3. RESULTS AND OUTPUTS
3.2.2. Developing Strategic Adaptive Management Plan
The strategy draws upon a framework for adaptive management developed for managing conservation reserves with freshwater ecosystems [Figure 1,(Kingsford et al., 2011a)].
Following Nyberg (1998):
“Adaptive management is a systematic process for continually improving management policies and practices by learning from the outcomes of operational programs. Its most effective form ”active” adaptive management employs management programs that are designed to experimentally compare selected policies or practices, by evaluating alternative hypotheses about the system being managed.”
The purpose of this adaptive management strategy is to provide a more flexible tool to complement the existing “Plan of Management” that can be reviewed and updated regularly to reflect changes in our understanding of the wetland system and changes in priorities. Adaptive management is designed to illustrate the linkages between key values, objectives, management actions, and monitoring.
Vision and principles
The first step in the strategic adaptive management plan is to identify the desired future and ideal state of the Macquarie Marshes. Setting the vision and principles to inform adaptive management should be the first element, reflecting the context and values of the ecosystem (Table 4).
Table 4: The vision and the principles of the Macquarie Marshes (based on OEH’s developing adaptive management framework)
Category Descriptions
Vision The Macquarie Marshes Nature Reserve is a place where frequent floods support abundant and diverse wildlife and communities
Principles Conserve biological diversity, natural landscapes and processes to improve the health, resilience and ecological function of the Nature Reserve’s vegetation and associated fauna
Protect and enhance resources/features/customs that are valued by Aboriginal and other cultures and communities (subject to further determination involving cultural heritage stakeholders)
Apply collaborative adaptive management approaches to manage and improve knowledge about the Nature Reserve’s ecosystem
Manage the Nature Reserve with optimism and transparency, acknowledging risk and uncertainty, applying rigour and expertise
Collaborate with Aboriginal people, other landholders in the Marshes, stakeholders and communities in adaptive management activities
Figure 1: Steps in a generic Strategic Adaptive Management framework [from (Kingsford and Biggs, 2012)].
Vital attributes, determinants, threats and risks
The second element sets out to list the key ecological components of the ecosystem (i.e., vital attributes), their drivers (i.e., determinants), and stressors [
Table 5; (Ogden et al., 2005)]. Drivers are the natural forces (e.g., sea level rise) or anthropogenic (e.g., water management) that occur outside the natural system, which have large-scale influences on natural systems. Stressors are physical or chemical changes that occur within natural systems affected by drivers, causing significant changes in biological components, patterns, and relationships in natural systems.
Identified key ecological components should then form the basis for planning and objective setting. For each, the main processes ensuring resilience are then listed and the likely threats to desired state are identified and amenable to management.
Together, these should provide a compressive framework for management.
Table 5: Key biophysical values, drivers, and stressors of the Macquarie Marshes Nature Reserve
Key values Drivers Stressors
Fauna
Objectives
A key element is the formation of an explicit hierarchy of objectives, starting at high order objectives, capturing the management intent or vision down to lower order and detailed objectives of desired condition. Objectives must be clearly defined with concise and explicit links. As an adaptive management strategy, the broad objectives may be stable over time but can also change. However, the prioritisation of objectives, lower level objectives and management options, will be revised according to changes in the conditions of the ecosystems and changes in management approaches. High-level objectives capture intent while low order detailed objectives link to ‘‘on-the-ground” interpretation of desired condition. Objectives should be cross-linked for integration.
For the Macquarie Marshes Nature Reserve, four high-level objectives have been established by OEH (2012b):
Ecosystem Objectives
People Objectives
Balancing Objectives
Enabling Objectives
Below we exemplify the hierarchy structure of objectives for Ecosystem Objectives (Figures 2-8).
Figure 2: High-level objectives established for the Macquarie Marshes Nature Reserve with detailed lower level Ecosystem Objectives [from (OEH, 2012b)]
Figure 3: Floodplain dependent vegetation [from (OEH, 2012b)].
Figure 4: Waterbird [from (OEH, 2012b)].
