• 30
    Jan 2021
    Written by Prof Dez Delahay

    What is this thing called biodiversity?

    We hear the word biodiversity a lot these days, all too often in the context of its loss, but what does it actually mean? How can we measure it? And how can businesses start to embrace biodiversity as a source of competitive advantage, not something to shy away from?

    Most people understand that it is something to do with the richness of the natural world and that, in a broad sense, if a place has more different animal and plant species then it is more biodiverse than one with fewer. So that is not a bad place to start, although biodiversity actually goes much wider than this, as it encompasses all the variety of life on Earth, from genes to species, populations, communities and ecosystems.

    Genetic diversity within a species can give rise to the emergence of distinct populations that are adapted to different local conditions. This means that reducing the abundance of even a seemingly common species can risk eliminating some of these local varieties. The next level up is the unit of biodiversity that most of us are familiar with, as we can all recognise at least a few different species. Continuing to the next level, an assemblage of populations of different species that live in a particular area represents an ecological community, and when we also consider its interaction with the physical environment, then we are talking about an ecosystem. So that herd of wildebeest you see sweeping majestically across your TV screens on the latest David Attenborough blockbuster constitutes a population of that one species, but they live in a community of plains zebras, Thomson’s gazelles, many different grass species and, unfortunately for them, … lions. The collective interactions between all these species and their environment are the defining features of the Greater Serengeti grassland ecosystem. In biodiverse landscapes there may be many different communities and ecosystems.


    How to measure biodiversity

    When we measure biodiversity, we tend to focus on the diversity of species in communities and ecosystems. The number of species present is what biologists call species richness and this is the simplest measure of diversity at this scale. But this approach treats rare and common species equally. So, for example, a habitat where you have three different mammal species, but only very low numbers of two of them, would be considered equally biodiverse as one with equal proportions of all three species. But this seems intuitively wrong – surely the community with more equal proportions is actually the more diverse? In order to account for this, biologists have developed measures of biodiversity that incorporate both species richness and something called ‘evenness’. But there is another problem, which is that it can be fiendishly difficult to count the number of species in a community, particularly when you get down to the insects and other creepy crawlies, or even smaller ‘critters’. In fact, many of the smaller critters have not even been described by science yet! One estimate is that, of the 5–30 million species on the planet, only about 1.7 million have been described! No surprise, then, that we can usually only obtain an index of biodiversity rather than an absolute measure.

    As a general rule, the abundance and variety of species tends to increase the closer you move towards the equator, an observation first made over a hundred years ago by Alfred Russel Wallace, a contemporary of Charles Darwin. It stands to reason therefore that the majority of the biodiversity hotspots in the world are found in tropical regions such as the Horn of Africa, the Caribbean islands, Indo-Burma and the tropical Andes. These areas are typified by what is called high endemicity – that is, they contain high numbers of animals and plant species not found anywhere else in the world. As they contain almost half of all known species, it is no wonder that they are priority areas for conservation. These are particularly special places, but it is worth remembering that biological diversity is all around us, whatever part of the world you live in.


    What biodiversity means for business

    The diversity of life on Earth provides us with the raw materials, food, medicines, services such as climate regulation, knowledge, inspiration and everything else we need to survive and flourish. And who knows what resources and discoveries may be contained within the treasure trove of species we have yet to describe. As we degrade and remove the component parts of our ecosystems, we are eroding away at biodiversity and so undermining our own future well-being. Importantly, once a genetic variety, species, population or ecosystem becomes extinct it is gone forever – there are no second chances. That is why we need to think about biodiversity as if it were money in the bank (back in the days when they paid interest): look after it and you can live off the interest, but the more you spend, the less there is to live on, until eventually there is nothing left.

    That overdraft on our natural credit card is not just bad for nature: it is bad for business. Not to investigate and act on your biodiversity impact is the same as leaving bills unopened and pretending they are not there. Eventually, it catches up with you. By working with Nature Positive, you can get back in control, and turn nature to your advantage.

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