Enough Is Enough? Searching for the Optimal Sample Size to Monitor European Habitats: A Case Study from Coastal Sand Dunes
Abstract
:1. Introduction
2. Methods
2.1. Study Area and Sampling Design
2.2. Workflow of the Analysis
2.2.1. Description of Diversity Patterns
2.2.2. Species Composition Variation across Spatial Scales
2.2.3. Measurement of Multivariate Precision and Associated Dissimilarities (MultSE)
2.2.4. Effect of Sampling Size Reduction
3. Results
4. Discussion
4.1. Diversity Patterns Across Habitats and SACs
4.2. Spatial Variation of Reduced Dataset
4.3. The Lesson We Learned
5. Conclusions
- conduct pilot studies testing different sampling probabilistic methods;
- wisely plan sampling efforts taking into account resource availability (i.e., time and costs);
- approaches based on plant functional traits and remote sensing may provide novel insights on ecosystem functioning, the latter revealed to be also a cost-effective way to handle biodiversity measurements and to predict species changes through time.
Supplementary Materials
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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EUNIS Habitat | EU Habitat (Directive 92/43/EEC) | Target Species |
---|---|---|
Shifting coastal dunes (B1.3) | 2110- Embryonic shifting dunes | Ammophila arenaria, Anthemis maritima, Calystegia soldanella, Cyperus capitatus, Echinophora spinosa, Elymus farctus, Eryngium maritimum, Euphorbia peplis, Euphorbia paralias, Lotus creticus, L. cytisoides, Medicago marina, Othantus maritimus, Pancratium maritimum, Polygonum maritimum, Solidago litoralis, Sporobolus arenarius, Stachys maritima |
2120 -Shifting dunes along the shoreline with Ammophila arenaria (white dunes) | ||
Coastal stable dune grassland (B1.4) | 2210 -Fixed coastal dunes with herbaceous vegetation (grey dunes) | Anthemis mixta, Bromus diandrus, Corrigiola telephifolia, Corynephorus divaricatus, Crucianella maritima, Cutandia maritima, Daucus pumilus, Eva xpygmaea, Helichrysum stoechas, Lagurus ovatus, Lupinus angustifolius, Malcolmia ramosissima, Maresia nana, Matthiola tricuspidata, Medicago littoralis, Ononis variegata, Pancratium maritimum, Phleum arenarium, Polycarpon diphyllum, Pseudorlaya pumila, Pycnocomon rutifolium, Seseli tortuosum, Silene canescens, S. gallica, S. niceensis, Sonchus bulbosus, Thesium humile, Vulpia fasciculata |
2230 - Malcolmietalia dune grasslands | ||
Coastal dune scrub (B1.6) | 2230 -Malcolmietalia dune grasslands 2240 -Brachypodietalia dune grasslands with annuals 2250* - Coastal dunes with Juniperus spp. | Aetheorhiza bulbosa, Aira elegans, Andryala integrifolia, Anthyllis barba-jovis, Asparagus acutifolius, Brachypodium distachyum, Briza maxima, Clematis flammula, Corynephorus divaricatus, Corrigiola telephifolia, Cutandia maritima, Evax pygmaea, Galium divaricatum, Juniperus communis, Juniperus macrocarpa, J. turbinata, Lagurus ovatus, Lonicera implexa, Lotus angustissimus, Lupinus angustifolius, Malcolmia ramosissima, Maresia nana, Matthiola tricuspidata, Medicago littoralis, Myrtus communis, Ononis variegata, Ornithopus compressus, Phillyrea angustifolia, P. latifolia, Phleum arenarium, Pistacia lentiscus, Polycarpon diphyllum, Plantago lagopus, P. bellardii, Prasium majus, Pseudorlaya pumila, Rhamnus alaternus, Rubia peregrina, Rumex bucephalophorus, Ruscus aculeatus, Silene canescens, S. nicaensis, S. gallica, Smilax aspera, Tuberaria guttata, Vulpia membranacea |
Term | Levels | Name | Area (Ha) | N° Plots | Average Richness (Min-Max) |
---|---|---|---|---|---|
HABITAT | B1.3 | Shifting coastal dunes | 54.70 | 54 | 7 (2–12) |
B1.4 | Stable dune grasslands | 121.94 | 124 | 10 (3–21) | |
B1.6 | Coastal dune scrubs | 42.33 | 28 | 9 (2–17) | |
SAC | TL | Torre del Lago | 81.26 | 83 | 11 (4–21) |
PU | Parco dell’Uccellina | 73.33 | 54 | 7 (3–12) | |
SP | SelvaPisana | 64.39 | 69 | 8 (2–17) | |
HABITAT:SAC | B1.3:PU | Shifting coastal dunes: Parco dell’Uccellina | 20.11 | 21 | 7 (3–12) |
