SA’s biodiversity at risk

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SA’s biodiversity at risk

Post by Klipspringer » Sat Oct 12, 2019 7:44 pm

SA’s biodiversity is at risk despite commendable conservation laws

Johannesburg - Dr Andrew Skowno started his career counting the Clanwilliam cedar, an iconic conifer tree species, found in the Cederberg mountains and nowhere else on earth.
The critically endangered species, which survived the last Ice Age, is being wiped out by climate change.

“It faces increasing pressures as temperatures rise, the environment dries out and fires become more frequent, “ explains Skowno, the lead scientist for the National Biodiversity Assessment (NBA) at the South African National Biodiversity Institute (Sanbi).

“Unfortunately, across our assessments, climate change is emerging as a more apparent threat to our species and ecosystems.”

The NBA is a landmark outlook on the increasingly fragile state of SA’s biodiversity. “We live in a dynamic period of land use change and sea use change, affecting our environment and people, set against the backdrop of dramatic global climate change. To navigate this, we need good information,” says Skowno of the NBA’s importance.

The four-year project was undertaken by 480 scientists from 90 organisations. It reveals how almost half of all SA’s 1021 ecosystem types are threatened with ecological collapse and one in seven of the 23 312 indigenous species assessed are threatened with extinction. Major pressures include habitat loss, changes to freshwater flow, overuse of some species, pollution, climate change and invasive alien species.

However, efforts to protect biodiversity “are showing promising outcomes”, as over two-thirds of ecosystem types and 63% of species assessed are represented in protected areas.

Investing in ecological infrastructure, “is as important as investing in built infrastructure” and safeguarding the delivery of services from ecosystems can support service delivery from all spheres of government,” writes Barbara Creecy, the Minister of Environment, Forestry and Fisheries, in the forward to the NBA’s 214-page synthesis report.

But the report’s authors state that while biodiversity is a national asset and a powerful contributor to inclusive growth and job creation, its protection is, at times, “cast as a hurdle” to socio-economic development.

This is “unfortunate”, the authors assert. “Every decision taken, whether by the government or individuals, affects the future of biodiversity. By investing in the restoration, protection and management of our biodiversity assets and ecological infrastructure, we enhance social and economic development and contribute to human well-being.”

Skowno adds: “We may not ever know we’ve lost something crucial because we never discovered its particular value. There’s that old argument, that the cure for cancer becomes extinct before we’ve even noticed it ... And nature, too, has its own intrinsic value.”

Biodiversity provides jobs

Jobs directly related to biodiversity total more than 418000 “and this is likely an underestimate”, says the report, detailing how this is comparable to the mining sector. For each job dedicated to protecting biodiversity there are five that depend directly on using biodiversity.

Continued investment in managing and conserving biodiversity is essential. “In a context where employment in traditional sectors such as manufacturing and agriculture is declining, biodiversity-related employment is based on a renewable resource, that, if appropriately managed, can provide the foundation for long-term economic activity and sustainable growth,” says the report.

Healthy ecosystems = water security

Rivers, wetlands and their catchment areas are crucial ecological infrastructure for water security, often complementing built infrastructure, but their benefits are compromised by their poor ecological condition.

This is from the over-extraction of water, pollution from wastewater treatment works, agriculture and stormwater (nutrients, plastics and toxins), invasive alien species, habitat loss and degradation and climate change.

“Pollution of inland aquatic ecosystems from acid mine drainage, mining, industrial and urban wastewater, as well as agricultural return flows, negatively impact water quality. Protection and rehabilitation should be prioritised; particularly the rehabilitation of our malfunctioning wastewater treatment works and the management and eradication of invasive plants in Strategic Water Source Areas (SWSAs).”

SWSAs make up just 10% of SA’s land area but deliver 50% of all surface water, supporting half the population and nearly two-thirds of the economy. Only 12% of their extent fall within protected areas.

Climate change is impacting on people, ecosystems

The impacts are evident “across all realms and within most species groups” but biodiversity provides resilience against the worst effects of climate change.

“Restoring ecosystems and maintaining them in a good ecological condition means they are better able to support natural adaptation and mitigation processes, offering increased protection to human communities and reducing the economic burden of future climate disasters.”

Shifting migration times for species (Palaearctic migrant birds), declines in range sizes (Protea canary) and large-scale plant die-offs (Clanwilliam cedar) are being observed. Significant reductions in 70 species of amphibians’ range sizes are probable early impacts, too, according to the report.

