Journal of Threatened Taxa | www.threatenedtaxa.org | 26
January 2022 | 14(1): 20311–20322
ISSN 0974-7907
(Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.6664.14.1.20311-20322
#6664 | Received 03
September 2020 | Final received 22 December 2021 | Finally accepted 31 December
2021
Estimating the completeness of orchid checklists and
atlases: a case study from southern Italy
Antonio Croce
GIROS (Gruppo Italiano per la ricerca sulle Orchidee
Spontanee- Italian Group for the Research on Wild
Orchids), Via Chiesa - Tuoro, 44 - 81057 Teano, Caserta, Italy.
antocrx@gmail.com
Editor: Anonymity requested. Date of
publication: 26 January 2022 (online & print)
Citation: Croce,
A. (2022). Estimating the completeness of orchid checklists and
atlases: a case study from southern Italy. Journal of Threatened
Taxa 14(1): 20311–20322. https://doi.org/10.11609/jott.6664.14.1.20311-20322
Copyright: © Croce 2022. Creative
Commons Attribution 4.0 International License.
JoTT allows unrestricted use, reproduction,
and distribution of this article in any medium by providing adequate credit to
the author(s) and the source of publication.
Funding: None.
Competing interests: The author declares no
competing interests.
Author details: Antonio Croce earned a PhD in Applied Biology
from the University of Naples “Federico II” in 2007 and he has worked as a
research fellow or independent researcher on plant biodiversity and conservation,
with a focus on Mediterranean orchids. He is currently a high school Science
teacher and a member of GIROS, the Italian Group for the Research on Wild
Orchids.
Acknowledgements: I would like to
thank Prof. Giovanni Scopece,
Department of Biology, University of Naples “Federico II”, for his suggestions
and encouragement. I would also thank an anonymous reviewer for her/his
valuable comments.
Abstract: Checklists and
atlases are important tools for knowledge of the biodiversity of a geographic
unit. Nevertheless, they often suffer from bias due to preferential sampling.
It is important to assess the level of completeness of the data collected during
such research to allow comparison of the biodiversity of different areas, or to
use them for macroecology, biogeography or conservation purposes. This assessment is not trivial, especially when information from
heterogeneous sources is used (e.g., herbaria specimens, field observations,
literature data). The author suggests some simple methods to assess the completeness of floristic database and to represent the distribution of
the completeness at a scale level appropriate to the size of the studied area
or, on another hand, to the precision level of the available data. Such
information is useful to direct the surveys identifying less explored areas or
habitats and thereby correcting the sampling biases. Adding information about sampling effort or completeness could be very
useful to make floristic research more objective.
Keywords: European orchids,
floristic studies, sampling effort, species richness estimators, completeness,
citizen science.
Riassunto: le checklist
e gli atlanti floristici sono strumenti importantissimi per la conoscenza della
biodiversità. Tuttavia essi sono realizzati senza un design sperimentale e sono
soggetti a bias dovuto soprattutto al campionamento
preferenziale. E’ comunque importante, soprattutto quando questi studi si basano
su informazioni derivanti da fonti eterogenee (campioni d’erbario, osservazioni
in campo, dati bibliografici, ecc.) valutare il loro grado di completezza per
poter confrontare la biodiversità di diverse aree geografiche o per eseguire
analisi macroecologiche, biogeografiche e per la
valutazione dello stato di conservazione. L’autore propone alcuni semplici
metodi per stimare l’esaustività dei dati floristici, rappresentare la
distribuzione della completezza a scale adeguate da una parte alla dimensione
dell’area oggetto di studio e dall’altra al livello di precisione dei dati a
disposizione. Tali informazioni sono utili anche per orientare le ricerche nel
territorio, individuando aree o habitat meno esplorati e correggendo i bias di campionamento. L’aggiunta di informazioni sullo
sforzo di campionamento e la completezza delle ricerche può essere utile a
conferire agli studi floristici di base una maggiore oggettività.
INTRODUCTION
Floristic inventories or check lists and
atlases are important tools for assessing biodiversity and addressing its
conservation (Vallet et al. 2012). They are often the
result of careful and time-consuming researches conducted in specific
geographic units, focused on vascular plants or on smaller taxonomic group such
as Orchidaceae, one of the largest and most
widespread family of flowering plants (Dressler 1981; WCSPF 2019). The presence
and distribution of species of this family have been assessed at different
scales as most of them are rare, threatened or endangered (Cribb et al. 2003).
