Research Article |
Corresponding author: Lars Pettersson ( lars.pettersson@biol.lu.se ) Academic editor: Romain Julliard
© 2016 Elin Videvall, Erik Öckinger, Lars Pettersson.
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:
Videvall E, Öckinger E, Pettersson LB (2016) Butterfly monitoring using systematically placed transects in contrasting climatic regions – exploring an established spatial design for sampling. Nature Conservation 14: 41-62. https://doi.org/10.3897/natureconservation.14.7497
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Butterfly monitoring schemes are recording programs initiated to monitor nationwide butterfly abundance and distribution patterns, often with help from volunteers. The method generates high-resolution data, but may be associated with a degree of habitat sampling bias if volunteers prefer to survey areas perceived to be high-quality butterfly habitats. This can result in habitats becoming underrepresented in the data set, leading to less information about the butterfly populations there. In the present study, we investigate the possibility of applying a spatial design used by the Swedish Bird Survey for nationwide, grid-based sampling, with a goal to get butterfly monitoring data covering a representative sample of different habitats. We surveyed four 2×2 km sampling squares, split into 100 m segments, in the southernmost region of Sweden (Scania) and four in the northernmost region (Norrbotten). The grid-based transects were compared with volunteer-selected transects in a GIS analysis using a refined Swedish version of CORINE land cover data to see how well these two transect designs represent true habitat coverage. A total of 53 km transect was monitored, resulting in 490 individuals and 29 different species recorded. We found that transect cover correlated significantly with overall land cover using both monitoring methods, though standardised transects outperformed volunteer-selected transects in habitat representation in Scania, but not in Norrbotten. Butterflies were found to aggregate significantly in specific habitats, but with contrasting results for the two geographically different regions. Grasslands in both regions generated a high number of recorded butterflies, although so did clear-cut and residential areas in Norrbotten as well. The highest number of individuals recorded per transect was found in bogs in Scania. This study emphasises the value of complementing free site selection monitoring schemes with spatially representative schemes such as the Swedish Bird Survey, and sheds some light on general habitat preferences for Swedish butterflies in two contrasting climatic regions.
Butterflies, monitoring, biodiversity, habitat, sampling, transects, boreal, continental, populations, GIS, CORINE
Butterflies are the most widely studied of all insect groups (
Habitat loss and fragmentation is a major driver behind the decline of many butterfly species worldwide (
In order to effectively monitor population trends, butterfly monitoring schemes now run in several European countries, e.g. the UK, Finland, Germany and the Netherlands (
In the UK, species that are widespread across the general countryside compromise half of the butterfly fauna (
The Swedish Butterfly Monitoring Scheme is a nationwide program with free site selection (
A Map over Sweden with systematically placed bird monitoring squares throughout the country, used by the Swedish Bird Survey. The two regions featured in this study are shown, with monitoring squares visited portrayed in red. The squares are 2×2 km wide, indicate location, and not shown to scale B Example map of a bird monitoring square: site Kongaö in Scania, Sweden, indicated as a red, 2×2 km square. Butterfly transects followed the periphery of bird monitoring squares (N = 8 sites) as closely as possible for as long as weather conditions and time of day permitted (
With this study we have a twofold goal. The first is to evaluate if the large-scale, grid-based method used by the Swedish Bird Survey can be adapted and applied to butterfly monitoring. The second aim is to use the collected data to quantify butterfly abundance in relation to habitat characteristics in two contrasting climatic regions of Sweden: Scania and Norrbotten.
