Date Published: April 23, 2019
Publisher: Public Library of Science
Author(s): Lorenzo Menichetti, Laura Touzot, Katarina Elofsson, Riitta Hyvönen, Thomas Kätterer, Petter Kjellander, Pedro G. Blendinger.
Landscapes composed of agricultural land mixed with forest are desirable since they provide a wide range of diversified ecosystem services, unlike specialized agricultural landscapes, but that creates a trade-off between these land uses since wildlife usually feed on crops and reduce yields. In Nordic countries, where human population density is low and game hunting can be a viable economic alternative, mixed landscape systems are particularly interesting. To evaluate the economic sustainability of such systems we need to quantify wildlife damage to crops. One important species, being popular among Swedish hunters and therefore economically valuable, is fallow deer (Dama dama). Our objective was to evaluate the economic sustainability of mixed landscape systems including cultivated fields and commercial hunting of fallow deer. We studied the effects of excluding fallow deer by using 86 exclosures and adjacent plots in winter wheat and oat fields in south-west Sweden. We analyzed yield losses and interactions between spatial and temporal grazing patterns, anthropogenic landscape features, and topological characteristics of the landscape. We found that animals avoided exposed spots, irrespective of distance from human activity. We also found a seasonal grazing pattern related to the different growing periods of winter wheat (more grazed, emerging in autumn) and spring oat (less grazed, emerging in spring). We then compared the costs of crop damage against the commercial value of fallow deer hunting. The damage amounted to 375 ±196 € ha-1 for wheat and 152 ±138 € ha-1 for oat, corresponding to a total cost per animal of 82.7 ±81.0 €, while each animal had an estimated market value of approximately 100 €. Therefore the value of fallow deer presence compensated for the associated cost of crop damage. Profit could be further improved in this case by adopting additional management strategies. In general our study confirmed the economic feasibility of this particular mixed land management.
Global demand for food is expected to increase substantially in the future. However, food production is often in conflict with other land-based ecosystem services relating to wildlife, since the objective of food production implies the minimization of ungulate density in order to avoid damage to crop. But wildlife can provide many other ecosystem services such as higher spatial and species diversity, carbon sequestration potential [1–3], erosion control  and recreational and cultural services [5,6] which make a high wildlife density desirable. The population density of wild ungulates has been increasing in Europe in recent decades . Many wild ungulates have opportunistic feeding behaviors and feed on crops [8,9], so their impact on economic profit is generally considered negative . Compensation for wildlife damage to crops is the second largest class of agricultural compensation of any kind world-wide, after livestock damage caused by carnivores. It represents 35% of the total global amount of compensation to agriculture (which has been on average approximately 8 million € per year over the past five decades), even though its effectiveness in mitigating human-wildlife conflicts is still not well proven . Moreover, the reduction in landscape complexity caused by agricultural intensification could threaten the resilience of agricultural environments , since landscape heterogeneity has been positively related to ecological processes such as pollination . Landscape heterogeneity is also correlated directly with perceived landscape recreational value  and with recreational  and cultural  ecosystem services. In temperate environments, increasing landscape heterogeneity means finding a practical solution to manage landscapes incorporating forests and cropland, which can be achieved through increasing the economic sustainability of such systems.
We found that animals avoided exposed spots, irrespective of distance from human activity (aim 1). We also found a seasonal grazing pattern related to the different growing periods of winter wheat (more grazed) and spring oat (less grazed). In monetary terms, the value of fallow deer presence compensated for the associated cost of crop damage (aim 2). Below we will discuss these results and its implications in more detail.