Julia Touza

Spatial distribution of human-caused forest fires in Galicia (NW Spain).

It is crucial for fire prevention policies to assess the spatial patterns of human-started fires and their relationship with geographical and socioeconomic aspects. This study uses fire reports for the period 1988-2006 in Galicia, Spain, to analyze the spatial distribution of human-induced fire risk attending to causes and underlying motivations associated with fire ignitions. Our results show that there are four distinctive types of municipalities in this region according to the incidence of intentional agricultural-livestock fires, pyromaniacal behavior, negligence, and unknown causes. They highlight that study of the spatial properties of the human causes and motivations of forest fire activity can provide valuable information for detecting the presence of non-random clusters of fires of various causes in particular locations, where fire management planning should be evaluated more in depth.

Forecasting intentional wildfires using temporal and spatiotemporal autocorrelations

We report daily time series models containing both temporal and spatiotemporal lags, which are applied to forecasting intentional wildfires in Galicia, Spain. Models are estimated independently for each of the 19 forest districts in Galicia using a 1999-2003 training dataset and evaluated out-of-sample with a 2004-06 dataset. Poisson autoregressive models of order P - PAR(P) models - significantly out-perform competing alternative models over both in-sample and out-of-sample datasets, reducing out-of-sample root-mean-squared errors by an average of 15%. PAR(P) and static Poisson models included covariates deriving from crime theory, including the temporal and spatiotemporal autoregressive time series components. Estimates indicate highly significant autoregressive components, lasting up to 3 days, and spatiotemporal autoregression, lasting up to 2 days. Models also applied to predict the effect of increased arrest rates for illegal intentional firesetting indicate that the direct long-run effect of an additional firesetting arrest, summed across forest districts in Galicia, is -139.6 intentional wildfires, equivalent to a long-run elasticity of -0.94. Language: en

Documenting Social Simulation Models: The ODD Protocol as a Standard

The clear documentation of simulations is important for their communication, replication, and comprehension. It is thus helpful for such documentation to follow minimum standards. The ‘overview, design concepts, and details’ document protocol (ODD) is specifically designed to guide the description of individual- and agent-based simulation models (ABMs) in journal articles. Popular among ecologists, it is also increasingly used in the social simulation community. Here, we describe the protocol and give an annotated example of its use, with a view in facilitating its wider adoption and encouraging higher standards in simulation description.

Integrating invasive species policies across ornamental horticulture supply chains to prevent plant invasions

Research was supported by COST Action TD1209 “Alien Challenge”. The authors are grateful to John David and Franziska Humair for valuable discussions on this topic. PP and JP were supported by project no. 14-36079G Centre of Excellence PLADIAS (Czech Science Foundation) and RVO 67985939 (The Czech Academy of Sciences). FE, SD, MC and MvK were supported by the ERA-Net BiodivERsA through the Austrian Science Fund, German Research Foundation and French National Research Agency. AN was supported by the Working for Water (WfW) Programme and the DST-NRF Centre of Excellence for Invasion Biology. HS acknowledges support by the DFG (grant SE 1891/2-1).

To shape or to be shaped: engaging stakeholders in fishery management advice

The purpose of this paper is to assess the effectiveness of the collaboration between stakeholders and scientists in the construction of a bio-economic model to simulate management strategies for the fisheries in Iberian Atlantic waters. For three years, different stakeholders were involved in a model development study, participating in meetings, surveys and workshops. Participatory modelling involved the definition of objectives and priorities of stakeholders, a qualitative evaluation and validation of the model for use by decision-makers, and an iterative process with the fishing sector to interpret results and introduce new scenarios for numerical simulation. The results showed that the objectives of the participating stakeholders differed. Incorporating objectives into the design of the model and prioritising them was a challenging task. We showed that the parameterization of the model and the analysis of the scenarios results could be improved by the fishers’ input: e.g. ray and skate stocks were explicitly included in the model; and the behaviour of fleet dynamics proved much more complex than assumed in any traditional modelling approach. Overall, this study demonstrated that stakeholder engagement through dialogue and many interactions was beneficial for both, scientists and the fishing industry. The researchers obtained a final refined model and the fishing industry benefited for participating in a process, which enables them to influence decisions that may affect them directly (to shape) whereas non-participatory processes lead to management strategies being imposed on stakeholders (to be shaped).