A checklist is a “card collection” aiming at listing all the taxa belonging to
the studied taxonomic group and reporting whether they are observed, collected
or reported in literature for a given area (e.g., Mathew & George 2015;
Aung et al. 2020; Popovich et al. 2020). The taxa are typically identified at
species or subspecies level, some sites of growth are reported together with
other information on the habitats, variety, rarity, ecology, chorology,
systematic or taxonomic issues. Atlases are more focused on the geographic
distribution of the taxa, instead. To be accomplished they require a field work
aiming not only at listing all the different taxonomic entities, but also at
detecting as more sites of growth as possible for each taxon. The result of
such work is a checklist with cartographic references or distribution maps and,
sometimes, their elaborations (e.g., Crain & Fernández 2020; Efimov 2020). Due to the long time needed for exhaustive
surveys, at a local scale this kind of research is increasingly carried out by non academics, the so called ‘citizen scientists’. This is
particularly true for the inventories and atlases of the European terrestrial
orchids, often published in specialized journals (e.g., Galesi
& Lorenz 2010; Frangini et al. 2019; Katopodi & Tsiftsis 2019;
Marrero et al. 2019).
The huge amount of work, even when results in
detailed distribution maps, almost never follows an experimental design, and
currently data are affected by bias caused by a preferential sampling approach,
e.g., data collector tends to sample protected areas or to collect more data
along the roads (Croce & Nazzaro 2017). Furthermore, none of the above mentioned
floristic studies is usually provided with a clear reference to the sampling
effort or to the level of completeness of the surveys. The absence of a
repeatable background and of a standardized approach is not a trivial issue, as
such collections of data are of great value for macroecology, ecology,
biogeography or conservation research (Soberón et al.
2000, 2007; Rocchini et al. 2011; Weigelt
et al. 2020).
In order to make inventories and atlases useful
tools for biogeographical or ecological research it is thus necessary to take
into account these issues and support floristic works with appropriate measures
of the degree of uncertainty (Rocchini et al. 2011).
In the same context, maps of floristic richness should be accompanied by maps
of knowledge, “maps of ignorance” or maps of completeness. These can be
realized considering that the number of species (namely the species richness)
recorded in a given period and in a given area is partial and lower than the
real number of species present (Gotelli & Colwell
2011). The more the sample effort increases the more the number of observed
species approaches the
theoretical, real number of species. On
the contrary, a sampling activity carried over a too long time could detect the
species turnover (e.g., for habitat change due to socio-economic or ecological
reasons or for climate changing) resulting in an overestimation of the number
of species than the existing habitats could theoretically host in a given time.
The real floristic richness and its distribution in an area can be estimated
with different methods (Gotelli & Colwell 2001; Vallet et al 2012). The most suitable for the kind of data
recorded in the field by orchidologists is the use of
‘sample based species rarefaction-curves’ (Gotelli
& Colwell 2001). Given that the sampling order in an area is not important,
data are resampled and curves are built. While the shape of accumulation curves
depends upon the order in which the samples are considered, the rarefaction
curves show smoother lines facilitating the comparison among entire datasets or
subsets. A species rarefaction curve is plotted starting from the mean number of
species of the smallest sample size. Then the mean number of species is
calculated for all combinations of the next sample size (i.e., the mean number
of species of two random samples, then three random samples, etc.).
This paper analyzes
some typical aspects of local scale inventories and atlases hitherto neglected.
Here, we propose simple approaches, accessible even for the non-academic,
citizen scientists to answer the following specific questions:
i. How can the richness of a floristic database
be assessed and how can different database be compared?
ii. Which richness estimator is more suitable
for terrestrial European orchids, given its intrinsic difficulties of
observation in field?
iii. When is the sampling of an area
sufficiently complete?
iv. How can completeness maps be realised and
how they can be useful to identify where to address further explorations?