While transects based on standardised grid-based designs are generally assumed to outperform free site selection in terms of true habitat representation, this assumption is rarely evaluated. Here, we quantified land cover in the Swedish Bird Survey transects visited in the present experiment (N = 4 in each region, total length: 32 km per region) as well as land cover in volunteer-selected free transects in the same regions (N = 5 in each region, total length 12.92 km in Scania and 12.22 km in Norrbotten). The free transects that were analysed comprised all sites in Norrbotten and a random, corresponding subsample of the transects in Scania. The free transects that we analysed covered less distance that the standardised transects and hence had smaller areas. To allow direct comparison despite differing total areas, we recalculated land cover to the smallest area (free transects, Scania: 4.45 km2 ; Appendix: Table
Butterfly monitoring took place during the summer of 2010 from June 17 to July 7 in Scania, the southernmost part of Sweden, and from July 20-28 in Norrbotten, the northernmost part of Sweden. Each site consisted of the four outer sections of 2×2 km squares used by the Swedish Bird Survey (Figure
All transects monitored were divided into segments of approximate 100 m length with an accompanying description for the habitat surrounding the transects. The distance of the transect segments were estimated with the help of maps. The different habitat categories were: deciduous forest, coniferous forest, grassland, residential area, fen/bog, and clear-cut area (examples of three habitats can be seen in Figure
Examples of butterfly habitat categories: A coniferous forest in Rosfors (Norrbotten) B grassland in Hyby (Scania), and C deciduous forest in Slätteberga (Scania). Photos by Elin Videvall.
Recordings were made of all butterflies (Rhopalocera) and burnet moths (Zygaenidae), as seen within an ‘invisible box’ of 5 m in front of the recorders, 2.5 m to each side and 5 m above, according to the ‘Pollard walk’ method (
For each region, we evaluated similarity in habitat coverage between the region as a whole and the two transect approaches using Spearman Rank Correlation tests within each region followed by two-sample tests of correlation coefficients using Fisher z-transformed values (
Butterfly data was compiled using values per 100 m segment as the basis for calculations. To quantify biodiversity, we used the Simpson’s Diversity Index (
where ni = the number of individuals in the ith species, N = the total number of individuals and S = the number of species in the sample. We represent this biodiversity measurement as 1/D, called the Simpson’s Reciprocal Index. In this variant of D, 1 is the lowest possible value, representing a community containing only one species, and the maximum possible value is the number of species in the sample (
Alpha (α) diversity generally measures species diversity of a defined area or habitat, whereas beta (β) diversity is used as a measure of the difference between two or more defined areas (
Chi-square tests of butterfly abundance were performed for each habitat category, to test if butterfly distributions differed from random expectations, i.e. if individuals distributed among habitat categories according to their relative coverage along the transects. All statistical analyses were performed in R (v. 2.15, R Core Team 2013).
The land cover representation of the Swedish Bird Survey transects and the volunteer-selected transects correlated significantly with overall land cover within Scania (SMD land cover classes: SBS transects: r = 0.890, N = 14, p < 0.001; in free transects: r = 0.524, N = 16, p = 0.04, Appendix: Table
The systematically placed 2×2 km squares used by the Swedish Bird Survey correspond to 8 km butterfly transect per site (80 segments). In total we monitored 53 km transect (83%) out of the 64 km transect present in the eight squares combined. Using transects along the borders of Bird Survey squares proved to be slightly more than what was normally possible to cover within one day of butterfly recording. The landscape along the transects was sometimes difficult to traverse, and some parts of the transects were completely inaccessible. The overall distance monitored in the two regions was very similar, with 27 km in Scania and 26 km in Norrbotten. Even though some of the squares were not completely surveyed, we got a substantial amount of data with an average of 6.6 km transect monitored per site.
Field estimates of total habitat coverage was divided fairly equal between deciduous forest (25%), coniferous forest (26%), and grassland (30%), among all transects monitored (Figure
A Transect monitored (km) in different habitats for two geographically different regions in Sweden: the southernmost region, Scania, and the northernmost region, Norrbotten B Number of butterfly individuals recorded per 100 m transect in different habitats (mean values ± SE). Numbers in parentheses indicate total number of individuals monitored per habitat (non-integers due to proportional habitat coverage per 100 m transect) C Total number of butterfly species recorded in the different habitats.
