Supporting Services

The supporting services, as their name implies, are necessary for the support and maintenance all of the: provisioning services, regulating services and the cul- tural services. The supporting services include: soil formation, photosynthesis & (net) primary productivity (NPP), nutrient cycling and pollination.

Soil

The dirt underfoot, the soil, care for it as little as we may is essential for our existence. “Soil does far more that

support farming and forestry. It stores carbon, filters water, transforms nutrients and sustains biodiversity” (Banwart,

2011). Soil is not simply disintegrated rock broken down by the physico-chemical processes of weathering. It is an ecosystem composed of diverse soil organisms such as mites, nematodes, fungi, bacteria etc. creating an aggregate of decaying biomass and microbes. Genetic analyses of soil indicate that there can be anywhere be- tween thousands to hundreds of thousands of bacteria in a gram of soil (Dance, 2008). The resulting mélange

5.3 Ecosystem Services

is an dynamic balance of mineral and organic nutrients which becomes accessible to plants after transforma- tion by microbial action (Banwart, 2011).

Bardgett and Putten (2014) write in their abstract that “Evidence is mounting that the immense diversity of

microorganisms and animals that live belowground con- tributes significantly to shaping aboveground biodiversity and the functioning of terrestrial ecosystems. Our under- standing of how this below-ground biodiversity is distrib- uted, and how it regulates the structure and functioning of terrestrial ecosystems, is rapidly growing. Evidence also points to soil biodiversity as having a key role in determin- ing the ecological and evolutionary responses of terrestrial ecosystems to current and future environmental change.”

Tragically, this essential natural capital: soil, is easi- ly destroyed by industrialized agriculture which regards soil little more than a substrate to hold crop plants. The heavy winter rains of 2013-2014 in the UK which washed away so much topsoil from fields and deposit- ed it into the seas around the British coast has already been described (Monbiot, G. (2014); as has the other soil scourge, winds which caused the 1930s US dust- bowl problem. The overuse of chemicals; pesticides and fertilizers degrades and kills the soils’ living com- ponent or biome. Evaporation of irrigated water causes salts to become concentrated in the soil. In some places around the world “soil is being lost 100 times faster than it

forms” (Banwart, 2011). Furthermore, there are substan-

tial areas where the soil is very degraded.

“One estimate valued the free services provided by the world’s soils biota (organisms) at US$1.5 trillion or more each year.” There is a very serious risk that if soils re-

main degraded and many of their inhabitants vanish we are in danger of loosing species which could increase harvests, purify the soils of toxins and provide medi- cines (Dance, 2008).

Photosynthesis and Net Primary Productivity (NPP)

Our existence on the Earth depends on one beautiful- ly simple chemical reaction. Carbon dioxide and water interact with the chlorophyll molecule and powered by sunlight create the sugar glucose and oxygen. It is writ- ten like this:

6CO2 + 6H2O + sunlight > (chlorophyll) > C6 H12 O6 + 6O2

We can also see that six molecules of CO₂ are taken up in the photosynthesis reaction which means that the process sequesters or takes up CO₂ and so helps to mit-

igate global warming. Unfortunately, we are putting too much CO₂ into the atmosphere than plants are able to use in photosynthesis. Consequently, the CO₂ content of the atmosphere now stands at 400 ppm since pre-in- dustrial times when it stood at about 280 ppm.

What is so amazing about this reaction is that we can recognize that we, along with all aerobically respir- ing organisms, are an integral part of this chemistry be- cause we depend on the oxygen produced by photosyn- thesis and plants require the carbon dioxide we expire. Furthermore, it is free – no one has to pay to breath, at least not yet!

Net primary production is “the net amount of solar

energy converted to plant organic matter through photo- synthesis” (Imhoff et al 2004). Photosynthesis is the first

step in the carbon cycle because carbon becomes fixed by plants and accumulates as quantifiable biomass. In fact “oxygenic photosynthesis is responsible for virtually all

of the biochemical production of organic matter” (Field, et

al. 1998). The marine (plankton and algae) and terres- trial (plants) are all primary producers and contribute in about equal portions to produce about 104.9 peta- grams (104,900,000,000 metric tonnes) of carbon per annum (Field, et al. 1998).

Human appropriation of net primary production (known as HANPP) on land is for a range of produce including: vegetal food, meat, milk, eggs, paper, fiber, wood for fuel and construction (see above: ecosystem provisioning services). There are various estimates for the proportion of human ‘appropriation’ including 31- 32% (with low and high estimates of 10-55%). Whatever the exact figure the proportion of appropriation is re- markable for a single species to co-opt so much of net primary production for its own use. Furthermore, our appropriation deprives other species for their needs, and changes the energy flows within food webs, the provision of ecosystem services, and also alters atmo- spheric composition and levels of biodiversity. A study by Imhoff and colleagues (2004) investigated the distri- bution of HANPP and found that there was enormous variations in the appropriation but an average of 20% ± 6% with in some regions such as western Europe and south central Asia consuming more than 70% and the lowest value in South America of about 6%. However, differences were more extreme on local levels which ranged from 0% in sparsely populated areas to over 30,000% in large urban conurbations.