MATERIALS AND METHODS
Source of the data and study areas
We used three datasets reporting the presence of orchids in three areas
in southern Italy, in northern Campania region, (Figure 1; Table 1) about 50 km
north of Naples and 150 south of Rome. The first dataset includes 3,046 records collected from 1996 to 2019 on
the Roccamonfina volcano (Croce & Nazzaro 2012 and following observations). It covers an area
of about 210 km2 and lists 46 taxa (species and subspecies). The
second dataset consists of 278 records collected from 2002 to 2005 on the
little limestone mountain range of Vairano Patenora and Pietravairano
municipalities (Croce 2012 and following observations), hereafter called “Vairanese”. It covers an area of 17 km2 and
lists 32 taxa. The third dataset consists of 305 records collected mainly in
2005 and then from 2013 to 2019 on the limestone mountain ranges of the western
Matese area, hereafter called “W–Matese”.
It covers an area of 20 km2 and lists 33 taxa.
Data collection
Only the observations geolocated with a precision level lower than 100 m
(punctual data according to Croce & Nazzaro 2017) were included in the analysis. Nomenclature was revised and, when needed, standardised and hybrids were excluded
from the analysis. To avoid the oversampling bias
(i.e., a single population of plants sampled in different sampling units) the
records have been clumped to represent the presence of the taxa in 100 x 100 m
squares, connected to the geographic grid of the used coordinates system (WGS
84 / UTM zone 33N, EPSG 32633). Each sampling unit (plot) is univocally
identified, therefore, by the geographic position of the square and by the
sampling date so that two sampling activities that took place in two different
date but inside the same square have been considered as two different plots. In
this way, I take into account the sampling effort in terms of time, very
important for species requiring observations at different times to be correctly
observed and identified. In the end I get, for each dataset, a matrix taxon ×
plot that I used for the elaborations and further analysis.
Data analysis
To compare the three datasets in terms of sampling effort and observed
specific richness (Sobs), I have mapped the specific richness for
each area using a grid with 1 km2 resolution (i.e., 1 x 1 km UTM
cells) intersecting the study areas (i.e., the three geographic units as
defined above) and calculating both the number of plots and the number of
observed species in each cell. A regression analysis between the number of
plots and the number of species per each cell has been performed to correlate
the sampling effort to the observed species richness and therefore to validate
the density of plots as an indicator of the sampling effort. Then for each area
I built a sample-based rarefaction curve using the plots as samples. The curves
have been limited to the lower number of plots in the three datasets for a
better comparison of the observed species richness and its pattern among the
three studied areas. Being drawn with resampling statistical methods, the
curves allow the calculation of the 95% confidence limits or the standard
deviations.
Among the methods used to estimate the species richness of an area
starting from presence-absence data, the most appropriate for floristic
inventories and atlases is the relation between number of species and sampling
effort (Vallet et al. 2012). This relation is
investigated mainly using non parametric estimators, less sensitive to the
sampling effort (Palmer 1990; Brose et al. 2003). Such indexes give an estimate
of the species richness for a given geographic unit, based upon the considered
sample and, therefore, upon its species assemblage. Once an estimate value is
obtained, the completeness for each of the three datasets can be calculated by
means of the completeness index proposed by Soberón
et al. (2000). Such index (C) is expressed as a percentage value of the ratio
between the number of observed species (Sobs) and the number of
estimated species (Sest):
C = Sobs/Sest
The most used non parametric estimators for presence/absence data or
incidence data are Jackknife, Chao, Bootstrap, and ICE (Gotelli
& Colwell 2011; Vallet et al. 2012). While the
first of these indexes could represent a good compromise (Brose et al. 2003),
several other authors prefer to compare more than one index (Martinez-Sanz et
al. 2010; Bruno et al. 2012; Garcia-Marquez et al. 2012; Vallet
et al. 2012; Archer 2019). It is therefore noted that the Jackknife estimator
gives higher values of estimated richness and, accordingly, lower completeness
values than the Bootstrap estimator (Garcia-Marquez et al. 2012). Nevertheless,
it is particularly effective in estimating the richness of small sample size (Hortal et al. 2006). Another very used estimator is Chao2 (Ugland et al. 2003; Chao & Chiu 2016; Idohou et al. 2015; Asase &
Peterson 2016) that gives more emphasis to the presence of singletons species
(i.e., present in only one plot of the set or subset) or doubletons (i.e.,
present in only two plots). Considered that many orchid species are locally
rare and the number of rare species increases with decreasing the size of the
