Sunday, April 29, 2012

Not So Pesky Ants: Their Role in Ecosystem Services

When I think of ants, my automatic reaction is annoyance.  I envision the common scenario in many college student homes: you left that half-finished bowl of Cookie Crisp out one day too long, or did not wipe up that juice you spilled on the counter while using it for a chaser in a timely fashion. Before long, you have tiny invaders all over your kitchen, and their numbers seem endless.  Although these ants are a frequent source of frustration for many of us, it is time we gave ants some credit for actually helping us out instead of blaming them for attacking our forgotten sandwich crusts.

We as humans benefit directly from many processes in nature in a variety of ways. This concept has been dubbed ‘ecosystem services’,  and can cover a range of activities from  carbon sequestration to pharmaceutical production to ecotourism.  Ecosystem services have been divided into four main categories: provisioning, supporting, regulating, and cultural.  These services have a direct effect on human well-being, allowing us to live somewhat spoiled lives because nature takes care of so many things for us automatically and without a monetary cost.
 Imagine if we had to pay bacteria for nutrient cycling? Ecosystem services are essential to our lives as we know it, and yet many go unnoticed and unappreciated by the majority of the planet’s human population. Well, it is time for ants to go unappreciated no longer. They provide the human species with a service in each of the four categories of ecological services, and deserve some positive attention for once. Ants aren't often credited with playing a role in maintaining our well-being, but I will show you how they contribute in every single aspect of the intertwined chart between nature and humans shown above.

One of the most important services provided by ants is their role in agriculture. This falls in the category of a supporting service. In 2011, Evans et al provided 
a research article that credited ants (as well as termites) with increasing wheat crop yields by 36% in dry, arid climates. This is an important service for farmers because it is a way to be more efficient without investing more money. It also allows crops to grow in areas where they can just as easily fail. The ‘green revolution’ is the term coined for the intensification of agricultural productivity in the last century. We can see that crop yields have definitely increased, but often those results are due to herbicides and other potentially harmful agents, or the use of excessive amounts of water. Ants however, allow for the crop yield to rise in a sustainable way – which is good for everyone involved. It provides a service to humans, while also helping to maintain biodiversity in these agricultural areas that normally are detrimental to biodiversity levels. Ants accomplish this amazing feat by just doing what they normally do, building tunnels in the ground. As the ants build their colonies under these dry, arid grounds, they allow for increased water infiltration and increase the amount of nitrogen in the soil. These factors allow the wheat more of the sustenance it needs to grow, and for free!And if contributing to the growth of wheat just isn’t enough, ants have also been shown to be key in agroecosystems that specialize in the production of coffee, chocolate, and wine (Chong et al 2011 and Philpott et al 2006). As it happens, those are three of my absolute favorite things in the world, so I have to give props to ants for acting as predators in these agroecosystems and protecting these much loved products from disease so they can be available for my consumption. The ants present in these ecosystems act as biological control agents, protecting the plants from insect pests and fungal pathogens, which allows for increased plant growth and reproduction. Thank you, ants.

Honey Ants eaten in Central OZ
An unexpected area of contribution that ants play a role in is the ‘provisioning’ category of ecosystem services. It may surprise you that according to Neelkamal Rastogi, ants are an “unconventional human food source” (2011). In some areas of Southeast Asia, China, South and Central America, Africa, and Australia, ants are a significant source of protein for many indigenous people. There are several species that are edible in both the adult and larvae stage of life, and in some tribes ants are prepared in such a way that they are considered a delicacy. My personal favorite method of ant consumption is mashing them up and mixing them into water to make a “pleasant sour drink”, as is done by Queensland, Australia natives (Rastogi 2011). Mmmmm…protein.

Another important ecosystem service provided by ants is in the regulation category. One might not often think of ants right off the bat when ‘disease prevention’ is mentioned, but those pesky little buggers have some tricks up their sleeve.  Like using ants as a source of nutritional protein, many native peoples across the world also traditionally used ants to treat a wide variety of diseases and afflictions.  In Africa, the mandibles of some ants were used as sutures. In India, another species was ground up and used to treat gout and joint pain. Yes, these are not the methods we use in Western medicine, but ants have also become an important source for pharmaceuticals, namely antibiotics because of their well-developed immune systems and ability to resist disease (Rastogi 2011). Pharmacological companies are continuing to investigate ants as a source of treatment to diseases such as arthritis and asthma. One more ecological service, brought to you courtesy of ants.

Ants are Awesome

And last but certainly not least, ants provide us with ecosystem services in the cultural category. Nature has many ways of contributing to our cultural growth and sustenance as humans, ranging from spiritual to aesthetic methods of service. I know some of you may feel that ants often provide a recreational disservice by invading your picnics, but let’s not forget that they contribute to the most essential human cultural service: education. Who doesn’t love watching Planet Earth, getting sucked in to the amazing footage of polar bear cubs and tiny baby sea horses. Well, ants can be pretty amazing too, and if (like me) you love dropping random facts you learn from nerdy TV shows on your friends, then this BBC video on army ants will provide a great cultural ecosystem service to you.  Enjoy.

Chong, C., L. Thompson, A. Hoffman. (2011) High diversity of ants in australian vineyards. Australian                       Journal of Entomolgy 50(1): 7-21.
Evans, T., T. Dawes, P. Ward, N. Lo. (2011) Ants and termites increase crop yield in a dry climate. Nature                 Communications 2: 262.
Philpott, S., Armbrecht, I. (2006) Biodiversity in tropical agroforests and the ecological role of ants and                   ant diversity in predatory function. Ecological Entomology 31(4): 369-377.
Rastogi, N. (2011) Provisioning services from ants: food and pharmaceuticals. Asian Myrmecology 4:                       103-120.
Sanford, M., P. Manley, D. Murphy. (2009) Effects on urban development on ant communities:                 implications for ecosystem services and management. Conservation Biology 23(1):  131- 141.

No comments:

Post a Comment