|Main authors:||Diana Sietz, Luuk Fleskens, Lindsay C. Stringer|
|Source document:||Sietz, D. et al. (2017) Report on integrated modelling strategy. CASCADE Project Deliverable 8.2 33 pp|
Costs and effectiveness are the most important considerations in land management. Their evaluation helps to select the best out of several management options. To assess the socio-ecological effectiveness of land management, we evaluate insights into ecological effects and financial attractiveness. This approach merges major aspects of two economic methods commonly used to inform decision-making on land management: cost-effectiveness and cost-benefit analysis.
In cost-effectiveness analysis, relative costs and outcomes (e.g. ecological effects) of various management strategies are compared. This implies the definition of a specific target, such as a critical threshold in vegetation cover, as a criterion against which each strategy’s performance is evaluated. However, cost-effectiveness analysis is sensitive to subjective decisions in target setting necessitating robust empirically grounded choices that are relevant in a particular management context. For example, 40% vegetation cover was determined a critical threshold to prevent erosion and maintain important ecosystem services in CASCADE study sites (see »Guidelines for natural resource managers).
In contrast, cost-benefit analysis requires all effects to be expressed in monetary values considering the time value of an investment. It compares management options according to cash flows, that is to say time series of monetary costs and benefits, taking into account a discount factor. In CASCADE grazing sites, pasture and livestock productivity are of major interest to land users and can be monetarised in a straightforward way. Yet, cost-benefit analysis has often been criticised regarding the desirability and ways to attribute monetary value to ecosystem services, such as aesthetic, cultural and recreational services and its exclusively forward-looking nature (Anderson et al. 2016).
Despite these concerns, a key question however remains: how can we inform decisions on sustainable land management? Given the complexity of management impacts and potentially long time scales before effects materialise, this question needs to be addressed through scenario studies that establish relevant assumptions and simulate the socio-ecological impacts of various management options. Although land management is a multifaceted process, it can be assumed that land users would consider to adopt only those strategies that yield positive expected returns expressed as costs and benefits and that policy makers’ decisions would depend on cost-effectiveness considerations. A combination of cost-effectiveness and cost-benefit analysis is therefore used in this modelling strategy to evaluate ecological and economic impacts of selected management scenarios (Figure 1).
Ecological impacts are simulated applying an advanced rangeland resilience model that captures the effects of livestock grazing on vegetation dynamics (Kefi et al. 2007, Schneider and Kefi 2016). It allows to assess the impacts of interacting grazing pressure and environmental conditions (e.g. aridity) on ecosystem stability considering time frames that are relevant for land users (e.g. annual time steps over a period of 10-30 years). In particular, this model simulates spatially heterogeneous grazing impacts caused by local facilitation (e.g. shading and water retention when plants grow in patches), associational resistance (i.e. joining physical defences such as spines and thorns) and competition for scarce resources (e.g. water and nutrients). The model development was informed by ecological conditions observed in Randi, Cyprus but can be adjusted to conditions found in other grazing sites. Management strategies such as controlled grazing and supplementary feeding that may imply long-lasting effects and regime shifts receive particular attention. We assume that this type of management directly affects vegetation cover (state of ecosystem) and livestock density captured in the model which in turn influence the chance of restoration in a degraded ecosystem and the risk of degradation in a healthy ecosystem. The ecological assessment is complemented by insights into investment costs (e.g. costs to purchase additional fodder) and income through livestock production (e.g. meat and milk). In contrast, the models investigating fire and drought effects on forests reveal dynamics in the distribution of major functional types including pines and oaks (see »Simulated pressures and ecosystem responses). They demonstrate long-term vegetation dynamics including species succession and recurrence after stress exposure. Due to the specific parameters used, these models do not sufficiently link to the management strategies applied to reduce fire risk and damage in forest stands (e.g. conservational and traditional logging). In addition, the models’ focus on long-term impacts (e.g. >200 years) goes far beyond land users’ planning and decision-making horizons. Therefore, the modelling strategy presented here refers to livestock grazing in the Mediterranean drylands in southern Europe.
Overall, a 5-step modelling approach is presented here to analyse the socio-ecological effectiveness of land management.
- »Step 1: Defining managment scenarios: management scenarios are defined relating to land users’ risk aversion, opportunistic and conservational strategies as well as windows of opportunities and risks arising in particularly dry and wet years
- »Step 2: Assessing ecological impacts of land management: the rangeland resilience model is parametrised in such a way that it represents observed ecological conditions and used to simulate ecological impacts (vegetation cover dynamics) considering the management scenarios and windows of opportunities and risks.
- »Step 3: Estimating economic impacts of land management: economic impacts are investigated based on vegetation cover dynamics, investment costs and livestock income yielding cash flow series.
- »Step 4: Uncertainty analysis: sensitivity analysis is performed to test the robustness of results.
- »Step 5: Evaluating socio-ecological effectiveness: socio-ecological effectiveness of management scenarios is evaluated and discussed with stakeholders to validate the findings. This approach is outlined in more detail in the following sections.
Note: For full references to papers quoted in this article see