sampled area, I calculated the completeness index (C) choosing as value of
estimated richness (Sest) the maximum
value between Chao2 (SChao2) and Jackknife1 (Sjack1)
estimates. For each of the three study areas I calculated the total value of
completeness (C) and the completeness of each cell of the 1 km2 UTM
grid, using the plots as sampling units. Only for Roccamonfina
area the completeness has been calculated also for each cell of a 4 km2,
9 km2, 16 km2, 25 km2, and 36 km2
UTM grid intersecting the study area. Then I aggregated the data into 1 x 1 km
cells and the obtained taxon × cells matrix has been used to recalculate the
estimated species richness and the completeness of each study area. This was
intended to test the reliability of such atlases built mapping the presence of
the species in grids with cells of 1 km2 or more, to estimate the
species richness of the study areas. In order to test
the estimators robustness when even larger sample units are used, the above
mentioned aggregation method has been repeated using grids of 4 km2, 9 km2, 16 km2, 25 km2,
and 36 km2 cells, only for the
larger area of Roccamonfina volcano. In other terms,
I used increasing size cells as sampling units. Such cells size can be useful
to analyse atlases produced with bibliographic data whose precise geolocation
is not possible. The completeness of each cell, for all the grids of different
cells size, has been classified into four levels: 0–25 %, 25–50 %, 50–75 %, and
75–100 %. The cell with less than six plots have not been analysed and have
been classified as “not evaluable” (n.e.). These
limits have been set considering for all the datasets used an average number of
five plot sampled in a day. According to the method used in Bruno et al.
(2012), the cells with completeness
>65% have been considered sufficiently studied squares (SSS).
Once I knew the less explored cells, to which priority in the future
research should be given, I could assess the level of completeness of our
datasets among different habitats. So, I assigned a kind of vegetation to each
plot on the basis of the collected field information and therefore I estimated
the completeness of each vegetation type for each study area as explained
above.
The cartographic elaborations have been performed by the software Qgis3
(QGIS Development Team 2019), the rarefaction curves and the calculation of the
richness estimators have been produced by means of the software Estimates 8.20
(Colwell 2013) performing 1000 permutations. Statistical analyses have been
performed using the software PAST (Hammer et al. 2001). All the used software
is open source or free.
Results
In Table 1 the data about the three study areas are reported, including
the list of the taxa considered. The Roccamonfina
area has the highest species richness, average number of records/plot and
plot/km2. Vairanese and W-Matese show comparable values of the number of records/plot
(higher values for W-Matese) and number of plots/km2
(higher values for Vairanese). Nevertheless, the
distribution of the number of plots (Figure 2a) and observed species richness
(Figure 2b) in the 1km2 cells is extremely heterogeneous with a very
high standard deviation of the plots/cells ratio (6.9 for Roccamonfina,
6.5 for Vairanese and 5.9 for Matese
areas). Such values underline a sampling effort not uniformly distributed in
the studied areas.
The regression analysis (Figure 3) shows, for all the three areas, a
statistically significant (p <0.001) positive correlation between the number
of plots and the number of species inside the 1 km2 cells. The two
variables are statistically correlated according to the Kendall’s tau test.
The rarefaction curves (Figure 4) indicate a similar pattern for all the
three areas: limited to 121 plots, they show slight differences with a higher
species richness for the W-Matese area (32.84 average
observed species) followed by the Vairanese area (32
average observed species) and the Roccamonfina
volcano (31.32 average observed species).
The total estimated floristic richness, computed using the plots as
sampling units (Table 2) for each of the three areas, gives completeness values
between 78.2% (Vairanese) and 88.5% (Roccamonfina). Using the 1 km2 cells as sampling
units (Table 3), we get identical values for Roccamonfina
area, a slightly higher value for Vairanese area and
slightly lower for W-Matese area.
The completeness of the 1km2 cells in the three areas (Figure
2c) is distributed in a similar way in the Roccamonfina
and Vairanese areas (Table 4): the 35.6% and 33.3% of
the 1 km2 cells, respectively, have a completeness higher than 65%
and therefore are considered as Sufficiently Studied Squares (SSS). For the W-Matese area only the 25% of the 1 km2 cells are
SSS. It is relevant, for each area, the great number of cells with data not
allowing further elaborations (‘n.e.’ cells).
The estimated richness for the Roccamonfina
area, calculated using sampling units of increasing size (Figure 5) shows a
general stability of the two estimators chosen, always with higher values for
Jackknife1 estimator (51.82–53.47) compared to Chao2 estimator (48.11–49.34).
