Stochastic Flow Connectivity

Connectivity analysis is an important geomorphological and hydrologic tool that can be used to identify spaces that are prone to removal of primary sediments which are eventually assimilated into granular flows and related epiclastic processes. Studies of connectivity have been made in various areas, but to date, not in active volcanic areas, where such studies can be very useful due to the constant presence of loose volcanic material easily removed by epiclastic processes. Mobilization of loose pyroclastic sediments can trigger phenomena such as lahars, which are among the most dangerous in nature. In this study, the index of connectivity (IC) (Borselli et al. 2008) was calculated by obtaining a weight coefficient (W) combining two elements: the coefficient C related to the universal soil loss equation and the revised universal soil loss equation (USLE-RUSLE) proposed by Borselli et al. (2008) for areas with vegetation cover or crops, and the roughness index (RI) developed by Cavalli et al. (2013), which characterizes bare soil areas. Combining both methods, we propose a new joint index of connectivity (IC J) that does not overestimate the degree of connectivity in bare areas, while areas with vegetation cover are characterized based on their wellrecognized hydrologic impedance properties. This methodology may enable better characterization in highly dynamic environments such as active volcanic areas. We also propose a new lateral hydrological efficiency index (LHEI) that increases the ability to identify watersheds that supply major amounts of sediment to main streams in ravines. The application of this methodology in the active volcanic area of Volcán de Colima, the most active volcano in Mexico, is of great importance, because of the constant supply of new pyroclastic material from the top of the edifice, the high dynamicity of geomorphological processes, and the widespread presence of bare soil areas consisting of loose materials easily sourced, or assimilated, into epiclastic processes.

Connectivity analysis is an important geomorphological and hydrologic tool that can be used to identify spaces that are prone to removal of primary sediments which are eventually assimilated into granular flows and related epiclastic processes. Studies of connectivity have been made in various areas, but to date, not in active volcanic areas, where such studies can be very useful due to the constant presence of loose volcanic material easily removed by epiclastic processes. Mobilization of loose pyroclastic sediments can trigger phenomena such as lahars, which are among the most dangerous in nature. In this study, the index of connectivity (IC) (Borselli et al. 2008) was calculated by obtaining a weight coefficient (W) combining two elements: the coefficient C related to the universal soil loss equation and the revised universal soil loss equation (USLE-RUSLE) proposed by Borselli et al. (2008) for areas with vegetation cover or crops, and the roughness index (RI) developed by Cavalli et al. (2013), which characterizes bare soil areas. Combining both methods, we propose a new joint index of connectivity (IC J) that does not overestimate the degree of connectivity in bare areas, while areas with vegetation cover are characterized based on their wellrecognized hydrologic impedance properties. This methodology may enable better characterization in highly dynamic environments such as active volcanic areas. We also propose a new lateral hydrological efficiency index (LHEI) that increases the ability to identify watersheds that supply major amounts of sediment to main streams in ravines. The application of this methodology in the active volcanic area of Volcán de Colima, the most active volcano in Mexico, is of great importance, because of the constant supply of new pyroclastic material from the top of the edifice, the high dynamicity of geomorphological processes, and the widespread presence of bare soil areas consisting of loose materials easily sourced, or assimilated, into epiclastic processes.

Connectivity analysis is an important geomorphological and hydrologic tool that can be used to identify spaces that are prone to removal of primary sediments which are eventually assimilated into granular flows and related epiclastic processes. Studies of connectivity have been made in various areas, but to date, not in active volcanic areas, where such studies can be very useful due to the constant presence of loose volcanic material easily removed by epiclastic processes. Mobilization of loose pyroclastic sediments can trigger phenomena such as lahars, which are among the most dangerous in nature. In this study, the index of connectivity (IC) (Borselli et al. 2008) was calculated by obtaining a weight coefficient (W) combining two elements: the coefficient C related to the universal soil loss equation and the revised universal soil loss equation (USLE-RUSLE) proposed by Borselli et al. (2008) for areas with vegetation cover or crops, and the roughness index (RI) developed by Cavalli et al. (2013), which characterizes bare soil areas. Combining both methods, we propose a new joint index of connectivity (IC J) that does not overestimate the degree of connectivity in bare areas, while areas with vegetation cover are characterized based on their wellrecognized hydrologic impedance properties. This methodology may enable better characterization in highly dynamic environments such as active volcanic areas. We also propose a new lateral hydrological efficiency index (LHEI) that increases the ability to identify watersheds that supply major amounts of sediment to main streams in ravines. The application of this methodology in the active volcanic area of Volcán de Colima, the most active volcano in Mexico, is of great importance, because of the constant supply of new pyroclastic material from the top of the edifice, the high dynamicity of geomorphological processes, and the widespread presence of bare soil areas consisting of loose materials easily sourced, or assimilated, into epiclastic processes.