The changing role of ornamental horticulture in alien plant invasions

The number of alien plants escaping from cultivation into native ecosystems is increasing steadily. We provide an overview of the historical, contemporary and potential future roles of ornamental horticulture in plant invasions. We show that currently at least 75% and 93% of the global naturalised alien flora is grown in domestic and botanical gardens, respectively. Species grown in gardens also have a larger naturalised range than those that are not. After the Middle Ages, particularly in the 18th and 19th centuries, a global trade network in plants emerged. Since then, cultivated alien species also started to appear in the wild more frequently than non‐cultivated aliens globally, particularly during the 19th century. Horticulture still plays a prominent role in current plant introduction, and the monetary value of live‐plant imports in different parts of the world is steadily increasing. Historically, botanical gardens – an important component of horticulture – played a major role in displaying, cultivating and distributing new plant discoveries. While the role of botanical gardens in the horticultural supply chain has declined, they are still a significant link, with one‐third of institutions involved in retail‐plant sales and horticultural research. However, botanical gardens have also become more dependent on commercial nurseries as plant sources, particularly in North America. Plants selected for ornamental purposes are not a random selection of the global flora, and some of the plant characteristics promoted through horticulture, such as fast growth, also promote invasion. Efforts to breed non‐invasive plant cultivars are still rare. Socio‐economical, technological, and environmental changes will lead to novel patterns of plant introductions and invasion opportunities for the species that are already cultivated. We describe the role that horticulture could play in mediating these changes. We identify current research challenges, and call for more research efforts on the past and current role of horticulture in plant invasions. This is required to develop science‐based regulatory frameworks to prevent further plant invasions.

Agricultural landscape structure and invasive species: the cost-effective level of crop field clustering

Invasive pests in agricultural settings may have severe consequences for agricultural production, reducing yields and the value of crops. Once an invader population has established, controlling it tends to be very expensive. Therefore, when the potential impacts on production may be great, protection against initial establishment is often perceived to be the most cost-effective measure. Increasing attention in the ecological literature is being given to the possibility of curbing invasion processes by manipulating the field and cropping patterns in agricultural landscapes, so that they are less conducive to the spread of pests. However, the economic implications of such interventions have received far less attention. This paper uses a stochastic spatial model to identify the key processes that influence the vulnerability of a fragmented agricultural landscape to pests. We explore the interaction between the divergent forces of ecological invasion pressure and economic returns to scale, in relation to the level of clustering of crop fields. Results show that the most cost-effective distances between crop fields in terms of reducing food production impacts from an invasive pest are determined by a delicate balance of these two forces and depend on the values of the ecological and economic parameters involved. If agricultural productivity declines slowly with increasing distance between fields and the dispersal range of the potential invader is high, manipulation of cropping structure has the potential to protect against invasion outbreaks and the farmer can gain benefit overall from maintaining greater distances between fields of similar crops.

Livestock Disease Management for Trading Across Different Regulatory Regimes

The maintenance of livestock health depends on the combined actions of many different actors, both within and across different regulatory frameworks. Prior work recognised that private risk management choices have the ability to reduce the spread of infection to trading partners. We evaluate the efficiency of farmers’ alternative biosecurity choices in terms of their own-benefits from unilateral strategies and quantify the impact they may have in filtering the disease externality of trade. We use bovine viral diarrhoea (BVD) in England and Scotland as a case study, since this provides an example of a situation where contrasting strategies for BVD management occur between selling and purchasing farms. We use an agent-based bioeconomic model to assess the payoff dependence of farmers connected by trade but using different BVD management strategies. We compare three disease management actions: test-cull, test-cull with vaccination and vaccination alone. For a two-farm trading situation, all actions carried out by the selling farm provide substantial benefits to the purchasing farm in terms of disease avoided, with the greatest benefit resulting from test-culling with vaccination on the selling farm. Likewise, unilateral disease strategies by purchasers can be effective in reducing disease risks created through trade. We conclude that regulation needs to balance the trade-off between private gains from those bearing the disease management costs and the positive spillover effects on others.

Fire Risk At The Wildland-urban Interface:A Case Study Of A Galician County

In Galicia (Spain), wildfires are one of the main environmental problems, with an annual average of close to 8,600 forest fires between 1999 and 2008. Most of these fires are intentionally ignited. It is therefore crucial for fire prevention policies to assess human-started fires and their relationship with socioeconomic aspects. In this paper we focus on the spatial pattern of human presence in the territory as an important determinant on forest fires ignitions. We identify, classified and map wildland-urban interface (WUI) and assess fire risk by types of WUI in a Galician county with one of the highest incidence of forest fires during the studied period (1999-2008). Following Lampin-Maillet et al. (Mapping wildland-urban interfaces at large scales integrating housing density and vegetation aggregation for fire prevention in the South of France. Journal of Environmental Management 2010) approach, and based on a combination of a map of buildings, obtained from the National Topographic Base, and the SIOSE land-cover map (Information system of land use cover in Spain) we distinguished among 12 types of interfaces. Our results show a significant relationship between the different types of WUI and the spatial patterns of wildfire ignition points. The highest density of fire ignition points was found in non-forest WUI with either dispersed or very dense clustered buildings.