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Abstract

A high proportion of plant species is predicted to be threatened with extinction in the near future. However, the threat status of only a small number has been evaluated compared with key animal groups, rendering the magnitude and nature of the risks plants face unclear. Here we report the results of a global species assessment for the largest plant taxon evaluated to date under the International Union for Conservation of Nature (IUCN) Red List Categories and Criteria, the iconic Cactaceae (cacti). We show that cacti are among the most threatened taxonomic groups assessed to date, with 31% of the 1,478 evaluated species threatened, demonstrating the high anthropogenic pressures on biodiversity in arid lands. The distribution of threatened species and the predominant threatening processes and drivers are different to those described for other taxa. The most significant threat processes comprise land conversion to agriculture and aquaculture, collection as biological resources, and residential and commercial development. The dominant drivers of extinction risk are the unscrupulous collection of live plants and seeds for horticultural trade and private ornamental collections, smallholder livestock ranching and smallholder annual agriculture. Our findings demonstrate that global species assessments are readily achievable for major groups of plants with relatively moderate resources, and highlight different conservation priorities and actions to those derived from species assessments of key animal groups.
High proportion of cactus species threatened
with extinction
Bárbara Goettsch et al.*
A high proportion of plant species is predicted to be threatened with extinction in the near future. However, the threat
status of only a small number has been evaluated compared with key animal groups, rendering the magnitude and nature
of the risks plants face unclear. Here we report the results of a global species assessment for the largest plant taxon
evaluated to date under the International Union for Conservation of Nature (IUCN) Red List Categories and Criteria, the
iconic Cactaceae (cacti). We show that cacti are among the most threatened taxonomic groups assessed to date, with 31%
of the 1,478 evaluated species threatened, demonstrating the high anthropogenic pressures on biodiversity in arid lands.
The distribution of threatened species and the predominant threatening processes and drivers are different to those
described for other taxa. The most signicant threat processes comprise land conversion to agriculture and aquaculture,
collection as biological resources, and residential and commercial development. The dominant drivers of extinction risk are
the unscrupulous collection of live plants and seeds for horticultural trade and private ornamental collections, smallholder
livestock ranching and smallholder annual agriculture. Our ndings demonstrate that global species assessments are
readily achievable for major groups of plants with relatively moderate resources, and highlight different conservation
priorities and actions to those derived from species assessments of key animal groups.
Plants are of fundamental importance to much of the rest of bio-
diversity and to many ecosystem functions, processes and ser-
vices. However, the global status of plant species, that is their
likelihood of extinction in the near future, remains poorly under-
stood. Only 19,374 (6%) of an estimated 300,000 species1have
been evaluated against the current IUCN Red List Criteria2.
Moreover, global species assessments, in which the extinction risk
of every extant species in a taxonomic group is systematically
assessed, have been conducted only for very few plant groups
(such as cycads, conifers, mangroves, sea grasses35) of which
most are not especially diverse.
This situation is troublesome because there is evidence
suggesting that the conservation status of plant species is of particu-
lar concern. Despite the small proportion of plants whose threat
status has been evaluated, they nonetheless constitute a high pro-
portion (47%) of all threatened species (across all kingdoms) cur-
rently on the IUCN Red List5. In addition, plant species are
known to have geographic range sizes, a key correlate of extinction
risk, that are on average smaller than those of many other groups;
the smallest ranges are typically also much smaller than their
equivalents among vertebrate groups6. Estimates of likely levels
of recent and future plant extinction also indicate that these may
be high7,8.
Responding to this concern, determining the threat status of all
known plant species, as far as is possible, has been identied as a
key target for the Global Strategy for Plant Conservation 2011
2020 (ref. 9). This follows the global failure to meet the previous
incarnation of this target as of 2010 (ref. 10). It is difcult to deter-
mine why, in contrast to vertebrates5,11,12, progress has been so slow,
and comprehensive assessments of plant groups are so scarce. Likely
reasons include the assumption that there is insufcient information
available to assess most plant species against the IUCN Red List
Criteria, including data on speciesgeographic distributions
(although much valuable distributional data undoubtedly reside,
unsynthesized, in herbaria and botanical collections). In addition,
plants lack the popular appeal of some animal groups, making it dif-
cult to attract the funding to support global species assessments.
And the costs of such assessments are thought to be restrictively
high1318.