Connectivity analysis is an important geomorphological and hydrologic tool that can be used to identify spaces that are prone to removal of primary sediments which are eventually assimilated into granular flows and related epiclastic processes. Studies of connectivity have been made in various areas, but to date, not in active volcanic areas, where such studies can be very useful due to the constant presence of loose volcanic material easily removed by epiclastic processes. Mobilization of loose pyroclastic sediments can trigger phenomena such as lahars, which are among the most dangerous in nature. In this study, the index of connectivity (IC) (Borselli et al. 2008) was calculated by obtaining a weight coefficient (W) combining two elements: the coefficient C related to the universal soil loss equation and the revised universal soil loss equation (USLE-RUSLE) proposed by Borselli et al. (2008) for areas with vegetation cover or crops, and the roughness index (RI) developed by Cavalli et al. (2013), which characterizes bare soil areas. Combining both methods, we propose a new joint index of connectivity (IC J) that does not overestimate the degree of connectivity in bare areas, while areas with vegetation cover are characterized based on their wellrecognized hydrologic impedance properties. This methodology may enable better characterization in highly dynamic environments such as active volcanic areas. We also propose a new lateral hydrological efficiency index (LHEI) that increases the ability to identify watersheds that supply major amounts of sediment to main streams in ravines. The application of this methodology in the active volcanic area of Volcán de Colima, the most active volcano in Mexico, is of great importance, because of the constant supply of new pyroclastic material from the top of the edifice, the high dynamicity of geomorphological processes, and the widespread presence of bare soil areas consisting of loose materials easily sourced, or assimilated, into epiclastic processes.

Connectivity analysis is an important geomorphological and hydrologic tool that can be used to identify spaces that are prone to removal of primary sediments which are eventually assimilated into granular flows and related epiclastic processes. Studies of connectivity have been made in various areas, but to date, not in active volcanic areas, where such studies can be very useful due to the constant presence of loose volcanic material easily removed by epiclastic processes. Mobilization of loose pyroclastic sediments can trigger phenomena such as lahars, which are among the most dangerous in nature. In this study, the index of connectivity (IC) (Borselli et al. 2008) was calculated by obtaining a weight coefficient (W) combining two elements: the coefficient C related to the universal soil loss equation and the revised universal soil loss equation (USLE-RUSLE) proposed by Borselli et al. (2008) for areas with vegetation cover or crops, and the roughness index (RI) developed by Cavalli et al. (2013), which characterizes bare soil areas. Combining both methods, we propose a new joint index of connectivity (IC J) that does not overestimate the degree of connectivity in bare areas, while areas with vegetation cover are characterized based on their well-recognized hydrologic impedance properties. This methodology may enable better characterization in highly dynamic environments such as active volcanic areas. We also propose a new lateral hydrological efficiency index (LHEI) that increases the ability to identify watersheds that supply major amounts of sediment to main streams in ravines. The application of this methodology in the active volcanic area of Volcán de Colima, the most active volcano in Mexico, is of great importance, because of the constant supply of new pyroclastic material from the top of the edifice, the high dynamicity of geomorphological processes, and the widespread presence of bare soil areas consisting of loose materials easily sourced, or assimilated, into epiclastic processes.

To date, corridors for species dispersals have been thought as deterministic outputs emerging from some kind of model. Uncertainty about the individuation of biotic corridors has never been considered. Flow connectivity (FC) is a methodology first introduced in 2013 to forecast biotic flows over real landscapes, alternative to both circuit theory and least-cost modelling. Its name is due to the fact that it resembles in some way the motion characteristic of fluids over a surface. FC predicts species dispersal by minimizing at each time step the potential energy due to fictional gravity force over a frictional 3D landscape built upon the real landscape. In this work, FC is further developed to find a solution to the problem of calculating the uncertainty associated to the forecast of species dispersals. The output of this method is an " uncertainty polygon " (e.g., 5% or 10% uncertainty) around the predicted biotic flow. The importance of this new variant of FC is clear: when planning greenways for biodiversity, uncertainty about biotic flows prediction must be taken into account and the planned corridors must encompass the " uncertainty polygon " as well, otherwise they are at serious risk to underestimate the necessary space required by animal species to flow over landscape.

