Linking Terrestrial and Marine Conservation Planning and Threats Analysis

Abstract

The existence of the Gulf of Mexico dead zone makes it clear that marine ecosystems can be damaged by terrestrial inputs. Marine and terrestrial conservation planning need to be aligned in an explicit fashion to fully represent threats to marine systems. To integrate conservation planning for terrestrial and marine systems, we used a novel threats assessment that included 5 cross-system threats in a site-prioritization exercise for the Pacific Northwest coast ecoregion (U.S.A.). Cross-system threats are actions or features in one ecological realm that have effects on species in another realm. We considered bulkheads and other forms of shoreline hardening threats to terrestrial systems and roads, logging, agriculture, and urban areas threats to marine systems. We used 2 proxies of freshwater influence on marine environments, validated against a mechanistic model and field observations, to propagate land-based threats into marine sites. We evaluated the influence of cross-system threats on conservation priorities by comparing MARXAN outputs for 3 scenarios that identified terrestrial and marine priorities simultaneously: (1) no threats, (2) single-system threats, and (3) single- and cross-system threats. Including cross-system threats changed the threat landscape dramatically. As a result the best plan that included only single-system threats identified 323 sites (161,500 ha) at risk from cross-system threats. Including these threats changed the location of best sites. By comparing the best and sum solutions of the single- and cross-system scenarios, we identified areas ideal for preservation or restoration through integrated management. Our findings lend quantitative support to the call for explicitly integrated decision making and management action in terrestrial and marine ecosystems.

Biological Invasions in Conservation Planning: A Global Systematic Review

“…Specifically in the marine environment, the approaches that have been followed so far were to either protect alien biodiversity by setting conservation targets in MARXAN for both native and alien species (Giakoumi et al, 2011), or by estimating cumulative impact indices that included invasive alien species and either incorporate them in the cost function (Tallis et al, 2008), or adequately modify the optimization algorithm of MARXAN (Klein et al, 2013). All the other approaches applied in the freshwater or terrestrial environments can be transferred to the marine environment as well, i.e., exclusion of highly impacted areas Rouget et al, 2003;Pierce et al, 2005;Olson et al, 2010;Reid et al, 2012;Sealey et al, 2014), maximizing contribution to measures of condition and complementarity (Ausseil et al, 2011), or applying a least-cost path analysis including invasive alien species in the cost matrix (Lagabrielle et al, 2009).…”

“…The latter was treated as cost in MARXAN for the prioritization of sites. Tallis et al (2008) estimated cumulative threat indices that included invasive alien species among a number of both terrestrial and marine threats, and incorporated them in the cost function of MARXAN to prioritize terrestrial and marine sites in a cross-environment conservation planning case study. Stewart et al (2017), in addition to prioritizing watersheds based on species presence, developed cost layers representing human threats (land use) and the presence of alien fish.…”

“…To achieve conservation goals, strategies for designing networks of protected areas are needed and should be based on the principles of biodiversity representativeness and persistence, the latter referring to the long-term survival of protected biodiversity by maintaining ecological functions and viable populations and by minimizing threats (Margules and Pressey, 2000). Hence, it is of utmost importance to apply a systematic approach to conservation planning, considering not only the distribution of biodiversity but also of threats (Tallis et al, 2008) and the implementation costs (Naidoo et al, 2006;Carwardine et al, 2008). Such an approach can substantially improve the cost-effectiveness of conservation prioritization for mitigating cumulative threats (Wilson et al, 2006;Auerbach et al, 2014).…”

Using modeling tools for implementing feasible land use and nature conservation governance systems in small islands – The Pico Island (Azores) case-study

“…Tallis et al, 2008;Lagabrielle et al, 2009;Watts et al, 2009;Segan et al, 2011). In this way, it was possible to simultaneously assess both gains and/or losses in comparison to alternative management goals.…”

“…This result constitutes a good way to assess the adequacy of the Marxan framework for targeting areas of interest for conservation in the analyzed context (Tallis et al, 2008;Lagabrielle et al, 2009). Nevertheless, when considering these results from a management perspective, it does not give any indication on the interest of Table 4 Values used to compute nature conservation cost (2nd scenario).…”