Figure 5: Native fish [from (OEH, 2012b)].
Figure 6: Ecosystem processes and food webs [from (OEH, 2012b)].
Figure 7: Native aquatic fauna [from (OEH, 2012b)].
Figure 8: Native terrestrial fauna [from (OEH, 2012b)]
Table 6: Further objectives presently under development by New South Wales Office of Environment and Heritage (2012)
High-level objective Mid-level objectives Low-level objective Ecosystem
Objectives
Flow and inundation Surface water
Ground water
Surface water / ground water interaction
Geomorphology Erosion
Sedimentation Biodiversity
Flood dependent vegetation communities
River red gums
Common reed beds Water couch community Coolibah-black box community Native fish
Waterbirds
Ecosystem processes
Native aquatic Fauna Reptiles Frogs
Aquatic mammals Terrestrial ecosystems and biota Woodland birds
Macropods Alien species
People Objectives Aboriginal cultural heritage Partnerships with land managers Tourism, visitation and education Balancing Objectives Ramsar
Development and rehabilitation Threatened species and protected species
Enabling Objectives Reserve planning
Management and development
Figure 9 High-level People Objectives [from (OEH, 2012b)].
People Objectives
To protect cultural values, provide limited visitor experiences and build community support for the Nature Reserve
Partnerships with Marshes landholders To build partnerships with other land managers to improve conservation outcomes on the NR and adjacent lands
Tourism / visitation / education
To encourage awareness of the values of the wetland area through education, science and visitor experiences Aboriginal Cultural
Heritage To protect the Aboriginal cultural values, and historical heritage values, of the Nature Reserve
Figure 10 Lower-level People Objectives [from (OEH, 2012b)]. the NR and more broadly the entire Macquarie Marshes To encourage awareness of the values of the wetland area through education, science and visitor experiences
To protect and enhance the Aboriginal cultural values of the Nature Reserve
Protection of
Figure 11 High-level Balancing Objectives [from (OEH, 2012b)].
Balancing Objectives
To ensure reserve management, including rehabilitation, is consistent with and provides input into key policies, regulations, management regimes and legislation
Ramsar Meet obligations under Ramsar Convention, JAMBA, and CAMBA.
Development and rehabilitation
Meet obligations in undertaking development, infrastructure and rehabilitation activity
Threatened species regulation Meet obligations as relevant
Figure 12 Lower-level Balancing Objectives [from (OEH, 2012b)].
Ramsar
To manage the nature reserve to maintain the ecological character of the Ramsar site and to work cooperatively with other Ramsar managers in the Macquarie marshes and with the Australian Government to meet Australia’s obligations under the Ramsar Convention
To ensure reserve management, including rehabilitation, is consistent with and provides input into key policies, regulations, management regimes and legislation affecting the management of the Nature Reserve NR – channels, banks, levees Meet obligations, as relevant, in
Figure 13 High-level Enabling Objectives [from (OEH, 2012b)].
Enabling Objectives
To effectively plan and manage conservation activities to achieve the ecosystems, people and balancing objectives
Knowledge needs / science To conduct monitoring and science to
support management of the nature reserve
Water management To effectively engage with water
management system to support functioning ecosystems
Reserve planning and management To effectively plan and manage the reserve network to maximise ecological and social benefits
Ensure data management for evaluation and review is appropriately collected and stored.
Ensure budgets are targeted to key objectives identified in the wetlands adaptive management strategy
Figure 14 Lower-level Enabling Objectives [from (OEH, 2012b)].
Reserve Management Effectively plan for the management of the Nature Reserve
Reserve Management and Planning To effectively plan, manage and develop the Nature Reserve to meet ecological and social objectives
Enabling objectives
Resources, management system and infrastructure
To provide capacity (resources, management system and infrastructure) for effective management of the Nature Reserve To conduct monitoring and science to support management of the nature reserve
Figure 15 Lower-level Enabling Objectives [from (OEH, 2012b)].
