Strategies for biodiversity conservation

Transcription

1 Institute of Earth Systems University of Malta Strategies for biodiversity conservation Louis F. Cassar PhD Elisabeth Conrad PhD

2 The conservation imperative: perspective Biodiversity hotspot High endemism High threat Growing human population a Mediterranean Large & pervasive anthropogenic pressures Significant negative impacts on habitats/biota Are we undermining crucial ecosystem services & the resilience of social-ecological systems?

3 Conservation strategies Ex-situ Relocation Zoos/botanical gardens Captive breeding Genebanks/seedbanks Cryogenic facilities Useful but limited back-up or last resort: isolation from natural habitat context

4 Conservation strategies In-situ Conservation within agro-ecosystems Habitat protection (encompassing species) IUCN (World Conservation Union) designations UNESCO European Union State/region

5 Protected areas: economic & social gains Address root conservation issue: habitat integrity Umbrella protection Key to revenue generation for conservation efforts Strong link with tourism/local development Long-term investment Multi-faceted nature allows for multi-functionality Allow for conservation of both wild & cultivated biodiversity: often compatible

6 Click icon to add picture Category Type I Strict nature reserve/wilderness area Protected areas: the status quo II National park III National monument IV Habitat/species management area V Protected landscape/seascape

7 Protected areas: evaluation

8 Protected areas: persistent challenges Management effectiveness of individual PAs Biogeographical factors Lack of formal management Resource limitations (human & financial) Management & strategic planning limitations Enforcement issues External pressures & threats Conflict issues Inadequate monitoring/feedback

9 Resilience: capacity of a system to continually change and adapt yet remain within critical thresholds Protected areas: persistent challenges Coping with global environmental change Changes in physical conditions within PAs Changes in habitats/species Adaptive capacities Addressing risk & vulnerability Sustaining economic & social well-being

10 Protected areas: persistent challenges Integration & holistic management of heritage Various designation schemes Vary in scope & extent of conservation vision Need to extend conservation beyond PA boundaries

11 Why connectivity & restoration? To provide an effective medium for the conservation of populations and communities To maintain/reinstate ecological processes within areas that have been degraded, disturbed or fragmented Connectivity, at the landscape scale, has been defined as the degree to which the landscape facilitates or impedes movement among resources patches (Taylor et al. 1993).

12 Connectivity Patches: size, shape, isolation Corridors: length, width. Mosaic: heterogeneity...

13 Functions of connecting habitats Pathway for movement of biota Habitat for flora & fauna Filters/barriers to movement of certain species Sources & sinks for environmental & biotic effects

14 Addressing fragmentation Fragmentation both process & effect Components: Overall loss of habitat Reduction in size of remaining habitats Increased isolation of remaining habitats Increased edge effects

15 Achieving landscape connectivity Two strategies: A. Managing whole landscape mosaic to promote movement & ensuring population continuity B. Managing specific habitats within the landscape

16 Click icon to add picture Strategy planning

17 Design of linkage varies by species or group of species Birds Large mammals Small mammals

18 Linkages At least 3 spatial scales: Local scale: 1 km Landscape scale: 1-10s km Regional/biogeographic scale: s km

19 Local scale Landscape scale Biogeographic scale

20 Restoration flavours Reclamation: process of repairing damaged biotopes Restoration: attempt to replicate what existed in the biotope prior disturbance Rehabilitation: attempt to put back much of what existed in biotope prior disturbance, but not everything

21 Restoration flavours Replacement: no attempt made to restore what was lost replacement of original biotope Recovery or neglect: allow nature to take its course much depends upon natural processes of seed dispersal & germination, natural dispersal of fauna Enhancement: activity designed to improve the biotope, even if change is relatively minimal

22 Basic steps for restoring a biotope 1. Set a goal 2. Determine a strategy and methods 3. Remove/control the source of degradation 4. Restore elements of the physical environment 5. Restore/reinstate the biota 6. Be patient restoration takes time

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24 Conservation value appraisal criteria (CoVAC) 1. Rarity Endemism Irreplaceability Distinctiveness Extent Naturalness Presence of Red Data Book species, and/or of species deemed rare, scarce and/or endangered. Presence of endemic forms. Presence of locally important ecological resources such as species, assemblages and biotope-types, which may be of value both ecologically and culturally, such as Ceratonia siliqua. Presence of species of biogeographic importance, as identified on the basis of the Palaearctic Habitats Classification, such as Periploca angustifolia. Presence of areas supporting semi-natural and/or natural assemblages of 1500m2 or more. Presence of areas which have been least subjected to disturbance, characterized by the absence of species of early seral stages of a secondary succession ( late-pioneer secondary seral stages ) and other pioneer elements.

25 Conservation value appraisal criteria (CoVAC) 2. Regeneration Presence of areas where either a) natural regeneration is occurring or, b) there is the potential for such regeneration and/or restoration to take place. Diversity & richness Connectivity Protection status Habitat loss Displacement Fragmentation Presence of areas characterized by species and habitat diversity. Presence of wildlife corridors or stepping stones. Presence of areas legally protected under Maltese/EU legislation. Presence of evidence of large-scale destruction of habitat. Presence of alien/invasive species, occupying niche space which would otherwise be occupied by indigenous species. Presence of evidence of local and medium-scale landscape fragmentation.

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28 Conservation value appraisal criteria (Cassar 2005)

29 10 desirable criteria given a weight of +1 3 undesirable criteria each allocated a value of -1. simplest approach possible, i.e., additive (Morse et al., 2001). Thus: EQ = i 13 i 1 = = ± c Q i i Where: EQ = ecological quality for the polygon based on criteria (i) from 1 to 13 ci = coefficient (+1 or -1)

30 Identification of sites of high ecological value (expert-driven)

31 Linear linkages across sheer sea-cliffs & escarpments Case study: Gozo Hotspots and surrounding landscapes Abandoned agricultural land for restoration Linear linkages (habitat corridors) along valley systems Stepping stones and habitat mosaics across agricultural landscapes

32 Conservation strategies: conclusions Necessity of integrated holistic conservation Range of linked strategies needed Multifunctional protected areas Effectively managed To safeguard both wild & cultivated biodiversity Connected within a regional system Supported by ex-situ strategies, as necessary To ensure long-term resilience of social-ecological systems

33 Thank you Grazie