A total of 490 butterfly individuals were recorded, with 250 counted in Scania (9.3 individuals per km transect) and 240 in Norrbotten (9.2 individuals per km transect). We recorded 29 different butterfly species (Appendix: Table
Butterfly abundance in different habitats was compared to the expected number of individuals relative to habitat coverage in each region (Table
Butterfly abundance in different habitats for two geographically different Swedish regions, Scania and Norrbotten.
Number of individuals recorded | Mean nr of individuals per 100 m | χ2-value | p-value | Significance |
Abundance relative to expected value | |
---|---|---|---|---|---|---|
Scania | ||||||
Deciduous forest | 49.4 | 0.4 | 24.2 | < 0.001 | *** | Lower |
Coniferous forest | 22.9 | 1.0 | 0.07 | 0.787 | ns | No difference |
Clear-cut area | 8.0 | 1.7 | 1.1 | 0.286 | ns | No difference |
Grassland | 136.1 | 1.4 | 8.4 | 0.004 | ** | Higher |
Residential area | 5.6 | 0.3 | 5.7 | 0.017 | * | Lower |
Fen/bog | 28.0 | 7.6 | 19.2 | < 0.001 | *** | Higher |
Norrbotten | ||||||
Deciduous forest | 8.2 | 0.7 | 0.48 | 0.488 | ns | No difference |
Coniferous forest | 28.6 | 0.3 | 45.8 | < 0.001 | *** | Lower |
Clear-cut area | 35.7 | 2.0 | 6.7 | 0.009 | ** | Higher |
Grassland | 117.8 | 2.0 | 24.2 | < 0.001 | *** | Higher |
Residential area | 47.7 | 1.8 | 6.9 | 0.008 | ** | Higher |
Fen/bog | 2.0 | 0.07 | 20.2 | < 0.001 | *** | Lower |
In Norrbotten, we found a significantly higher number of individuals in clear-cut areas (χ2 = 6.73, p = 0.009) and in residential areas (χ2 = 6.94, p = 0.008) than expected, but not in the clear-cut areas of Scania (χ2 = 1.14, p = 0.286), and in Scania’s residential areas we even recorded significantly fewer individuals than expected (χ2 = 5.71, p = 0.017) (Table
The habitat with highest number of species recorded in total was grassland, with 16 different species recorded in Scania and 12 species in Norrbotten, however this might be partly due to relatively high coverage of grassland monitored, with 10 km grassland visited in Scania (37%), and 5.8 km in Norrbotten (22.3%) (Figure
Species richness in different habitats in two geographically different Swedish regions, Scania and Norrbotten.
Number of species recorded |
χ2-value | p-value | Significance |
Diversity relative to expected value | |
---|---|---|---|---|---|
Scania | |||||
Deciduous forest | 12 | 0.21 | 0.644 | ns | No difference |
Coniferous forest | 10 | 5.59 | 0.018 | * | Higher |
Clear-cut area | 3 | 2.05 | 0.152 | ns | No difference |
Grassland | 16 | 2.57 | 0.109 | ns | No difference |
Residential area | 6 | 2.72 | 0.099 | ns | No difference |
Fen/bog | 4 | 3.18 | 0.074 | ns | No difference |
Norrbotten | |||||
Deciduous forest | 5 | 3.14 | 0.076 | ns | No difference |
Coniferous forest | 11 | 0.81 | 0.369 | ns | No difference |
Clear-cut area | 9 | 6.11 | 0.013 | * | Higher |
Grassland | 12 | 4.58 | 0.032 | * | Higher |
Residential area | 5 | 1.65 | 0.199 | ns | No difference |
Fen/bog | 2 | 0.02 | 0.880 | ns | No difference |
The biodiversity in the two regions was measured using the Simpson Reciprocal Diversity Index (1/D) and the Simpson Evenness Index (1/DS). The Simpson Reciprocal Index for Scania (6.86) was slightly higher (although non-significantly) than the index for Norrbotten (5.10) (this difference was tested between the sites using a Wilcoxon rank sum test: W = 12, p = 0.31). The Simpson Evenness Index for Scania (0.31), was similar and not significantly different than the corresponding number for Norrbotten (0.32) (tested between the sites with a Wilcoxon rank sum test: W = 11, p = 0.47).
