One Ecosystem :
Ecosystem Service Mapping
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Corresponding author: Floriane Jacquemin (floriane_jacquemin@hotmail.com)
Academic editor: Bilyana Borisova
Received: 17 May 2017 | Accepted: 12 Jul 2017 | Published: 26 Jul 2017
© 2017 Floriane Jacquemin, Cyrille Violle, Pierre Rasmont, Marc Dufrêne
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Jacquemin F, Violle C, Rasmont P, Dufrêne M (2017) Mapping the dependency of crops on pollinators in Belgium. One Ecosystem 2: e13738. https://doi.org/10.3897/oneeco.2.e13738
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Because of their pollinating activity, insect pollinators provide an ecosystem service that is essential to ecosystems and our economy. A large majority of the flowering plants we consume depends on it. In turn, the decline in pollinators observed for the last decades in Belgium as in many other European countries threatens agriculture and human well-being.
Here we evaluate the pollination service at a country-wide scale through the estimated value of the contribution of insect pollination to the production used for human consumption in Belgium using crop dependency ratios. We then mapped the vulnerability of crops in the face of pollinator decline at the provincial level.
We show that the part of plant production for human food that we can attribute to the action of insect pollinators represents a value of about 251.6 million euros in 2010 in Belgium. As a result, 11.1 % of total value of Belgian plant production (in terms of fruit quantity and quality) depend on pollinators.
Although the applied method to assess the pollination service estimates only a minimum value of a single aspect of the pollination service, it allows to target the areas of the country where this service is particularly at risk and where it is necessary to define pollinator conservation measures to maintain, and possibly restore current yields.
Crop, biodiversity, pollination service, dependency ratio, vulnerability index.
More than 80% of flowering plant species in the world depend on pollinators, especially insects (mainly from Lepidoptera, Coleoptera, Diptera and Hymenoptera genera) to ensure their reproduction (
By pollinating wild and cultivated plant species (
Many countries worldwide have encountered an overall loss of their wild pollinators for the last decades (
As a result, the decline in pollinators threatens the pollination service they offer (
The objective of this study is to evaluate the contribution of pollinators to Belgian crop production for human consumption so as to figure out how threatened it is depending on the area. This also makes it possible to discuss the relevance of certain agri-environmental measures taking into account these dependency relationships between crops and pollinators.
Our evaluation of the pollination service is based on a methodology established on a global scale by
Based on this method, the economic value of the pollination service is estimated by the contribution of pollinators to the market value of Belgian crop production intended for human consumption (
\(PEV = \sum_{i=1}^{I}\sum_{j=1}^{J} P_{ij} \times Q_{ij} \)
Function 1. Total production economic value (€).
\(IPEV = \sum_{i=1}^{I} \sum_{j=1}^{J} P_{ij} \times Q_{ij} \times D_{i}\)
Function 2. Insect pollination economic value (€).
\(RV = {IPEV \over PEV}\)
Function 3. Rate of vulnerability of crops (%) to pollinator insect disappearance.
The results obtained by crop category at the national scale for the reference year 2010 are listed in Table
Total value of crop production (PEV, €), pollination service (IPEV, €) and vulnerability (RV, %) of crop categories used as human food in Belgium in 2010.
Crop category |
Total value of crop production (PEV, million €) |
Total value of pollination service (IPEV, million €) |
Vulnerability index (RV, %) |
Cereals |
476.88 |
0.00 |
0.00 |
Fruits |
320.41 |
205.27 |
64.06 |
Oilcrops |
6.06 |
1.82 |
30.00 |
Pulse |
1.57 |
0.17 |
10.97 |
Roots and Tubers |
409.12 |
0.00 |
0.00 |
Stimulant crops |
0.26 |
0.00 |
0.00 |
Sugar crops |
119.21 |
0.00 |
0.00 |
Vegetables |
992.50 |
44.37 |
4.47 |
Total |
2264.70 |
251.62 |
11.11 |
The rate of vulnerability of crops used for human food is about 11.1% at the national scale and ranges from 0.0% (Brussels Capital) to 41.1% (Limburg) at the provincial one. Even if these values of the pollination service depends heavily on our knowledge of pollination requirements which may vary between varieties and area (
It should be noted that products of some large Belgian crops (e.g., cereals, sugar beets) are not entirely used for human consumption (
Estimates of potential production loss would also be more realistic if taking into account the rate of decline of pollinators and their substitutability, but also changes in other factors than only pollinator decline. Currently this caveat cannot be taken into account in the production function proposed by
The hypothesis of total disappearance of the pollinators which is behind these calculations is binding or even unrealistic. Although local extinction is feasible, it is unlikely to occur on a larger scale. Nevertheless, the mapping of these indices highlights the geographical distribution of the preservation issues of pollinators and show the importance of preserving pollinating activity to ensure the sustainability of Belgian agricultural production. In this sense, it could constitute a tool to aid decision to prioritize conservation measures of pollinators on Belgian territory, including the implementation of agri-environmental schemes (e.g., sown wildflower strips, high biological value meadows). They generally enhance species richness and abundance of major pollinator groups but not rare and/or declining species. Thus, they preserve the crop pollination service but their role in the conservation of threatened pollinator species is limited (
Although many of the largest production areas are independent on pollinators (cereals) and are wind-pollinated, a large portion of fruit crops (e.g., apple, pears, cherries) are potentially vulnerable to pollinator decline. Because insect pollination is the most effective natural pollination method, if it becomes insufficient, it can be replaced only by an action of man to maintain yields (
To better assess pollination service, more information is needed to understand how the dependency of crop production on pollinators varies, including in relation to crop variety, production area, and pollinator diversity and abundance (
Despite its imperfections, this method used here has the advantage of being simple (to use and compare), robust, easily transposable to different scales and low cost. It shows the necessity to define policy recommendations in favor of the protection of pollinator insects (e.g., planting wild melliferous plant species) due to the high value of pollination service, particularly in the case of fruit crops. Yet, this value relates only to one aspect of the pollination service and therefore gives only a minimal value of it. It does not take into account for example its contribution to crop production not used for human consumption (forage and industrial crops, ornamentals), human health (essential micronutrients), pollinator patrimonial value (education, recreation, inspiration,…) or to wild plant species and landscapes conservation (