Winter condition variability decreases the economic sustainability of reindeer husbandry

Abstract

Wild and semidomesticated reindeer are one of the key species in Arctic and subarctic areas, and their population dynamics are closely tied to winter conditions. Difficult snow conditions have been found to decrease the calving success and survivability of reindeer, but the economic effects of variation in winter conditions on reindeer husbandry have not been studied. In this study, we combine state-of-the-art economic-ecological modeling with the analysis of annual reindeer management reports from Finland. These contain local knowledge of herding communities. We quantify the occurrence probabilities of different types of winters from annual management reports and analyze the effects of this variation in winter conditions on reindeer husbandry using an age- and sex-structured bioeconomic reindeer-lichen model. Our results show that difficult winters decrease the net revenues of reindeer husbandry. However, they also protect lichen pastures from grazing, thereby increasing future net revenues. Nonetheless, our solutions show that the variability of winter conditions overall decrease the net income of herders compared to constant winter conditions. Low lichen biomass appears to make reindeer management more sensitive to the effects of difficult winter conditions. We also found that it is economically sensible to use supplementary feeding during difficult winters, but the net revenues still decrease compared to average winters because of the high feeding costs. Overall, our analysis suggests that the increasing variability of winter conditions due to climate change will decrease net revenues in reindeer husbandry. This decrease will still occur even if the most extreme effects of climate change do not occur. This study shows that combining a state-of-the-art bioeconomic model and practitioner knowledge can bring compatible insights, ideas, results, and a bottom-up perspective to the discussion.

Keywords: adaptation to climate change; bioeconomic modeling; economic sustainability; practitioner knowledge; reindeer (Rangifer tarandus tarandus); reindeer husbandry; snow conditions; supplementary feeding; winter weather.

FIGURE 1

Model solutions compared with data from 20 northernmost reindeer herding districts in Finland. Figures are originally presented in Pekkarinen et al. (2017) and redrawn using the original data sets. (a, b) Measured data points compared with model predictions. (c) Comparison of observed reindeer numbers with economically optimal model solutions.

FIGURE 2

Mean temperature and precipitation in January at Inari weather station in northernmost Finnish Lapland. Panels present annual deviation from long‐term (1981–2010) average mean temperature (−12.7°C) and average precipitation (25 mm) in January.

FIGURE 3

Examples of dynamic economically optimal solutions with 0%, 3%, and 5% interest rates. The black line represents a solution with constant winter conditions (average winters); the red dashed line indicates a solution with stochastic winter conditions (easy, average, and difficult winters vary according to the estimated probabilities [10%, 80%, 10%]).

FIGURE 4

Optimal slaughtering strategy predicted by the model compared with data from the northernmost reindeer herding districts in Finland over three decades during the latest climatological standard period. Black symbols denote model solutions, white symbols represent data. The sum of the shares (live calves + slaughtered calves + live adults + slaughtered adults) represents the total population size just before autumn slaughtering. The comparison shows that the slaughtering strategies in the districts have evolved toward the model solution.

FIGURE 5

Economically optimal adaptation to a single difficult winter. Optimal solutions computed with 0%, 1%, and 3% interest rates.

FIGURE 6

Effect of a single easy winter for annual net revenues from reindeer husbandry in an optimal steady state. Optimal solutions computed with 0%, 1%, and 3% interest rates.

FIGURE 7

Effects of stochastic winter conditions for reindeer herding economy. Optimal solutions presented for 0%, 1%, 3%, and 5% interest rates. Black lines represent deterministic solutions with constant winter conditions. Red lines show optimal feedback solutions with stochastic winters. Upper panels show example of a single deterministic and single stochastic solution. Lower panels show example of 20 different stochastic solutions with single deterministic solutions.

FIGURE 8

Effects of stochastic winter conditions for reindeer herding economy. Optimal solutions presented for different frequencies of easy and difficult winters. The probabilities of difficult and easy winters are 10%, 20%, and 40% for panels (a), (b), and (c), respectively.

FIGURE 9

Example of economically optimal solutions with stochastic winter conditions and 3% interest rate. Black lines represent solutions with possibility of supplementary feeding, with feeding costs of €0.5/kg. Red dashed lines represent solutions where providing supplementary food is not possible. The lower lines represent the feeding costs and the upper lines total net revenues.