B1.3:SP | Shifting coastal dunes: SelvaPisana | 19.26 | 17 | 6 (2–11) | |
B1.3:TL | Shifting coastal dunes: Torre del Lago | 15.32 | 16 | 8 (4–11) | |
B1.4:PU | Stable dune grasslands: Parco dell’Uccellina | 20.08 | 21 | 6 (3–11) | |
B1.4:SP | Stable dune grasslands: SelvaPisana | 40.96 | 38 | 8 (3–16) | |
B1.4:TL | Stable dune grasslands: Torre del Lago | 60.91 | 65 | 12 (6–21) | |
B1.6:PU | Coastal dune scrub: Parco dell’Uccellina | 33.14 | 12 | 8 (4–12) | |
B1.6:SP | Coastal dune scrub: Selva Pisana | 41.62 | 14 | 9 (2–17) | |
B1.6:TL | Coastal dune scrub: Torre del Lago | 5.03 | 2 | 12 (11–12) |
Source of Variation | df | MS | F | Variance Components (%) |
---|---|---|---|---|
Abundance | ||||
SAC | 2 | 14,817 | 6.17 *** | 15.58 |
Habitat | 2 | 42,946 | 17.86 *** | 25.68 |
SAC × Habitat | 4 | 8988 | 3.74 *** | 16.97 |
Residual | 197 | 2405 | 41.77 | |
Total | 205 | |||
presence/absence | ||||
SAC | 2 | 19,916 | 8.99 *** | 18.53 |
Habitat | 2 | 40,571 | 18.31 *** | 24.86 |
SAC × Habitat | 4 | 8653 | 3.91 *** | 16.70 |
Residual | 197 | 2215 | 39.91 | |
Total | 205 |
Levels | Name | Abundance | Presence/Absence |
---|---|---|---|
B1.3 | Shifting coastal dunes | 9 ± 0.3 | 10 ± 0.4 |
B1.4 | Stable dune grasslands | 25 ± 2.2 | 14 ± 0.4 |
B1.6 | Coastal dune scrubs | 7 ± 0.3 | 7 ± 0.3 |
TL | Torre del Lago | 12 ± 0.4 | 11 ± 0.4 |
PU | Parco dell’Uccellina | 9 ± 0.3 | 9 ± 0.4 |
SP | SelvaPisana | 10 ± 0.4 | 10 ± 0.4 |
B1.3:PU | Shifting coastal dunes: Parco dell’Uccellina | 6 ± 0.3 | 6 ± 0.3 |
B1.3:SP | Shifting coastal dunes: SelvaPisana | 5 ± 0.3 | 5 ± 0.3 |
B1.3:TL | Shifting coastal dunes: Torre del Lago | 5 ± 0.3 | 5 ± 0.3 |
B1.4:PU | Stable dune grasslands: Parco dell’Uccellina | 6 ± 0.3 | 6 ± 0.3 |
B1.4:SP | Stable dune grasslands: SelvaPisana | 8 ± 0.3 | 8 ± 0.3 |
B1.4:TL | Stable dune grasslands: Torre del Lago | 10 ± 0.4 | 10 ± 0.4 |
B1.6:PU | Coastal dune scrub: Parco dell’Uccellina | 4 ± 0.2 | 4 ± 0.2 |
B1.6:SP | Coastal dune scrub: Selva Pisana | 5 ± 0.3 | 5 ± 0.2 |
B1.6:TL | Coastal dune scrub: Torre del Lago | - | - |
Abundance | Presence/Absence | ||||||
---|---|---|---|---|---|---|---|
Term | Statistic | F | R2 | Rate of Significance (p < 0.05) | F | R2 | Rate of Significance (p < 0.05) |
SAC | Min. | 2.62 | 0.06 | 100% | 2.31 | 0.08 | 100% |
1st quart. | 3.86 | 0.09 | 3.11 | 0.10 | |||
Median | 4.31 | 0.01 | 3.38 | 0.10 | |||
3rd quart. | 4.77 | 0.11 | 3.65 | 0.11 | |||
Max. | 6.84 | 0.15 | 5.22 | 0.15 | |||
Habitat | Min. | 4.67 | 0.13 | 100% | 2.74 | 0.09 | 100% |
1st quart. | 7.20 | 0.19 | 4.03 | 0.13 | |||
Median | 8.11 | 0.21 | 4.47 | 0.14 | |||
3rd quart. | 9.06 | 0.23 | 4.93 | 0.15 | |||
Max. | 12.97 | 0.30 | 7.31 | 0.20 | |||
SAC × Habitat | Min. | 1.11 | 0.06 | 94.3% | 1.15 | 0.08 | 98.7% |
1st quart. | 1.67 | 0.09 | 1.53 | 0.10 | |||
Median | 1.88 | 0.01 | 1.67 | 0.10 | |||
3rd quart. | 2.13 | 0.11 | 1.83 | 0.11 | |||
Max. | 3.38 | 0.15 | 2.70 | 0.14 |
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Maccherini, S.; Bacaro, G.; Tordoni, E.; Bertacchi, A.; Castagnini, P.; Foggi, B.; Gennai, M.; Mugnai, M.; Sarmati, S.; Angiolini, C. Enough Is Enough? Searching for the Optimal Sample Size to Monitor European Habitats: A Case Study from Coastal Sand Dunes. Diversity 2020, 12, 138. https://doi.org/10.3390/d12040138
Maccherini S, Bacaro G, Tordoni E, Bertacchi A, Castagnini P, Foggi B, Gennai M, Mugnai M, Sarmati S, Angiolini C. Enough Is Enough? Searching for the Optimal Sample Size to Monitor European Habitats: A Case Study from Coastal Sand Dunes. Diversity. 2020; 12(4):138. https://doi.org/10.3390/d12040138
Chicago/Turabian StyleMaccherini, Simona, Giovanni Bacaro, Enrico Tordoni, Andrea Bertacchi, Paolo Castagnini, Bruno Foggi, Matilde Gennai, Michele Mugnai, Simona Sarmati, and Claudia Angiolini. 2020. "Enough Is Enough? Searching for the Optimal Sample Size to Monitor European Habitats: A Case Study from Coastal Sand Dunes" Diversity 12, no. 4: 138. https://doi.org/10.3390/d12040138