Why is biodiversity important?

Last week we discussed some anthropocentric drivers that contributes to biodiversity loss today. In recent 50 years, human have changed ecosystem more rapidly and extensively than in any comparable period of time in human history. For example (MEA, 2005), 35% of mangrove area has been lost in the last several decades, coral reefs have degraded by 20%. According to living planet index, all vertebrate species fell by 40% as a whole, with terrestrial species fell by 30%. Living planet index is based on large time-series database on vertebrate population trend indicators to track the abundance of wild animals. Yet it has the disadvantage that the selection of species, the averaging method and chosen species baseline all influence the species trend indicators (Vackar, 2011). There are currently other existing indicators (and in the future we will compare some of them in my blog), but living planet index is the most commonly adopted as a campaign tool because it is easy to understand. 

http://www.surfbirds.com/mb/Features/biodiversity-and-birds.html

But the question is, why should we care? 

According to the Millennium Ecosystem Assessment report (MEA, 2005), biodiversity is the key element in maintaining ecosystem services, including supporting services, provisioning services, regulating services and cultural services. Supporting services is fundamental services delivered by plants and microorganisms, like nutrient cycling and photosynthesis. Regulating services include climate, water, soil erosion regulation, pollination and etc. Provisioning services are mainly for human physical utilisation such as food, fibre,and fuel. Cultural services are not non-material benefits, or spiritual/aesthetic purposes of human resource utilisation. With biodiversity loss, these functions would be severely weakened. One case study would be the colony collapse disorder, which is caused the large-scale application of pesticide in agricultural land. This leads to a disorder function in the bee community with a loss of pollination function. From human perspective, it directly caused economic loss and resource waste. 

Yet is there a difference in terms of biodiversity importance of different species? Ethically there should not be any as every species has their inherit value. The inherit value of animals is raised by Arne Naess in his deep ecology movement, and was accepted in the Rio Convention on Biological Diversity 1992. However, from the ecosystem perspective, there is a difference in biodiversity importance among different species. Large mammals usually have disproportionate effects on the ecosystem, as large carnivores have a top-down regulating role in community structure, and large herbivores play as ecological engineers. Large carnivores directly regulate herbivores and mesocarnivores, and there would be a cascading effect if the top predator is lost. One example is the decline of wolf in Yellowstone leads to an increase of the mesocarnivores in Yellow stone national park and leads to the imbalance ecosystem status of the park. This is a classic ecology textbook example, yet different voices are found recently, suggesting that the restoration of the ecosystem is temporary, and wolves will lead to new changes in local biodiversity (Smith et al., 2003). In the meantime, large herbivores play the role of ecosystem engineer (Jones et al., 1994), as they regulate the availability of resources by physical state changes in biotic and abiotic materials. Hence large mammals are more ecologically important than small mammals in terms of ecological importance. Also from anthropocentric perspective, large mammals bring more economic benefits (tourism) and is frequently related to local culture (e.g. tiger is the totem of ethnic minority group in northern China). 

But even some species are more important than others, that does not mean there shall be a discrimination. Instead, conservation efforts shall be adopted in holistic management strategy and adjusted according to local conditions. In a word, biodiversity is important to human being, from fundamental surviving necessity to human well being. 

Drivers of biodiversity loss change

Biodiversity loss today is largely influenced by human activity,  by the definition of Dirzo et al (2014) it is the anthropocene defaunation, which can be compared with the five previous mass extinction.

The drivers for such biodiversity change can be multiple and complex. Vitousek (1997) summarised most common drivers land transformation and biotic additions and losses, such as grazing (Bagchi et al, 2006), fire and timber harvesting (Fisher and Wilkinson, 2005), domestic dogs (Reed and Merenlender, 2011), and agriculture (Nelner and Hood, 2011).

This picture shows that a male Yunnan Snub-nosed monkey stays alone after intense logging inside Yunnan mountains 

Domestic dog influence is an interesting example, when field researchers use camera-trap as a method to estimate population or record animal presence data near populated area, it is always easy to find domestic dogs captured by the camera traps. It is one of the most frustrated time for field researcher as originally he was expecting a hayena or leopard by the body size. Also in western China, raising domesticated Tibetan dogs is both a local tradition and business. Yet after an earthquake in 2010 and the economic recession, a large amount of these dogs were released to the wild. They now attack livestocks, wild animals and people. Researchers found the presence of wildlife residues in the stool sample of these dogs. It is a potential threat to the ecosystem balance by human action.


Using the top predators as example, 77% of the 31 large carnivores on earth decline in numbers, and 50% of these carnivores have lost half of their geographical ranges (Ripple et al., 2014). These drivers account for such decrease include habitat loss and degradation, persecution, utilization and depletion of prey, and also the future impact of human resource depletion and climate change (Ripple et al., 2014). The impact of climate change on large mammals' decline and biodiversity loss remains particularly uncertain.

In my next post, I would like to discuss with you guys why is biodiversity important, why should we care about biodiversity loss. If you are interested, prepare some answers and let us discuss.

Welcome to posts on biodiversity change to human-related pressure: drivers, solutions and case studies

Welcome to my blog, Hanbin's conservation observatory. The name of this blog comes after a wooden house in Southwestern China to be used by local researchers and me as a cozy place for birds counting. As you might see, I have an particular interest in conservation issues from interdisciplinary perspectives. Hence I will write about the response of biodiversity to global environmental change, mostly caused by human behaviour. Rockstrom is famous for his planetary boundary theory,  in which he defined nine safe operating boundaries to keep the humanity civilisation safe in Earth physical system, and one of the boundary is biodiversity loss (Rockstrom, 2009). What Rockstrom advocated is simple: to respect the rules. And here is people's response:

As a result of breaking the rule, biodiversity loss today has already exceeded ten times beyond its proposed safety boundary in 2009. Humans is a group of animal that keep breaking the rules of Earth, since human has particular difficulties in collective action, for example, NIMBYISM (Not In My Back Yard!) and Prisoner's delimma. Hardin (1968) describes this result as the failure in collective action using the metaphor of the tragedy of commons, in which scenario shepherds raised extra sheep for self-benefit and lead to the degradation of the pasture. it is the similar reasons that account for human-triggered biodiversity loss. To further elaborate this topic in my future blog writing, I want to focus more on a quantitative perspective, but also adopts anthropology, environmental ethics, international development theory and policy making. Hopefully I can present my topic here combining both science, social science and lay knowledge.

Personally I worked before with a few frontline NGOs in conservation, and computer biodiversity modelling behind the scene. I feel that, to solve conservation issues, one need to be flexible and always, act like what Bill Adams said, "to think like a human".  Human is great animal that has empathy, you just can not let it die out when you are looking at such type of pictures.

Here I also attached a short video my classmate and I made three years ago, I think it illustrates some of my personal philosophy on the relationship between biodiversity and human-related pressure. 

Hopefully we will have a nice time together!