Here we challenge these assumptions, presenting the results of the
largest comprehensive assessment to date of an entire plant taxon, the
cacti, against the IUCN Red List Categories and Criteria (1,480 extant
species of which 1,478 were evaluated, with two species for which no
information could be obtained). We focus on the levels of threat to
species, how species at different levels of threat are distributed, the
nature of the threats and the practicality of such global species assess-
ments for plants. The cacti are a culturallysignicant group, perceived
as amongst the more charismatic of plant taxa. This has led to a long
history of human use, including for private and public ornamental
plant collections, leading to major conservation concerns.
Surprisingly, only 11% of cactus species had been evaluated for the
Red List before 2013. Cacti are distributed predominantly in, and
are somewhat emblematic of, New World arid lands (only one
species naturally occurs in Africa and Asia; Supplementary
Table 1). Despite huge anthropogenic pressures, these regions have
not attracted the conservation attention associated with other
biomes, particularly tropical forests19,20.
Levels of threat
Using the IUCN Red List Categories and Criteria, we found that
cacti are the fth most threatened5of any major taxonomic group
to be completely assessed to date, with 31% of species threatened.
The only groups to contain a higher proportion of threatened
species are cycads (63% threatened species5), amphibians
(41%5,11), corals (33%5,21) and conifers (34%5). Therefore, three of
the ve most threatened groups assessed to date are plants. By com-
parison, 25% of mammal species5,12 and 13% of bird species are
threatened5. Among the cacti, 99 (6.7%) species are classied as
Critically Endangered, 177 (12%) as Endangered and 140 (9.4%)
as Vulnerable (Supplementary Table 2).
*A full list of authors and their afliations appears at the end of the paper.
ARTICLES
PUBLISHED: 5 OCTOBER 2015 | ARTICLE NUMBER: 15142 | DOI: 10.1038/NPLANTS.2015.142
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Hotspots of threat
The hotspots of threatened cactus species overlap little, if at all,
with those that have been highlighted for other taxonomic
groups and that consequently have driven much thinking about
the role of such areas in conservation planning (Fig. 1).
Whereas hotspots of threatened cacti are inevitably found in
arid regions, those of threatened species of amphibians, birds
and mammals tend to be found in more mesic habitats. The
peak of threatened cactus species richness is found in a highly
restricted area in southern Rio Grande do Sul, Brazil, and north-
ern Artigas, Uruguay (area 500 km
2
; Fig. 1a). This region also
shows a peak in the proportion of species threatened with extinc-
tion (Fig. 2a). Other hotspots of threatened cacti are found in the
states of Querétaro and San Luis Potosí, and in Oaxaca and
Puebla in the Tehuacán-Cuicatlán region, Mexico; in Brazil in
eastern Bahia and northern Minas Gerais; in Chile in the southern
portion of Antofagasta; and in eastern Uruguay (Fig. 1a). The nar-
rowness of the peaks of threatened species richness of cacti reects
their particularly small geographic range sizes (rst quartile
<1,332 km
2
, median range size of threatened species is
1,529 km
2
). Other areas with a low overall richness but a high
proportion of threatened species occur in Guatemala, Colombia
and several parts of Peru and Chile (Fig. 2a). The main centres
of cactus diversity are found in the Chihuahuan Desert and in
the Tehuacán-Cuicatlán region, in northern and central Mexico
respectively, and in southern Bolivia and eastern Brazil (Fig. 2a;
ref. 22). Some of these species-rich areas coincide with hotspots
of threatened cactus species (Fig. 1a).
Threats
Cacti experience a diverse range of threats, the predominant pro-
cesses (that is the direct human activities responsible for the degra-
dation, destruction and/or impairment of biodiversity23) being land
conversion to agriculture and aquaculture, collection as biological
resources, and residential and commercial development (Figs 3a
and 4a). Agriculture is the most widespread threat to cacti, affecting
species in large parts of northern Mexico, Mesoamerica and the
southern portion of South America (Fig. 3a). Cacti in coastal
areas, such as the Baja California peninsula in Mexico and the
Caribbean, are mainly affected by residential and commercial
development. The latter threat, in conjunction with agriculture,
affects cacti along the Pacic coast of Mexico and the central
coast of Brazil. Collecting cacti for biological resources (for
instance for ornamental collections and wood) is the main threat
process affecting species distributed along the Peruvian and
Chilean coasts. Unsurprisingly, areas where all three threat pro-
cesses act together are often regions harbouring the highest concen-
trations of threatened species, such as central Mexico and eastern
Brazil (Fig. 3a).
The most important proximate drivers of extinction risk, that is
the ultimate factors contributing to or enabling the threat process23
among threatened cacti, are unscrupulous collection of live plants
and seeds for the horticultural trade and for private ornamental col-
lections (affecting 47% of threatened cacti), smallholder livestock
ranching (31%) and smallholder annual agriculture (24%; Fig. 4b).