The mean species number within a region, the α diversity, did not differ significantly between Scania and Norrbotten (Wilcoxon rank sum test: W = 10, p = 0.661). The β diversity, defined here as the mean difference in species number between each site and the total species number of that region, was significantly higher in Scania than in Norrbotten (Wilcoxon rank sum test: W = 16, p = 0.028).
In this study we have tested the possibility of using systematically placed transects in butterfly monitoring schemes in order to get butterfly recordings with reduced volunteer habitat bias. Volunteer recorders are most often free to select the location for monitoring (
Our GIS analyses showed that standardised transects mirrored overall land cover better than free transects in Scania, but not significantly better in Norrbotten. The Norrbotten landscape is generally less urbanised than Scania (cf. Appendix: Table
We found that the transects used by the Swedish Bird Survey provided good coverage of traditionally underrepresented butterfly habitats such as forests, clear-cuts and wetlands in both regions (Figure
During the year that the present study was performed, there were still relatively few free transects in Scania and Norrbotten and a direct comparison of simultaneously collected butterfly recordings from multiple standardized and free transects was not possible. Now substantially more free transects are monitored and such a direct comparison of observations made throughout the season would be a logical next step.
We found major differences in butterfly abundance and species richness in the different habitats and between the two regions. In grasslands, we found more butterfly individuals than expected in both regions (Table
The clear-cut and residential areas in Norrbotten harboured more butterfly individuals than expected, but not in Scania; this region had instead significantly fewer individuals recorded in residential areas (Table
The β diversity was significantly different between the regions Scania and Norrbotten, indicating that the sites in Norrbotten harboured many of the same species, as opposed to Scania where the sites often had different species composition. This is most likely because Norrbotten has a smaller species pool compared to Scania, which harbours several rare and local butterfly species (
Some butterfly species that we recorded in Scania were not seen in Norrbotten (N = 13), and in Norrbotten 6 out of 16 species were not found in Scania. This is likely due to the climate differences resulting in different species distributions, but it is also plausible that many species were not detected by chance. We monitored the two regions intentionally during different dates to take into account their differences in spring arrival. Recordings in Scania were performed between June 17th and July 7th, and recordings in Norrbotten in late July (20th – 28th). Because of the large latitudinal differences between the regions (Appendix: Table
A ‘reduced effort’ monitoring scheme is based on a higher number of transects and counted only a few times per year, as opposed to the more traditional scheme, which are to a greater extent based on more regular visits and free site selection (
A Swedish butterfly monitoring scheme with systematically placed transects throughout the country with the intention to cover different habitats would produce a representative picture of the nation’s butterfly population without introducing bias from habitat choice by the recorder. Free and systematic site selection should however not be seen as mutually exclusive. The Swedish Bird Survey started with free site selection in 1969 and added its grid-based network of geographically representative transects to the monitoring scheme in 1996. Similarly, the UK butterfly monitoring scheme has added a complementary, Wider Countryside monitoring scheme (
Following this, we suggest that it would be valuable to complement monitoring schemes with free site selection such as the Swedish butterfly monitoring by adding standardised, grid-based sampling schemes. An exciting possibility resulting from joint monitoring of different organisms in a grid-based design is that more general biodiversity trends such as those indicated by
We would like to thank the co-recorders participating in this study: Elisabeth Arvidsson for monitoring assistance in Scania, Anneli Sandström and Daniel Moberg for monitoring assistance in Norrbotten. We are also grateful to The Entomological Society of Lund (ESIL) for funding EV with materials used in this study, and to Åke Lindström and Martin Stjernman for providing the Swedish Bird Survey maps. Tobias Roth acted as reviewer for this manuscript and provided valuable comments on a previous version. LP is funded by the Swedish Environmental Protection Agency as part of the Swedish Butterfly Monitoring Scheme.
