Performance of salmon fishery portfolios across western North America

摘要: Summary 1. Quantifying the variability in delivery of ecosystem services across landscape can be used to set appropriate management targets, evaluate resilience and target conservation efforts. Ecosystem functions may exhibit portfolio-type dynamics, whereby diversity within lower levels promotes stability at more aggregated levels. Portfolio theory provides a framework characterize relative performance among ecosystems processes that drive differences performance. 2. We assessed Pacific salmon Oncorhynchus spp. portfolio their native latitudinal range focusing on reliability returns as metric with which assess function humans. 3. Sharpe ratio (e.g. size total return its (risk)) Chinook sockeye portfolios west coast North America. evaluated effects from variance covariance each portfolio, association between watershed attributes. 4. found positive trend risk-adjusted also correlated negatively anthropogenic impact watersheds dams land-use change). High-latitude were average 2� 5 times reliable, risk was mainly due low individual assets. Sockeye reliable higher latitudes, but sources varied highest performing portfolios. 5. Synthesis applications. straightforward method for characterizing services. Natural undeveloped benchmark restoration Locally regionally, assessing guide actions maintain existing (protect habitat disturbance regimes response diversity; employ harvest strategies sensitive different components) or improve activities. Improving our understanding allow natural resources is robust ongoing environmental change.