Water management
To effectively engage with water management policies, planning and processes to support functioning ecosystems
Ensure that values and objectives of the Adaptive Management Strategy are recognised in the Review of the Water Sharing Plan
Thresholds, restoration targets, and indicators
For each of the key values, appropriate indicator/s should be identified. These should reflect the vital attributes required for long-term viability (Table 7). Indicators should be sensitive to change and could be measured using a range of methods, forming operational goals that articulate the natural spatial and temporal variability. Developing thresholds of potential concern (TPCs) provides a measurable end-point within the strategic adaptive management framework (Kingsford and Biggs, 2012a). TPCs enable setting desirable ecosystems states or conditions against which the success of management actions can be evaluated. As defined by Biggs and Rogers (2003), TPCs are ‘those upper and lower levels, along a continuum of change in selected environmental indicators that provide the basis for decisions on the acceptability of that change’. Importantly, TPC’s should represent points that once crossed, would change management decisions. Thresholds and indicators may involve sophisticated modelling (see sections 3.3.2-4) and/or sensible heuristics (‘rules of thumb’), based on experience or even educated guesses (see section 3.3.1). Uncertainty in thresholds may also be resolved over time. Thresholds are operational goals that define natural spatial and temporal variability, within certain confidence intervals, relative to a potentially natural level.
For some systems, degrading conditions have meant that the thresholds of potential concern have already been crossed. In such cases, TPC’s can be best described as the inverse, namely targets for rehabilitation, and act to inform the objectives by establishing targets for rehabilitation. They then become targets to work ‘back towards’
the desirable condition, as often thresholds may have already been exceeded. In a highly compromised system such as the Macquarie Marshes, TPCs can be usefully restated as targets for rehabilitation within the context of increased flows to the system.
This captures the notion of resilience of ecosystems where indicators and their thresholds identify when a particular ecosystem moves to an undesirable condition (Table 7). For example, restoration of 1756ha of river red gum crown to good condition would immediately return to being a lower bound for a threshold of potential concern.
Each threshold should represent an achievable environmental goal and not designed to be overwhelming or too rigid. They also need to be firm enough to meet essential criteria of transparency should they be exceeded. The threshold themselves are open to ongoing scrutiny, but not when exceedence is reported, given likely contentiousness.
At this time, it is far better to act and learn. Further, allowing sudden recalibration undermines the whole adaptive management system and means the status quo will likely never be found wanting. This underscores the importance of buy-in, or co-creation by researchers, managers, and key stakeholders of the rationale for thresholds and their levels. Identification of indicators and thresholds is an iterative process, it may be necessary to alter or add to the list of indicators, and thresholds after testing the suitability of different management options (see section 3.3).
Table 7: Examples of key values, their selected indicators and the thresholds of potential concern (TPC) and restoration targets as identified by OEH for the Macquarie Marshes (OEH, 2012b)
Key values Indicator TPC
Inundation patterns Inundation frequency and extent 16 events > 350GL, over 20 year cycle Waterbird breeding and habitat Habitat and breeding events Adequate habitat for breeding every 2-3 years
Large breeding event every 10 years
Extent of habitat Extent of breeding habitat maintained or restored
Diversity of habitat Range of wetlands communities to support breeding maintained or restored
River Red Gum Extent and condition To maintain 100% 1427ha of river red gum communities, which is currently in good health, with a healthy understorey in good condition at all times
To restore approx. 3570ha of river red gum community, current in poor condition, to intermediate, or better
To restore approx. 1756 ha of river red gum communities, which is in intermediate condition, so that the crown condition is good and there is a diverse understorey of aquatic plants, grasses and forbs that respond to changes in wetness
Common reeds Extent and condition Maintain 1800 ha of reed bed in the northern section of the Nature Reserve restore a further 600 ha in the southern section of the Nature Reserve
Open water lagoons Frequency of filling and area restored Maintain and restore at least 70 ha of open water lagoons
Coolibah and black box community Extent Coolibah black box That current extent of black box and coolibah within the NR does not decrease
Understorey Coolibah black box That the understorey composition improves as indicated by including semi-permanent wetland communities, grassland and chenopods
Feral pigs Effort per unit culled That control efforts reduce feral pigs populations by >70% per year.
