south africa’s first national status report on biological...

South Africa’s first National Status Report on Biological Invasions

BIM & FBIP 15 August 2017

This is a team effort…….

Drafting team

Bob Scholes WITS

David Richardson C I B

Christo Marais DEA

Mapula Tshangela DEA

Guy Preston DEA

Peter Lukey DEA

Wadzi Mandivenyi DEA

Bob Scholes WITS

David Richardson C I B

Christo Marais DEA

Mapula Tshangela DEA

Guy Preston DEA

Peter Lukey DEA

Wadzi Mandivenyi DEA

Reference and Advisory committee

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Why a status report?

Information from research

and monitoring

Assess the status

Inform policy and

management

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Legal requirement

The Institute [i.e. SANBI] …….. must ….. submit a report on the status of listed invasive species ……. within three years……………, and every three years thereafter

The report …. must contain a summary and assessment of:

• the status of listed invasive species; and

• the effectiveness of these regulations and control measures

Our report goes beyond the legal requirement to consider:

The status of pathways of introduction and spread

The status of alien species

The status of invaded areas

The effectiveness of control measures

The effectiveness of regulations

Appointment of SANBI/ C•I•B team

Review and collate available information

Arrange scientific symposium

Develop suite of indicators

Assign values to indicators

First full draft status report

First draft chapters

Review by stakeholders and contributing authors

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Review by experts and reference committee

Final status report

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34 papers presented at the symposium 23 papers submitted for publication 19 papers published 76 co-authors

Developing indicators for the status report

• Based on emerging international schemes

• 21 indicators for:

– Pathways

– Species

– Areas

– Control effectiveness

• 4 high-level indicators

Blackburn et al. 2011 TREE; Wilson et al. 2014 Biological Invasions

Species Alien Status—A Unified Framework

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Blackburn et al. 2014 PloS Biology; Hawkins et al. 2015 DDI

Alien Species Impact—the Environmental Impact Classification of Alien Taxa (EICAT) Scheme

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Wilson et al. in prep. 13

Indicators for pathways

Indicator Description

Number of pathways

The number of discrete pathways along which species can be introduced and dispersed

Prominence of pathways

The relative size of each pathways – minimal, moderate, major or massive

Introduction rates Number of species introduced per pathway per decade

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Release Escape Contaminant Stowaway Corridor Unaided

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Pathway of introduction

Pathways and their relative importance

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Scorecard: Pathway indicators

Indicator Value Level of confidence

Introduction pathway prominence

Minimal: 6 pathways Moderate: 10 pathways Major: 2 pathways Massive: 8 pathways Uncertain: 3 pathways

Moderate

Rate of introduction per pathway

0 species: 10 pathways < 50 species: 27 pathways > 50 species: 7 pathways

Low

Indicators for alien species

Indicator Categories

Number and status of alien species

-Present but not naturalised -Naturalised but not invasive -Invasive

Extent of alien species Species range

Abundance of alien species Rare, occasional, frequent, common, abundant

Impact of alien species -Species with minimal, minor, moderate, major and massive impacts

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2102 alien species regulated (559), or recorded in the wild, in South Africa

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Best available data from SAPIA

• Increase between 2000 and 2016 by 172, from 601 to 773 species

• Marked increases in distribution of nine species

• Spread of species under biological control has slowed down or stopped

• No detectable impact of control on other species

Source: Henderson & Wilson 2017. Changes in the composition and distribution of alien plants in South Africa: An update from the Southern African Plant Invaders Atlas Bothalia

Mapped extent of occurrence (but not abundance)

Common myna

Smallmouth bass

Mesquite

Black wattle

Number of species that currently have major impacts in South Africa

Alien species with massive impacts

Pines in fynbos

Prosopis in arid areas

Smallmouth bass in freshwater ecosystems

Wattles In mesic areas

Mediterranean mussel on rocky shores

Scorecard: Alien species indicators Indicator Value Level of confidence

Number and status of alien species

• 119 present but not naturalised • 307 naturalised but not invasive • 720 invasive

High for plants, birds Low for the rest

Extent of alien species

Plants: • 600 species in < 10 QDS • 100 species in > 100 QDS

High for plants, birds Low for the rest

Abundance of alien species

• Not estimated yet Low?