Geographical coordinates (Swedish grid, RT 90 2.5 gon V) for butterfly monitoring sites.
Site | Municipality | Region | Recording | Latitude (N) | Longitude (E) |
---|---|---|---|---|---|
Hyby | Svedala | Scania | 2010-06-17 | 55.5595° | 13.2235° |
Tjörnarp | Höör | Scania | 2010-06-24 | 56.0170° | 13.5922° |
Slätteberga | Tomelilla | Scania | 2010-06-29 | 55.7985° | 14.0016° |
Kongaö | Svalöv | Scania | 2010-07-07 | 56.0089° | 13.1913° |
Sundom | Luleå | Norrbotten | 2010-07-20 | 65.7750° | 22.0709° |
Rosfors | Piteå | Norrbotten | 2010-07-23 | 65.5780° | 21.4869° |
Långberget | Boden | Norrbotten | 2010-07-24 | 65.8021° | 21.5372° |
Bergnäset | Luleå | Norrbotten | 2010-07-28 | 65.5614° | 22.0342° |
English name | Scientific name | Scania | Norrbotten | Total |
---|---|---|---|---|
Large Skipper | Ochlodes sylvanus | 59 | 4 | 63 |
Black-veined White | Aporia crataegi | 2 | 0 | 2 |
Large White | Pieris brassicae | 2 | 0 | 2 |
Green-veined White | Pieris napi | 7 | 2 | 9 |
Moorland Clouded Yellow | Colias palaeno | 0 | 1 | 1 |
Brimstone | Gonepteryx rhamni | 6 | 1 | 7 |
Idas Blue | Plebejus idas | 0 | 10 | 10 |
Cranberry Blue | Plebejus optilete | 24 | 12 | 36 |
Silvery Argus | Aricia nicias | 0 | 10 | 10 |
Amanda’s Blue | Polyommatus amandus | 2 | 1 | 3 |
Common Blue | Polyommatus icarus | 6 | 2 | 8 |
Scarce Copper | Lycaena virgaureae | 0 | 49 | 49 |
Green Hairstreak | Callophrys rubi | 1 | 0 | 1 |
Dark Green Fritillary | Argynnis aglaja | 0 | 3 | 3 |
High Brown Fritillary | Argynnis adippe | 0 | 1 | 1 |
Lesser Marbled Fritillary | Brenthis ino | 10 | 9 | 19 |
Pearl-bordered Fritillary | Boloria euphrosyne | 1 | 0 | 1 |
Small Pearl-bordered Fritillary | Boloria selene | 16 | 1 | 17 |
Map Butterfly | Araschnia levana | 2 | 0 | 2 |
Red Admiral | Vanessa atalanta | 1 | 0 | 1 |
Peacock Butterfly | Aglais io | 6 | 0 | 6 |
Small Tortoiseshell | Aglais urticae | 7 | 49 | 56 |
Heath Fritillary | Melitaea athalia | 2 | 0 | 2 |
Speckled Wood | Pararge aegeria | 1 | 0 | 1 |
Wall Brown | Lasiommata megera | 1 | 0 | 1 |
Large Wall Brown | Lasiommata maera | 1 | 0 | 1 |
Small Heath | Coenonympha pamphilus | 16 | 0 | 16 |
Ringlet | Aphantopus hyperantus | 51 | 0 | 51 |
Arran Brown | Erebia ligea | 0 | 69 | 69 |
Unknown Black | 1 | 0 | 1 | |
Unknown White | 7 | 2 | 9 | |