5.3 Ecosystem Services

Human activities can threaten net primary produc- tion in many ways. Land which used to normally sup- port ecosystems is covered by cities, roads and other installations all reducing NPP by restricting the plant cover. For example, “China plans to move 250 million peo-

ple from farms to cities” in a vast urbanization plan with

the government goal of integrating 70 per cent of the population into cities by 2025 (Johnson, 2013). “Some 3

million hectares of high-quality arable land and some 1 million hectares of paddy land have been built on or con- verted to urban use in just over a decade” (Kong, 2014).

Agriculture changes land-use from a natural ecosystem to monoculture crops providing only scant ground cov- er, furthermore, the land may remain fallow for signifi- cant periods of time reducing NPP yields. “Altogether,

agriculture occupies about 38% of the Earth’s terrestrial surface” (Foley et al, 2011).

Climate change may also reduce NPP. The first de- cade of the new millennium has been the warmest since records began. Water is essential for photosynthesis, as the formula confirms, and consequently, water stress limits terrestrial NPP. It has been calculated by Zhao & Running (2010) that over the decade 2000-2009 there was a reduction of NPP of 0.55 petagrams (550,000,000 metric tonnes) in the southern hemisphere. We can now understand that the danger of deforestation will not merely contribute to the loss of biodiversity, but that it would also increase the danger of regional droughts which would increase as the forest area further de- creases. So far the Amazon rainforest has lost 13% of its original extent, if deforestation were to continue and remove as much as 30 to 40% of its original extent then the region might be pushed past its tipping point and into a drier climate regime. Increasing droughts would mean less water available for photosynthesis and NPP and the forest would no longer be a carbon sink but be- come a carbon emitter. Already “There has been a drying

trend in northern Amazonia since the mid-1970s …” (Mal-

hi, 2008).

Nutrient Cycling

“An adequate and balanced supply of elements necessary for life, provided through the ecological processes of nu- trient cycling, underpins all other ecosystem services. The cycles of several key nutrients have been substantially al- tered by human activities …, with important positive and negative consequences for a range of other ecosystem ser-

vices and for human well-being” (Millennium Ecosystem

Assessment, 2005).

Solar energy powers the water cycle causing evap- oration from water surfaces and also drives the winds carrying moisture inland to fall as rain. Obviously, the Sun’s energy is the basis of our existence and provides about 170 Watts/m2 _{which annually amounts to a co-}

lossal 87 Peta Watts or thereabouts (P = 1015 and so 87,000,000,000,000,000 Watts) “This total is almost

8,000 times higher than the worldwide consumption of fossil fuels and electricity during the early 1990s” (Smil,

1999). Amazingly, despite the sun’s generous supply of energy “A plant leaf converts, on average, just 1% [of-

ten less] of the energy it gets from sunlight into chemical bonds” (Van Noorden, 2011). Powered by sunlight, plant

photosynthesis is the point of interaction where carbon and water fluxes meet to create biomass (NPP) and the starting point for all food chains be they marine, freshwater or terrestrial (except those associated with deep sea vents). Although water and carbon are major constituents in the creation of biomass, it would not be possible without other essential elements namely, ni- trogen and phosphorus. Nitrogen is in plentiful supply since almost 80% of the air consists of nitrogen, how- ever, it cannot be so easily utilized by organisms and circulates through ecosystems in complex pathways. Nitrogen is converted by some algae and soil-living ni- trogen-fixing bacteria into compounds that can be used by plants and animals. When the latter die their detritus is broken down by detrivores and bacteria and eventu- ally becomes available to be taken up by the roots of plants.

The element phosphorus was first isolated from evaporated urine by the alchemist Hennig Brand in 1669 (Curtis, 1962). Phosphorus is essential for life be- cause it is a key element in the composition of both the DNA and RNA, the genetic molecules. It also plays a key role in the cell’s energy management. Phosphorus does not cycle so readily through the biosphere as the ubiquitous nitrogen and is found mainly in rock depos- its or in sea bird excrement known as guano (Ehrlich & Ehrlich, 1970). Guano is collected along the west coast of South America, in Chile and Peru and gathered in sufficient quantities to be marketed as fertilizer. In the mid-1800s it was learned how to make fertilizer from phosphate bearing rock strata. Phosphate fertilizers have played a key role in the world’s population explo- sion (Gray, 2009). The starting point for the phospho-