Biodiversity, species and wildlife

 

Biodiversity is the web of life. Let's consider that again Biodiversity is the web of life

Some people dislike the term biodiversity; newsreaders, councillors and planners find it's multi-syllables a little surprising to pronounce. A complex word for a concept imbued with complexity, it does require some effort to understand. Biodiversity is found in ancient managed habitats: grasslands such as Kingston Cemetery Fungi, rare fungi, even rarer fungi heaths, chalk downs, Seething Wells woods, and brownfield sites. The older the habitat the more diverse will be the biodiversity. The greater the area the more complex the biodiversity. The less polluted the richer the biodiversity.

Biodiversity is the sum total of insects, fungi, plants, found in a habitat, or mosaic of habitats. There are various ways of classifying habitats such as the  JNCC Phase 1 habitat survey. Using these and other methods we can quantify the potential for a  biodiverse invertebrate communities using an Invertebrate Scoring Index as expounded in this post Amazon Land and:

In 2014 when- we were working on the same page - seven of us met at Tolworth Court Farm to survey some ancient hedgerows. We used a standard methodology, as well as recording sheets provided to us during a training session at the Lower Moles office (Horton Country Park). This required a qualitative analysis of the hedgerow: measurements of height, length, depth, canopy cover, species, evidence of nutrient enrichment, management, presence or absence of features including banks, fencing or 'nodes'. hedge-survey

These hedgerows were considered sufficiently important to be granted funds under the Hedgerow Incentive Scheme in 1993, which ran for 8 years. In 2001 the Council entered into 10 year Countryside Stewardship Scheme (CSS) Agreement, when this finished in 2010 the site became incorporated into the Higher Level Stewardship (HLS) scheme for the land in RBK ownership  that runs from TCF all the way to Rose Walk at Berrylands. The CSS was approved for the purpose of maintaining the fields for hay meadows and restoring and maintaining the hedgerow system, which is rich in biodiversity. Brown hairstreak and Butterfly Conservation survey 

One of biggest issues with any kind of development is fragmentation, breaking up scale and connectivity, it is also edge effect, predators such as cats, light pollution and other pollutants including pesticides. Light spillage for one  is damaging for all receptors in the natural world, especially insects and even vegetation. In areas affected by light pollution, bats can emerge late in the evening. This means that the dusk peak time for insects may have passed and our urban bat populations may be feeding at a suboptimal time. 

We are learning more about the ‘densification’ thresholds for urban ecosystem function and the response of nocturnal mammals. In a study (Hale 2012), common pipistrelle activity exhibited a relationship with the area of built land-cover, much reduced beyond the threshold of ~60% built surface, implying the existence of a threshold or tipping point, of which light and light pollution played a part. Until that urban fabric is softened or greened it will never be biodiverse. It will only have species and  wildlife.

So new habitats or small areas of habitat are not biodiverse and are not biodiversity. These may be good for wildlife or species, not biodiversity. There is no habitat, no plant community, no geomorphology, no hydrology, no complexity, no area, no web of life. There might be an component of each. Grass verges may have a hydrological function and retain water allowing some infiltration and assist towards flood prevention see here: SuDs but see here loss-of grass verges in Kingston 

Long grass deters walkers preventing soil compaction; nectar and pollen is a bonus in areas left unmown for opportunistic species. But it does not create biodiversity especially where the two dominant grass species are dog faeces enriched Yorkshire fog and wall barley; the next patch of grass is 500m distant; and glyphosate is  is the main gardening tool in council owned  communal areas. Any species assisted will be short-lived. It is a holistic approach, an overarching stewardship that is required.

People often focus on wide ranging common generalist animals such as badgers, which use most habitats. They are charismatic but can exist anywhere if we prevent over development. For me it would be yellow-meadow ants, who are the real habitat engineers. As we look at different taxa we can see the complexity of relationships; botanically nettles and brambles rank as low priority, but they may be a higher priority as a resource for nectar, or as a structural resource for nesting birds. Elements may be needed for an insect life cycle, such as old deadwood, which in turn is required as a prey species for a bird or slow worm. If an element is missing, the life cycle fails, and the species is lost.This is the problem with habitat creation, fragmented grass verges, half-hearted regimes.

Where new habitat is created in an inappropriate place, such as in between two abutting hedges where it is  shaded, then that new habitat will fail to thrive. If the existing habitat has not been surveyed beforehand, it will not trigger desk study information indicating former landfill use (common near urban riverbanks). This means the land is contaminated and will never be biodiverse. It will never create a food web or supply food for higher taxa such as slow worms. It is barren for a reason. If a new habitat is created where there is already an exisiting habitat, this could be biodiversity destruction.

Biodiversity is not the same as resource conservation such as soil, water, landscape, or food security; and while we should not ignore larger species, in general we do not have to worry too much as they are adaptable, flexible, and if anything thriving in urban areas, when we don't cut off their alleyways for movement to foraging areas or force them onto the road; or close down multiple setts for housing infrastructure (photos below taken from Cumberland house). Wildlife or single - species that people often treasure locally and focus on can be a poor measure for biodiversity.

Biodiversity is what we had. It is not created from a packet of seeds (that is habitat creation). If it happens in the context of an actual decrease in habitat area and a decrease in habitat complexity, that is called greenwash. If it occurs more regularly, then it is fast  becoming a smokescreen. If these dialogues converge from a number of media sources, then, this is politics.

See an exellent blog on a similar thread on whether or not it is important to stick to native plants in wildflower meadows here naturanaute.com by Sophie Leguil