Unknown Blue | 6 | 8 | 14 | |
Unknown Orange | 12 | 6 | 18 | |
Total number of individuals: | 250 | 240 | 490 | |
Total number of species: | 22 | 16 | 29 |
Land cover information for sites in the two regions: a) area in km2 for Scania and Norrbotten as a whole, for Swedish Butterfly Monitoring Scheme (free) transects (N = 5 in each region), and Swedish Bird Survey (standardised) transects (see Supplementary Material Table
Scania | Norrbotten | ||||||||
---|---|---|---|---|---|---|---|---|---|
Total area | Free transects | Standardised transects | Total area | Free transects | Standardised transects | ||||
a) | 15995 | 4.45 | 12.80 | 33570 | 4.52 | 12.80 | |||
b) | |||||||||
Code | CLC Code | SMD Code | CLC/SMD Description | ||||||
1 | 1.1.1 | 1.1.1 | Continuous urban fabric | 0.028 | 0.0078 | ||||
2 | 1.1.2 | 1.1.2.1.1 | Discontinuous urban fabric, > 200 inhabitants and limited green areas | 0.46 | 0.76 | 0.047 | |||
3 | 1.1.2 | 1.1.2.1.2 | Discontinuous urban fabric, > 200 inhabitants and larger green areas | 1.6 | 0.73 | 0.22 | 2.4 | ||
4 | 1.1.2 | 1.1.2.2 | Discontinuous urban fabric, < 200 inhabitants | 0.27 | 0.79 | 0.070 | 1.4 | ||
5 | 1.1.2 | 1.1.2.3 | Solitary houses and farm yards | 0.10 | 0.58 | 0.10 | 0.94 | 1.8 | |
6 | 1.2.1 | 1.2.1 | Industrial or commercial units | 0.47 | 2.9 | 0.10 | |||
7 | 1.2.2 | 1.2.2 | Road and rail networks and associated land | 0.14 | 0.0076 | ||||
8 | 1.2.3 | 1.2.3 | Port areas | 0.10 | 0.0022 | ||||
9 | 1.2.4 | 1.2.4 | Airports | 0.092 | 0.019 | ||||
10 | 1.3.1 | 1.3.1.1 | Sand and gravel pits | 0.048 | 0.028 | 0.21 | |||
11 | 1.3.1 | 1.3.1.2 | Other mineral extraction sites | 0.044 | 3.8 | 0.0045 | |||
12 | 1.3.2 | 1.3.2 | Dump sites | 0.035 | 0.0068 | ||||
13 | 1.3.3 | 1.3.3 | Construction sites | 0.015 | |||||
14 | 1.4.1 | 1.4.1 | Green urban areas | 0.76 | 0.11 | 0.43 | |||
15 | 1.4.2 | 1.4.2.1 | Sport facilities, shooting grounds etc | 0.12 | 0.021 | ||||
16 | 1.4.2 | 1.4.2.2 | Airfields (grass) | 0.0013 | 0.0015 | ||||
18 | 1.4.2 | 1.4.2.4 | Golf courses | 0.22 | 3.6 | 0.010 | |||
19 | 1.4.2 | 1.4.2.5 | Non-urban parks | 0.087 | 3.1 | 1.7 | 0.0079 | ||
20 | 1.4.2 | 1.4.2.6 | Camping sites and holiday cottages | 0.094 | 0.011 | ||||
30 | 2.1.1 | 2.1.1 | Non-irrigated arable land | 31 | 43 | 16 | 1.4 | 19 | 9.6 |
