be poisonous for native Indian species.
∙ Invasive exotics outcompete native flora, diminishing the edible biomass available to native ungulates.
Concerns
∙ Native flora and fauna evolve countermeasures, and ecosystems reach a new altered equilibrium.
∙ Rapidly spreading invasives, shrinking habitats and fragmented landscapes leave ungulates facing an uphill battle.
∙ Protected area management often advocates creating grasslands from forests to increase the carrying capacity for ungulates, but this practice can exacerbate the problem as grasses have poor nutrient content compared to shrubs that herbivores eat.
Conclusion
∙ Understanding the cause-effect relations between ungulates and invasive plant dynamics is a critical management need that deserves high priority for research.
∙ It appears important to develop a new discourse that incorporates scientific evidence, stakeholder preferences and evidence-based management to develop approaches that safeguard all native species and prevent further erosion of plant biodiversity.