Both the estimators feature variations included within 1.65 unity, a value
lower than the standard deviations calculated by the software. The completeness
of the cells of increasing size, calculated for Roccamonfina
area (Table 5) using the plots as sampling units, gives a gradual increase of
the number of SSS, up to over 50% of the 9 km2 cells and 80% of the
36 km2 cells.
In Table 6 the observed and estimated species richness and the
completeness of the different habitats using the plots as sampling units are
reported. For the Roccamonfina area the completeness
of the habitats is high except for agricultural environments. The chestnut
orchards host the higher species richness (38 species, 82% of the whole area),
followed by the open habitats such as meadows and shrublands (33 species). In
the other study areas the completeness is relatively low for the broadleaved
woodlands of Vairanese and open habitats of the W-Matese, indicating a still not adequate sampling for such
habitats. For a better comparison of the species richness among the different
habitats, considering that more than 70% of the plots are located inside
chestnut orchards, the rarefaction curves were plotted for Roccamonfina
habitats (Figure 6), limited to 100 plots. The richness curve rises in a
steeper way in the chestnut orchards but it is overtaken by artificial habitats
around 30 plots and by open habitats around 50 plots. The richness of
broadleaved woodlands and chestnut coppices is always lower, as expected.
Discussion
The higher species richness is correlated to the sampling effort,
expressed as number of plots, as well as the ecological features of the areas
and their extension. This parameter is known, in ecology as the species/area
relationship (SAR - Preston 1962) and it could be used to compare and estimate
species richness of floristic atlases only under certain conditions that, if
disregarded impede its extrapolation (Vallet et al.
2012). The correlation analysis here performed confirms that the higher is the
number of sampling units (plot) in an area, the higher will be the observed
species richness. Comparing the richness of the three studied areas plotted by
rarefaction curves, highlights that with the same sampling effort (i.e., the
same number of plots), the richest area can host a relatively lower number of
species than the less rich area. Nevertheless, such kind of analysis requires
the same exhaustivity of the studies for each area. The overall completeness of
the study areas gives values close to 90% and consistently above 70%. Also,
very interesting is the data emerging from the estimates of the richness and
the completeness calculated using the 1 km2 cells of the UTM grid as
sampling units. Such size could be very useful to study larger areas or to
include lower precision data in the analysis and the completeness values did
not differ significantly from the resulting estimates obtained using 100 x 100
m sampling units (plots). For the Roccamonfina area,
in addition, even using increasing size cells as sampling units, the estimates
do not vary significantly. This result can be taken into account whenever we
have to choose the better grid resolution to draw atlases from non punctual data (e.g., literature data or observations
with low location accuracy). The elaborations should follow, in this case, a
reverse path: starting from a large sampling unit (e.g., a 10 x 10 km cells UTM
grid), decreasing the size of the sampling units and calculating the
completeness for the study area. Since small size cells will have more
probability to hold ‘singletons’ (unique presence data) for a bigger number of
species, the used estimators will give higher estimates of richness and,
therefore, lower values of completeness.
For the same reason linked to the presence of singletons, in our study
the number of sufficient studied squares (SSS) increases as their size become
bigger. In the case of Roccamonfina area, using a
grid of 9 km2 cells, a half of them are classified as SSS. The
distribution of the completeness for a grid of 1 km2 cells (Table
4), on the other hand, is comparable for Roccamonfina
and Vairanese, with more than 33% of the squares
classified as SSS while for W-Matese area this value
reaches only 25%. To assess whether these rates represent a good result (i.e.,
the area is exhaustively well studied), we can refer to the choice of the limit
of 65% to consider a cell as sufficiently studied. In Bruno et al. (2012) this
completeness limit has been chosen to select a useful number of squares to
perform further analysis. These authors, for all the four considered taxonomic
groups, get lower portion of squares SSS compared to the portion we get for our
studied areas. Nevertheless, the absolute number of SSS for both Vairanese and W-Matese areas
(respectively six and five squares) is too low and recall the need to continue
the study in these two areas.
The stratified analysis by habitat types underlines firstly what habitats need
more studies or are less suitable for orchids. For example, agricultural
habitats for Roccamonfina would need further sampling
since their completeness is only 55% (Table 6). It could be expected that,
adding further sampling, the completeness would increase even without an
increasing of the species richness. These habitats are in fact less suitable to
host orchids as they are affected by frequent and strong ecological changes
(e.g., soil tillage, switching to other crops, supply of nutrients). Such
considerations could be made for the broadleaved woodlands of the Vairanese area, mostly represented by Holm oaks woodlands
with very low light in the understory since orchids abundance is highly
correlated to light regime (Djordjević & Tsiftsis 2020; Hrivnák et al.