Southern Africa has recorded nearly 500 climatic disasters impacting 140 million people in the past 40 years. Temperature increases of more than 1ºC in the past 50 years have been accompanied by the intensification of extreme events - droughts, heavy rainfall, coastal storm surges, strong winds and wildfires.

“Increases of 2-4°C are predicted for southern Africa by 2050, and confidence is therefore high that climate change will have dramatically escalating impacts on South Africa over the coming decades.”

Impacts are “triggering large-scale spatial, temporal and compositional shifts in biodiversity. Species’ population-level changes are being translated into community-level reorganisations, and even regime shifts (bush encroachment), which can impair ecological function”. Over the last few decades these changes have been noted in SA ecosystems from estuaries, coral communities, open savannas to montane streams, exerting pressure either directly or indirectly on all species within these habitats.

“Climate change is a key threat to sub-Antarctic ecosystems; mean annual air and sea temperatures have increased at twice the mean global rate at our Prince Edward Islands.”

It will not only increase the risks to estuary ecosystems under significant pressure at present “but also to the human communities and associated infrastructure and property surrounding them”.

Climate change, say the authors, is “widely considered as a multiplier of other pressures on biodiversity, both exacerbating the effects of these pressures and altering the frequency, intensity and timing of events.

“Many of these shifts are predicted to benefit the survival of invasive species over native species and increase the outbreak potential and spread of disease.”

Small high-value ecosystem types provide disproportionate benefits

Indigenous forests, inland wetlands, lakes, estuaries, mangroves, dunes, beaches, rocky shores, kelp forests, reef seamounts, pinnacles and islands take up less than 5% of the country’s territory but are “responsible for a disproportionally large number of benefits”, such as water purification, nutrient recycling, carbon storage, storm protection, recreation and harvesting of food directly from nature.

“They should be prioritised for planning, management, and protection and restoration efforts as such efforts will provide a high return on investment, both for biodiversity conservation and for benefits to society.” These ecosystem types are particularly vulnerable to climate change.

Benefits from fishing at risk

Estuarine and marine ecosystems provide food and livelihoods yet many fish stocks are overexploited and many fish species are threatened.

“The benefits provided by fishing, which include providing food for people and fodder for intensive animal farming, as well as thousands of jobs, are at risk from poaching, overfishing, unselective fishing practices (gill netting, trawling), habitat degradation (mining) and declining conditions of fish nursery areas (in estuaries).

“Fisheries stock status is not assessed for 90% of the more than 770 harvested marine taxa, and of those 10% that have been assessed, more than a third are overexploited or collapsed,” says the report.

Estuaries, inland wetland ecosystems highly threatened

About 99% of estuarine area and 88% of wetland area is threatened - less than 2% of their extent is in the well-protected category. They are essential for water security, food security, tourism and recreation and natural disaster risk reduction. “They are also important havens for many endemic species that are threatened. Restoring and protecting these ecosystems will secure the key benefits from these ecosystems and deliver a large return on investment.”

Freshwater fishes are the most threatened of all species groups that have been fully assessed with one in three threatened with extinction. Half of these species are found nowhere else on Earth.

Protected areas safeguard many species

They are generally providing good protection for species, with the proportion of threatened species increasing over the past 30 years for most taxonomic groups assessed.

But when considering threatened species alone, more than 85% of threatened birds, plants, freshwater fishes, amphibians, mammals and butterflies are under protected,” and continued expansion is needed.

60% of SA’s coastal ecosystem types are threatened

Pressures on coastal biodiversity include unsustainable harvesting of species, inappropriate infrastructure development, mining, decreased freshwater flow into the sea from rivers and pollution. “Proportionately, the rate of habitat loss in the coastal zone is twice that for the rest of the country,” says Linda Harris, of Nelson Mandela University, who led the coastal assessment. Some beaches are being eroded, putting one of SA’s most popular recreational activities at risk.

Invaders threaten biodiversity, well-being

Over 100 alien species have a severe impact on biodiversity and in some cases, on human well-being, impacting on water and food security. Invasive trees and shrubs reduce surface water resources by 3% to 5%, and threaten up to 30% of the water supply of cities like Cape Town and Port Elizabeth. “Invasive alien plants also reduce the capacity of natural rangelands to support livestock production, threatening rural livelihoods and food production,” states the report.

What needs to be done?

While SA has good policies and legislation for biodiversity conservation, implementation challenges remain. “Strengthening compliance and enforcement comes out throughout the NBA,” Skowno says. ... s-34745670

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Re: SA’s biodiversity at risk

Post by Richprins » Sun Oct 13, 2019 8:54 am

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