In an interesting opening, Cardinale et. al makes clear that “the vast majority of the world’s nations declared that human actions were dismantling the Earth’s ecosystems, eliminating genes, species and biological traits at an alarming rate.” Similar to Antilla’s perspective on climate change, Cardinale states that activities by humans are indeed contributing to the Earth’s degradation in several ways. Moreover, he argues that the real question we should be asking is not whether or not humans are indeed changing ecosystems, but “how such loss of biological diversity will alter the functioning of ecosystems and their ability to provide society with the goods and services needed to prosper” (59).
Biodiversity loss influences/alters the function of ecosystems and can impact the services provided by these ecosystems for our societies. Understanding this, many research projects were devoted to analyzing this phenomenon from the 1980s and primarily flourished in the past two decades. This research was, of course, met with controversy, but it played a crucial role in revealing “six consensus statements” regarding the affect of biodiversity loss on ecosystem functions. I have paraphrased them below as follows:
- Loss of biodiversity makes ecological communities less efficient in performing ecosystem functions, such as “captur[ing] biologically essential resources.]
- Biodiversity contributes to the stability of an ecosystem (60).
- Greater biodiversity loss has a type of magnifying affect on the entire ecosystem; it is “nonlinear and saturating.”
- The diversity of a community affects its productivity to a large degree.
- “Loss of diversity across trophic levels” can have a greater impact on ecosystem functions than “loss within trophic levels.”
- Functional traits lost because of a loss in biodiversity can lead to serious consequences, namely extinction, and further greatly alter ecosystem functioning.
While each consensus statement has its critics, the main point of Cardinale and his peers is that biodiversity loss is not a passive process in ecosystems. This change has far-reaching affects on the structure and function of ecosystems.
However, as also made clear in the reading, much of this is very difficult to statistically or numerically quantify in order to get “true” answers to the difficult questions being asked. It is argued though that an emerging trend indicates, “diversity loss may have as quantitatively significant an impact on ecosystem functions as other global change stressors (for example, climate change)” (61). On another note, as demonstrated in one of the experiments, “39% of experiments in crop production systems reported that plant species diversity led to greater yield of the desired crop species, whereas 61% reported reduced yield” (62).
The point is that we cannot know for sure the degree to which changes in diversity will occur, as in how serious these changes will be, but there is no question that they affect our ecosystems and the services we receive from/rely on.
The question from this point on becomes, then, how are we to successfully and fairly implement policy measures that do not hinder us as consumers while adequately protecting biodiversity and our ecosystems without precisely knowing all the facts? The authors tell us to take “caution against making sweeping statements that biodiversity always brings benefits to society,” especially since many of these experiments, if not all, were done on significantly smaller scales than that of our ecosystem (63).
There remains much work to be done in order to make this research more reliable, accurate, and quantifiable, but it did a successful job in exposing the serious environmental issues taking place.
Where do you think further research regarding the “fundamental ecological processes that link biodiversity, ecosystem functions and services” should be headed and will we ever be able to bring all this knowledge together to take the correct steps in dealing with diversity loss (66)?
If you are interested, then take a quick look here at what the World Wildlife Foundation has to say about the impact of biodiversity loss and how it quantifies the value of our ecosystem services here!