2020). On the contrary we expect that
the low completeness value for the open habitats of the W-Matese
area is due to a high theoretical richness of such habitats, not fully detected
by the sampling activity. In other words, the sampling effort for the open
habitats of the W-Matese area is still insufficient.
Also, the rarefaction curves allow ecological considerations (Figure 6). The chestnut
orchards represent an ecosystem made of a mosaic between woodlands and meadows,
so they are a suitable habitat for the most heliophilous
species as well as for the nemoral ones. This
explains why their average species richness increases steeply even with a few
plots (it is possible to observe more than 20 species in one plot).
Nevertheless, on a larger scale, the richness of chestnut orchards is higher
than the richness in open habitats only because of the higher area occupied by
the former. When the curves are limited to 50 plots, surprisingly the richest
habitats are the artificial areas. This result can be explained with the apophyte behavior of many orchids species (Adamowski 2006) and with the fact that we considered the
roadsides as artificial habitats. Such environments can host many species
characteristics of open habitats such as meadows and grasslands, and constitute
important refuge areas for native species (Auestad et
al. 2011).
Overall, the analysis of the three datasets allowed the sampling effort
to be evaluated and gave useful indications to where and how to conduct the
future researches. Moreover, some suggestions on the use of statistical tools
to compare different study areas were given. For two areas (Roccamonfina and Vairanese), there is a sufficient level of knowledge of how
the orchids richness is distributed, if we assume that a low completeness value
in two squares out of three could be due to the lack of suitable habitats
(i.e., urban areas or intensive agriculture areas) and to the difficult to
locate a sufficient number of sampling units or plots. The squares with no data
or with a lower completeness should be regarded as the highest priority areas
for the future floristic research. Sampling these areas could increase the
level of knowledge (i.e., the completeness value) and could lead to detect new
species for the squares or for the studied area. The analysis of the floristic
richness and the completeness of every habitat in a less known area would be
very useful to prioritize, in each cell of a chosen grid, where to focus the
research.
CONCLUSIONS
In conclusion, this study highlights that the quality of a floristic
research can benefit from the evaluation of the completeness. Its calculation
allows the creation of knowledge/ignorance maps for orchids at different scale
using grids at different resolutions (e.g., from cells of 1 km2 for
small islands and reserves to cells of 100 km2 for regions). A
randomized and stratified sampling design would reduce the sampling bias,
enable the use of abundance indices rather than presence/absence data and allow
the investigation on the relation between species richness and environmental
variables. It is often necessary, however, to take into account a large amount
of data lacking accuracy or uniformity as is the case of data from literature
or collected by different and sometimes occasional contributors (e.g., in
citizen science projects).
In any case it is desirable in each modern floristic study and
particularly orchids distribution study, a quantitative analysis of the work
expressing the results not only as the total number of species observed and
their distribution but focusing more on the sampling methods and on the
distribution of the knowledge. Even if a sampling design avoiding preferential
sampling would be desirable but not always possible (e.g., when using data from
online platforms or literature), the proposed methods would help the authors to
evaluate the sampling effort, identify the less studied areas or postpone the
publication of their checklists and atlases until an acceptable level of
exhaustivity, or completeness, would be reached.
Table 1.
Data of the three study areas and list of the taxa considered for the analysis.
|
Roccamonfina |
Vairanese |
W-Matese |
Sobs |
46 |
32 |
33 |
Area (km2) |
210 |
18 |
20 |
1 km2
cells |
163 |
18 |
20 |
altitude
(min-max) |
150–1005 |
125–588 |
150–811 |
Number
of Plots |
1184 |
121 |
124 |
Database-records |
3046 |
263 |
296 |
records/plot |
2.57 |
2.17 |
2.39 |
Plot/km2 |
7.26 |
6.72 |
6.2 |
Anacamptis coriophora (L.) R.M.Bateman,
Pridgeon & M.W.Chase |
x |
x |
x |
Anacamptis morio (L.) R.M.Bateman,
Pridgeon & M.W.Chase |
x |
x |
x |
Anacamptis papilionacea (L.) R.M.Bateman, Pridgeon & M.W.Chase |
x |
x |
x |
Anacamptis pyramidalis (L.) Rich. |
x |
x |
x |
Cephalanthera damasonium (Mill.) Druce |
x |
x |
x |
Cephalanthera longifolia (L.) Fritsch |
x |
|
x |
Cephalanthera rubra (L.) Rich. |
x |
|
|
Dactylorhiza maculata (L.) Soó
subsp. saccifera (Brongn.)