Connectivity in ecology deals with the problem of how biotic dispersals can happen, given actual landscape properties and species presence/absence over such landscape. Recently I have introduced a modelling approach (flow connectivity) to ecological connectivity that is alternative to circuit theory, and is able to fix the weak point of the "from-to" connectivity approach. In addition, I've introduced "reverse flow connectivity" that couples evolutionary algorithms to partial differential equations in order to fix the problem of subjectivity in the attribution of friction values to landscape categories. I've also showed that flow connectivity can be used to predict biotic movements happened in the past (backward flow connectivity). To date, there has been little effort by conservation scientists towards detecting restoration opportunities by mapping barriers that strongly reduce movement potential. In this paper, I introduce a new kind of theoretical and modelling approach called "sloping flow connectivity". The goal of such proposal is to individuate and map barriers and facilities to species dispersals over the landscape. I define here a barrier as a landscape feature that impedes biotic movements, the removal of which would increase the potential for biotic shifts. Using sloping flow connectivity, it's possible to plan greenways and ecological networks in an effective manner, since it is able to enhance the real potential of each landscape elements to facilitate or obstruct both directional and overall species movements.

Connectivity in ecology deals with the problem of how species dispersal will happen given actual landscape and species presence/absence over such landscape. Hence it can be considered a forward (ahead in time) scientific problem. I observe here that a backward theory of connectivity could be of deep interest as well: given the actual species presence/absence on the landscape, where with the highest probability such species is coming from? In other words, can we trace biotic dispersals back in time? Recently I have introduced a modelling and theoretical approach to ecological connectivity that is alternative to circuit theory and is able to fix the weak point of the "from-to" connectivity approach. The proposed approach holds also for mountain and hilly landscapes. In addition, it doesn't assume any intention for a species to go from source points to sink ones, because the expected path for the species is determined locally (pixel by pixel) by landscape features. In this paper, I introduce a new theoretical and modelling approach called "backward flow connectivity". While flow connectivity predicts future species dispersal by minimizing at each step the potential energy due to fictional gravity over a frictional landscape, backward flow connectivity does exactly the opposite, i.e. maximizes potential energy at each step sending back the species to higher levels of potential energy due to fictional gravity on the frictional landscape. Using backward flow connectivity, one has at hand a new tool to revert timeline of species dispersal, hence being able to trace backward biotic dispersals. With few modifications, the applications of backward flow connectivity can be countless, for instance tracing back-in-time not only plants and animals but also ancient human migrations and viral paths.

Recently, I showed that ecological and biological networks can be controlled by coupling their dynamics to evolutionary modelling. This provides numerous solutions to the goal of guiding a system's behaviour towards the desired result. In this paper, I face another important question: how reliable is the achieved solution? In other words, which is the degree of uncertainty about getting the desired result if values of edges and nodes were a bit different from optimized ones? This is a pivotal question, because it's not assured that while managing a certain system we are able to impose to nodes and edges exactly the optimized values we would need in order to achieve the desired results. In order to face this topic, I have formulated here a 3-parts framework (network dynamics -genetic optimization -stochastic simulations) and, using an illustrative example, I have been able to detect the most reliable solution to the goal of network control. The proposed framework could be used to: a) counteract damages to ecological and biological networks, b) safeguard rare and endangered species, c) manage systems at the least possible cost, and d) plan optimized bio-manipulations.

We present here the first description of recorded sexual differences in flight behaviour and space use of lesser kestrel Falco naumanni. Lesser kestrel is a migratory, colonial, small falcon breeding mainly in holes and crevices in large historic buildings within towns and villages, or in abandoned farm houses across the countryside. Using accurate GPS data-loggers, we gathered data on the activities of lesser kestrels in the two of main colonies of lesser kestrels in Italy, i.e. Gravina in Puglia and Altamura (Apulia, Southern Italy) and the surrounding rural areas in a 20-days monitoring during the reproductive period. We tested for sex differences in space use (home range's circularity ratio) and flight attributes (5-minute flight length, instantaneous speed, distance from nest, flight altitude above ground level) of 9 monitored individuals (4 males and 5 females). We found significant sexual differences for all the observed traits. Our results demonstrate that female lesser kestrels during the monitoring period employed a lower amount of energy in local movements as measured by four flight attributes that resulted significantly different (and lower) than for males. Compact home ranges for females could represent a maximization of the benefit-cost ratio between prospected surface and distance from nest, i.e. the optimal trade-off between foraging requirements (explored surface) and costs in terms of time and energy (distance from nest). On the contrary, males showed a significantly different space use with very elongated home ranges and mean distance from nest almost three times as elevated as females' one. We argue that the detected sexual divergence was the product of their respective ways to optimize the relationship between resource acquisition and reproductive activity.