31 | 2.2.2 | 2.2.2 | Fruit trees and berry plantations | 0.15 | 0.0017 | ||||
32 | 2.3.1 | 2.3.1 | Pastures | 5.9 | 14 | 8.4 | 1.0 | 2.8 | 0.57 |
40 | 3.1.1 | 3.1.1.1 | Broad-leaved forest, not on mires or bare rock | 8.7 | 18 | 40 | 2.1 | 3.4 | 2.0 |
41 | 3.1.1 | 3.1.1.2 | Broad-leaved forest on mires | 0.21 | 2.6 | 0.74 | 3.3 | 0.76 | |
43 | 3.1.2 | 3.1.2.1.1 | Coniferous forest, lichen dominated forest floor | 3.6 | 0.53 | 5.4 | |||
56 | 3.1.2 | 3.1.2.1.2 | Coniferous forest, not on lichen dominated forest floor | 3.3 | 1.3 | 3.1 | 16 | 20 | 17 |
44 | 3.1.2 | 3.1.2.1.2.1 | Coniferous forest, 7-15 m | 6.7 | 3.4 | 7.7 | 10 | 12 | 18 |
45 | 3.1.2 | 3.1.2.1.2.2 | Coniferous forest, >15 m | 1.2 | 3.0 | 3.6 | 0.042 | 1.3 | |
46 | 3.1.2 | 3.1.2.2 | Coniferous forest on mire | 0.0026 | 0.63 | 1.2 | 2.7 | ||
47 | 3.1.2 | 3.1.2.3 | Coniferous forest on bare rock | 1.771 | 2.9 | 3.29 | 7.4 | 10 | 8.7 |
48 | 3.1.3 | 3.1.3.1 | Mixed forest, not on mires or bare rock | 0.17 | 0.65 | 1.2 | 0.84 | 0.034 | |
49 | 3.1.3 | 3.1.3.2 | Mixed forest on mire | 0.00059 | |||||
50 | 3.1.3 | 3.1.3.3 | Mixed forest on bare rock | 0.022 | 0.082 | ||||
51 | 3.2.1 | 3.2.1 | Natural grassland | 0.038 | 0.015 | ||||
52 | 3.2.2 | 3.2.2 | Moors and heathland | 0.11 | 0.13 | 0.042 | |||
53 | 3.2.4 | 3.2.4.1 | Thickets | 1.7 | 1.2 | 6.3 | 6.3 | 0.83 | 7.7 |
54 | 3.2.4 | 3.2.4.2 | Clear-cuts | 2.1 | 3.9 | 3.5 | 11 | 14 | 8.8 |
58 | 3.3.1 | 3.3.1 | Beaches, dunes, and sand plains | 0.047 | 0.032 | ||||
59 | 3.3.2 | 3.3.2 | Bare rock | 0.010 | 0.013 | ||||
70 | 4.1.1 | 4.1.1 | Inland marshes | 0.12 | 0.16 | 0.25 | 0.19 | ||
71 | 4.1.2 | 4.1.2.1 | Wet mires | 0.049 | 0.069 | 1.6 | |||
72 | 4.1.2 | 4.1.2.2 | Other mires | 0.49 | 13 | 1.1 | 2.3 | ||
73 | 4.1.2 | 4.1.2.3 | Peatbogs | 0.13 | 0.022 | ||||
74 | 4.2.1 | 4.2.1 | Salt marshes | 0.0032 | 0.0057 | ||||
80 | 5.1.1 | 5.1.1 | Water courses | 0.043 | 0.80 | ||||
81 | 5.1.2 | 5.1.2.1 | Water bodies, open | 1.8 | 0.34 | 3.0 | 4.1 | 13 | |
82 | 5.1.2 | 5.1.2.2 | Water bodies, closing vegetation | 0.072 | 0.044 | 0.50 | 0.010 | ||
83 | 5.2.1 | 5.2.1 | Coastal lagoons | 0.0074 | 0.057 | ||||
84 | 5.2.2 | 5.2.2 | Estuaries | 0.0059 | 0.40 | ||||
85 | 5.2.3 | 5.2.3.1 | Sea and ocean, open | 29 | 16 | 0.91 | |||
86 | 5.2.3 | 5.2.3.2 | Sea and ocean, closing vegetation | 0.012 | 0.0094 |