Thresholds of Potential Concern – derivation using data
It is possible, using long-term data, to provide a series of potential thresholds of concern or targets of rehabilitation, built around different confidence intervals for the data. We demonstrate this for colonial waterbirds breeding (see section 3.3.2 for more details) and river red gum health (see section 3.3.4 for more details). For example, the long-term (1986-2011) average abundance of colonial waterbirds across 16 colonies in the Macquarie Marshes is 17,087 with upper 75% confidence intervals of about 15,230 waterbirds (Table 8). A higher bound could be the 90% confidence interval of about 75,230 waterbirds (Table 8). These values can be established as targets of rehabilitation achieved through strategic management of environmental water allocations (see section 3.3.4 for discussion). Clearly, in such a system total abundance is highly variable and can represent species of less concern and so unique species may be more a useful variable (Table 8). This may be further developed by specifying the period between breeding events of certain magnitude. Further, such a threshold may be examined within the context of the likely natural thresholds and frequencies of colonial breeding (Kingsford and Johnson, 1998), tested through assessment of environmental flow scenarios (Kingsford and Auld, 2005a).
Table 8: Potential targets of rehabilitation set by upper (75% and 95%) Confidence Intervals (CI) of mean for colonial waterbird abundances (1986-2011). Frequencies in parentheses refer to the one in ten year frequencies when these levels were exceeded.
Colonial waterbirds Average 0.75% CI 0.90% CI
Total Abundance 17,087 15,230(2.3) 75,230(0.08)
SNI 10,560 9,850(2.3) 53,083.9(0.8)
WHI 926 775(2.3) 3,167.7(0.8)
GLI 381 500(2.7) 1,360(0.8)
IE 3,783 4137(2.3) 197,90(0.8)
GE 99 105(2.3) 230(0.8)
CE 24 14(2.3) 115(0.8)
LE 333 231(2.3) 1,670(0.8)
LBC 97 112(2.3) 417(0.8)
LPC 106 157.5(2.3) 460(0.8)
NH 779 350(2.7) 1278(0.8)
1 Species abbreviations: IE – Intermediate egret, LE – Lesser egret, CE – Cattle egret, GE - Great egret, LBC – Little black cormorant, LPC – Little pied cormorant, NH – Night Heron, SNI – Straw neck ibis, GLI – Glossy ibis, WHI – Australian white ibis. 2 RRG - River red gum woodland.
As well, river red gum health metrics can be used to identify threshold of potential concern relevant to this species, which once crossed would require either alteration of existing management practices or launching new ones (Table 9). The strong spatial component of vegetation to localised conditions means that we can establish more spatially explicit thresholds of potential concern for different locations within the Macquarie Marshes (Figure 16). Using river red gum data (Bacon, 2004, Catelotti, 2012), we estimated confidence intervals both across years (2004-2005, 2011) as well as across individual trees sampled at various locations around the Macquarie Marshes.
Similar thresholds may be easily derived for other response variables providing some quantitative basis for assessment. Actual choice of the threshold of potential concern needs to be a process involving other stakeholders and managers in determining thresholds that relate to values.
Table 9. Potential thresholds of concern provided by lower (19% and 25%) Confidence Intervals (CI) of mean for river red gum health (2003-2005, 2012). Frequencies in parentheses refer to the frequencies individual trees exceeded these limits.
Health metric Average 0.10% CI 0.25% CI Crown position (0-5) 3.44 1.48(0.76) 2.22(0.63) Crown size(0-5) 2.97 1.26(0.08) 2.04(0.22) Crown density (0-9) 4.27 1.43(0.08) 2.35(0.21) Epicormic growth (0-5) 1.89 0.72(0.08) 1.4(0.22) Dead branches (0-3) 2.38 0.82(0.08) 1.6(0.21)
Figure 16: Average frequencies where individual river red gum trees have crossed thresholds of potential concern (25%CI) within the Macquarie Marshes Nature Reserve.
3.2.3. Climate change impacts in the Macquarie Marshes