Impact of alien species

• 107 species with major or massive impact

Low

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Indicators for invaded areas

Indicator Description

Alien species richness Number of invasive alien species in a particular area

Relative alien species richness

Number of invasive alien species in a particular area as a proportion of all species (native + alien)

Relative alien species abundance

Abundance (cover, biomass or population size) of alien species as a proportion of total abundance (native + alien)

Combined impact of alien species

Impacts on key ecosystem services

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Alien plant species richness at a national scale

Alien species richness in invaded areas

Median richness for provinces (based on quarter degree grid cells)

Total richness for biomes

Alien plant species abundance in invaded areas

Versfeld et al. (1998) confirmed what is generally accepted: • Western Cape is the most invaded province (28% of area

invaded to some degree) • Mpumalanga (16%) • Northern Cape (14%) • KwaZulu-Natal (9%) These estimates, besides being crude, are more than 20 years out of date, and both the extent of invasions, and the relative dominance of species, have changed considerably since then, but there is no effective monitoring of this.

Example of area impact – reduction in mean annual runoff

Source: Le Maitre et al. 2016. Water SA

Scorecard: Invaded areas indicators


Alien species richness South Africa: 2102 species Breakdowns per biome

High for vertebrates and plants Low elsewhere

Relative alien species richness

Example 300/7000 for fynbos biome Moderate

Relative alien species abundance

No data n/a

Combined impact of alien species

Surface water runoff: 1500 – 2500 million m3/yr Livestock carrying capacity: 117 000 large livestock units Biodiversity intactness: 3%

Low

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Indicators for effectiveness of control measures

Type of indicator

Description

Inputs Money spent Planning coverage

Outputs Number of pathways, species or areas that are actively managed, as a proportion of all pathways, species or areas requiring management

Outcomes Estimated effectiveness (for each pathway, species or area) in categories (effective, partially effective, ineffective)

Pathway management Only one entry point monitored by DEA at present

Indicators of effectiveness of control measures: Pathways

• Separate measures by DAFF for agricultural pests could also reduce the rate of arrival of new environmental problems.

• Insufficient data to link the impact of these measures to the outcomes.

How many species do we manage? (number listed, number managed)

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What proportion of the population of managed species do we get to?

34 Data supplied by Andrew Wannenburgh: DEA

Indicators of effectiveness of control measures: Species

• 9 historical eradication programs – three succeeded (cats on Marion Island, two terrestrial

invertebrates) – six failed – More eradications expected over the coming decade.

• Biological control a major success - 15 species under

complete control, 19 species under substantial control.

• Management programmes have been developed for a small number of established invasive alien species, but none have been implemented. Their effectiveness therefore cannot be assessed.

• Inputs – ~ R1.5 billion/yr

• Outputs – 2.8 million ha cleared, 8 million

ha followed up (over 20 years)

• Outcomes – Localised successes

– But continued growth in populations of most species at a national scale

Area control measures

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Contributing factors to success

• Ongoing direction from a diverse project steering committee

• Rapid response team

• Focus on areas of low infestation

• Very flexible management approach

• Regular monitoring

In addition “the team was only paid following completion of a contract and after a thorough inspection of the quality of the work by the Project Manager”.

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Effectiveness of regulations

• 100s of permits issued, risk assessments completed, notices served • Low levels of compliance with requirements to submit

notifications, control plans, research information • Huge capacity constraints • Too early to gauge effectiveness

Scorecard: Intervention effectiveness indicators


Input: Money spent Input: Planning coverage

~ R2 billion/yr 4%

Moderate (underestimate) Low

Output: Proportion managed 77% of pathways 24% of species 0.36% of land

Moderate Moderate Moderate

Outcome: Management effectiveness

8% effective 58% partially effective 34% ineffective

Low Low Low

Scorecard: High-level indicators

Indicator Value Trend Level of confidence

Rate of introduction of new species per decade

70 Low




70 Low

Number of species with major impacts

107 Low




70 Low


107 Low

Percent of area experiencing major impacts

5% Low




70 Low


107 Low

Percent of area experiencing major impacts

5% Low

Effectiveness of control measures (%)

5.56% Low

Thank you

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https://abcjournal.org/index.php/ABC/issue/view/113

https://www.sanbi.org/news/sanbi-invites-comments-national-status-report-biological-invasions-sa

south africa’s first national status report on biological...

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