Diklić |
x |
x |
|
Dactylorhiza romana (Sebast.) Soó subsp. romana |
x |
x |
|
Dactylorhiza sambucina (L.) Soó |
x |
|
|
Epipactis exilis P.Delforge |
x |
|
|
Epipactis
helleborine (L.) Crantz subsp.
helleborine |
x |
x |
|
Epipactis microphylla (Ehrh.) Sw. |
x |
x |
x |
Epipactis muelleri Godfery |
x |
x |
|
Epipactis maricae (Croce, Bongiorni,
De Vivo & Fori) Presser & S.Hertel |
x |
|
|
Epipactis placentina Bongiorni & Grünanger |
x |
|
|
Gymnadenia conopsea (L.) R.Br. |
x |
|
|
Himantoglossum adriaticum H.Baumann |
x |
|
x |
Limodorum abortivum (L.) Sw. |
x |
x |
x |
Neotinea maculata (Desf.) Stearn |
x |
x |
x |
Neotinea tridentata
(Scop.) R.M.Bateman, Pridgeon & M.W.Chase |
x |
x |
x |
Neottia nidus-avis (L.) Rich. |
x |
|
|
Neottia ovata (L.) Bluff
& Fingerh. |
x |
|
|
Ophrys apifera Huds. |
x |
x |
x |
Ophrys argolica H.Fleischm. ex Vierh. subsp. crabronifera (Mauri)
Faurh. |
x |
x |
x |
Ophrys bertolonii Moretti subsp.
bertolonii |
x |
x |
x |
Ophrys bombyliflora Link |
|
|
x |
Ophrys exaltata Ten. subsp. montis-leonis
(O.Danesch & E.Danesch)
Soca |
x |
|
|
Ophrys holosericea (Burnm.f.) Greuter subsp. gracilis (Büel, O.Danesch & E.Danesch) O.Danesch & E.Danesch |
|
x |
|
Ophrys holosericea (Burnm.f.) Greuter subsp. holosericea |
x |
x |
x |
Ophrys incubacea Bianca |
x |
|
|
Ophrys insectifera L. |
|
x |
x |
Ophrys lutea Cav. |
x |
x |
x |
Ophrys promontorii O.Danesch & E.Danesch |
x |
|
x |
Ophrys sphegodes Mill. subsp. sphegodes |
x |
x |
x |
Ophrys sphegodes Mill. subsp. minipassionis
(Romolini & Soca)
Biagioli & Grünanger |
|
|
x |
Ophrys tenthredinifera Willd. subsp.
neglecta (Parl.) E.G.Camus |
x |
|
|
Orchis anthropophora (L.)
All. |
x |
x |
x |
Orchis italica Poir. |
x |
x |
x |
Orchis mascula (L.) subsp. mascula |
x |
|
x |
Orchis pauciflora Ten. |
|
x |
x |
Orchis provincialis Balb. ex Lam. & DC. |
x |
x |
x |
Orchis purpurea Huds. |
x |
x |
x |
Orchis simia Lam. |
x |
|
x |
Platanthera bifolia (L.) Rich. |
x |
x |
|
Platanthera chlorantha (Custer) Rchb. |
x |
x |
x |
Serapias cordigera L. |
x |
x |
|
Serapias lingua L. |
x |
|
x |
Serapias parviflora Parl. |
x |
x |
x |
Serapias vomeracea (Burm.f.) Briq. subsp. longipetala (Ten.)
H.Baumann & Künkele |
x |
x |
x |
Spiranthes
spiralis (L.) Chevall. |
x |
x |
x |
Table 2.
