Maria Rita Pasimeni

Chemical footprints of anthropogenic nitrogen deposition on recent soil C : N ratios in Europe

Long-term human interactions with the natural landscape have produced a plethora of trends and patterns of environmental disturbances across time and space. Nitrogen deposition, closely tracking energy and land use, is known to be among the main drivers of pollution, affecting both freshwater and terrestrial ecosystems. We present a statistical approach for investigating the historical and geographical distribution of nitrogen deposition and the impacts of accumulation on recent soil carbon-to-nitrogen ratios in Europe. After the second Industrial Revolution, large swaths of land emerged characterized by different atmospheric deposition patterns caused by industrial activities or intensive agriculture. Nitrogen deposition affects soil C : N ratios in a still recognizable way despite the abatement of oxidized and reduced nitrogen emissions during the last 2 decades. Given a seemingly disparate land-use history, we focused on ∼ 10 000 unmanaged ecosystems, providing statistical evidence for a rapid response of nature to the chronic nitrogen supply through atmospheric deposition.

Investigating landscape phase transitions in Mediterranean rangelands by recurrence analysis

ContextSocio-ecological landscapes typically characterized by non-linear dynamics in space and time are difficult to be analyzed using standard quantitative methods, due to multiple processes interacting on different spatial and temporal scales. This poses a challenge to the identification of appropriate approaches for analyzing time series that can evaluate system properties of landscape dynamics in the face of disturbances, such as uncontrolled fires.ObjectiveThe purpose is the application of non-linear methods such as recurrence quantification analysis (RQA) to landscape ecology. The examples concern the time series of burnt and unburnt Mediterranean rangelands, to highlight potential and limits of RQA.MethodsWe used RQA together with joint recurrence analysis (JRA) to compare the evolutionary behavior of different land uses.ResultsTime series of forests and grasslands in rangelands present both periodic and chaotic components with a rather similar behavior after the fire and clear transitions from less to more regular/predictable dynamics/succession. Results highlight the impacts of fire, the recovery capacity of land covers to pre-burnt levels, and the decay of synchronization towards the previous regime associated with vegetation secondary succession consistent with early successional species.ConclusionsRQA and JRA with their set of indices (recurrence rate: RR, laminarity: LAM, determinism: DET, and divergence: DIV) can represent new sensitive measures that may monitor the adaptive capacity and the resilience of landscapes. However, future applications are needed to standardize the analysis by strengthening the accuracy of this approach in describing the ongoing transformations of natural and man-managed landscapes.

Emerging Land-Use Cross-Scale Patterns and the Pirsig’s Monkey Trap

We want to draw the attention to some emerging land-use cross-scale patterns resulting from social-economic factors and associated with an historical characteristic sequence of different land-use regimes that could indicate overregulation in social-ecological landscapes (SELs). We postulate that these emerging patterns with clearly defined spatial areas with fixed rules and increasing merging and enlargements of specific functions in some SEL locations are early warning signal of regime shifts and can be typical in many different human-dominated parts of the world. This current overall tendency could make in fact land administration inflexible, and planning may reinforce rigidity, erode resilience, and promote regime shifts and collapse in SELs instead of the adaptability required to counter surprises due, for instance, to climate change. The problem we presently face is how a “static” and “ordered” landscape condition in SELs, provided by the cross-scale intersections of land use, plans, and norms can be made sustainable in face of unpredictable disturbance and change. If we don’t have proper mechanisms to monitor and predict changes and if we are not able to adapt through feedback mechanisms to changes in the environment, we might get stuck in a rigidity trap like the Pirsig’s monkey and we are at high risk for failing. We show that a potential way to address such issues is to look at recent trends of different land-use regimes, along with a simple framework to interpret resulting spatial patterns across scales. We provide examples of this approach and discuss what a cross-scale land-use pattern could mean, what it tells about the condition of SELs, and what the effects could be of changing observed conditions in SELs because of, for instance, climate change. We exercise the approach for the Apulia region in southern Italy taking advantage of recent historical trends observed in main drivers and of the rich information provided by cross-scale pattern analysis in the pattern transition space provided by classic neutral landscape models. We suggest that the degree to which the observed pattern departs from a particular neutral model can indicate whether major constraints or organizing structure has been placed on the landscape and how those landscapes might evolve/react to additional variation due to land use and climate change. The degree of overregulation provided by cross-scale patterns of land use is a warning to planners and managers that the problem is becoming widespread and can no longer be addressed simply with short-term and local-scale solutions. To manage a transition toward more environmentally efficient and, therefore, more sustainable land use, we should design and manage landscape elements and structure to create less contagious and more heterogeneous landscapes. Nevertheless, we have to change societal values at the root of overregulation and rigidity. We have to be aware that we might get stuck in a rigidity trap to appreciate the similarity of our common condition and to start real cooperation.