Total completeness values for the three study areas using 100 x 100 m plots as
sampling units.
|
Roccamonfina |
Vairanese |
W-Matese |
n. Plots
(100 × 100 m) |
1184 |
121 |
124 |
Sobs |
46 |
32 |
33 |
SChao2 |
49 |
35.72 |
37.9 |
SJack1 |
51.99 |
40.93 |
39.94 |
Completeness
% |
88.5 |
78.2 |
82.6 |
Table 3.
Total completeness values for the three study areas using 1 km2
cells as sampling units.
|
Roccamonfina |
Vairanese |
W-Matese |
No. of 1
km2 cells |
163 |
18 |
20 |
Sobs |
46 |
32 |
33 |
SChao2 |
48.98 |
40.5 |
36.33 |
SJack1 |
51.96 |
40.5 |
40.3 |
Completeness
% |
88.5 |
79.0 |
81.9 |
Table 4.
Levels of completeness values of the 1 km2 cells, for the three
study areas.
|
Roccamonfina |
Vairanese |
W-Matese |
|||
Completeness
level % |
n.
cells |
% |
n.
cells |
% |
n.
cells |
% |
n.e. |
84 |
51.5 |
7 |
38.9 |
9 |
45.0 |
0–25 |
3 |
1.8 |
2 |
11.1 |
2 |
10.0 |
25–50 |
5 |
3.1 |
1 |
5.6 |
1 |
5.0 |
50–75 |
35 |
21.5 |
4 |
22.2 |
5 |
25.0 |
75–100 |
36 |
22.1 |
4 |
22.2 |
3 |
15.0 |
Total |
163 |
|
18 |
|
20 |
|
SSS |
58 |
35.6 |
6 |
33.3 |
5 |
25.0 |
Table 5.
Levels of completeness values of the cells of different size, for the Roccamonfina area (n.e. = not
evaluated).
|
1 km2 |
4 km2 |
9 km2 |
16 km2 |
25 km2 |
36 km2 |
||||||
C |
n. cells |
% |
n. cells |
% |
n. cells |
% |
n. cells |
% |
n. cells |
% |
n. cells |
% |
n.e. |
84 |
51.5 |
23 |
37.7 |
10 |
16.4 |
5 |
22.7 |
3 |
20 |
1 |
9.1 |
0–25 |
3 |
1.8 |
1 |
1.6 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
25–50 |
5 |
3.1 |
4 |
6.6 |
5 |
8.2 |
1 |
4.5 |
1 |
6.7 |
0 |
0 |
50–75 |
35 |
21.5 |
14 |
23 |
6 |
9.8 |
7 |
31.8 |
4 |
26.7 |
2 |
18.2 |
75–100 |
36 |
22.1 |
19 |
31.1 |
12 |
19.7 |
9 |
40.9 |
7 |
46.6 |
8 |
72.7 |
tot |
163 |
|
61 |
|
33 |
|
22 |
|
15 |
|
11 |
|
SSS |
58 |
35.6 |
28 |
45.9 |
17 |
51.5 |
11 |
50 |
9 |
60 |
9 |
81.8 |
Table 6.
Completeness values of the main habitats in the three areas.
Roccamonfina |
|||||
Habitats |
Sobs |
Plots |
SChao2 |
SJack1 |
C % |
Artificial
(incl. Road verges) |
25 |
50 |
28.9 |
33.8 |
73.9 |
Agriculture |
11 |
18 |
20.0 |
16.7 |
55.0 |
Open
habitats |
33 |
158 |
36.5 |
40.9 |
80.6 |
Broadleaved
woodlands (excl. Chestnut woods) |
25 |
82 |
27.1 |
30.9 |
80.9 |
Chestnut
coppices |
18 |
62 |
19.0 |
21.0 |
85.9 |
Chestnut
orchards |
38 |
839 |
44.0 |
44.0 |
86.4 |
Vairanese |
|||||
Habitats |
Sobs |
Plots |
SChao2 |
SJack1 |
C % |
Open
habitats |
26 |
89 |
26.5 |
29.0 |
89.8 |
Broadleaved
woodlands |
24 |
33 |
42.0 |
35.6 |
57.1 |
Evergreen
woodlands |
6 |
8 |
6.7 |
8.6 |
69.6 |
W-Matese |
|||||
Habitats |
Sobs |
Plots |
SChao2 |
SJack1 |
C % |
Open
habitats |
28 |
60 |
100.0 |
39.8 |
28.0 |
Broadleaved
woodlands |
27 |
57 |
28.6 |
32.0 |
84.4 |
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