In eastern and southern Brazil, the two main drivers of land use
change are smallholder ranching and smallholder agriculture,
affecting 61 and 46 species, respectively (Fig. 3b,e). However, an
additional driver of land use change in southern Brazil is agro-
industrial plantations of Eucalyptus (Fig. 3c); land conversion for
plantations affects at least 27 species, including the Endangered
Parodia muricata, but also the leaf litter from these trees shades
cacti, preventing them from being pollinated and from owering,
and often kills adult specimens. In eastern Brazil, the situation is
exacerbated by a relatively high number of species (15 in Bahia
and 19 in Minas Gerais) that are affected by quarrying, the fth
most frequent threat driver for threatened cacti (Fig. 4b). Edaphic
specicity is common among these plants24 and a large number
of Brazilian species, such as Arthrocereus glaziovii and
Coleocephalocereus purpureus, only grow on iron-rich canga or on
inselbergs, both of which are sought after by the mining industry.
An extreme case is that of Arrojadoa marylaniae, which may
become extinct in the near future, for the single white quartz rock
on which it is exclusively found is threatened by mining. In
north-central Mexico the two main drivers of land use change are
the same as in Brazil, with nomadic grazing as an additional
driver of land use change in this region (Fig. 3b,d,e). In the north-
western part of Mexico, species such as Mammillaria bocensis and
Corynopuntia reexispina are unexpectedly becoming threatened
by aquaculture, as shrimp farming expands into the desert.
Cactaceae are a key component of the arid oras of the New
World. They are probably more susceptible to collection activities
than other groups of plants that are characteristic of these environ-
ments. However, until similar assessments are completed for such
other groups it is hard to speculate on how the threats will differ,
especially for plants with more ephemeral life cycles.
Human use
Unlike most other groups that have been completely globally
assessed to date, more than a half of all cactus species (57%) are
used by people. The most common use is for ornamental horticul-
ture (674 species), which in most cases is related to gathering plants
and seeds for specialized collections. People also use cacti as food for
human consumption (154 species) and medicine (both human and
veterinary; 64 species; Fig. 4c). Among the threatened cacti species,
ab
cd
14 31
11
11
27 36
Figure 1 | Geographic distribution of threatened species. ad, Number of
threatened species (IUCN Red List Categories Vulnerable, Endangered and
Critically Endangered) of cacti (a), amphibians (b), birds (c) and mammals
(d) (see Methods).
ARTICLES NATURE PLANTS DOI: 10.1038/NPLANTS.2015.142
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ab
81
100
1
1
Figure 2 | Patterns of biodiversity of Cactaceae. a, Proportion of species that are threatened (Vulnerable, Endangered and Critically Endangered). b,Total
species richness.
Species absent or values of
all three threats are low
Biological
resource use
Agriculture
and
aquaculture
Residential
and
commercial
development
abc
de
9
11
1
1
412
13
Figure 3 | Threatening p rocesses and drivers impacting c acti. a, Geographical distribution of the three most common threat processes. Green, agriculture/
aquaculture; red, overexploitation; and blue, residential/commercial development. These colours change as the threats combine, turning white when all three
threats are present in an area. The brighter the colour, the higher the number of species affected by that particular threat. Black corresponds to thoseareas
where all three threat values are low. be, Geographic distribution of threat drivers: smallholder ranching (b), wood agroindustry plantations (c), nomadic
grazing (d) and annual smallholder farming (non-timber crops) (e).
NATURE PLANTS DOI: 10.1038/NPLANTS.2015.142 ARTICLES
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Horticulture
50
40
30
20
10
0
% of threatened species % of threatened species % of threatened species
40
30
20
10
0
40
30
20
10
0
40
20
0
% of species
Food for
humans
Medicine
(human and
veterinary)
Horticulture Food for
humans
Medicine
(human and
veterinary)
Food for
animals
Food for
animals
Handicrafts
Construction
materials
a
b
c
d
Gathering
plants
Livestock
smallholder
Smallholder
farming
Housing
and
urban areas
Mining
and
quarrying
Increase
in fire
Annuals
agroindustry
farming
Woo d
agroindustry
plantations
Tourism
and
recreation
areas
Invasive
species
PollutionClimate
change
Human
intrusions
and
disturbance
Transportation
and
service
corridors
Invasive
species
Natural
system
modifications
Energy
production
and
mining
Residential
and
commercial
development
Biological
resource
use
Agriculture
and
aquaculture
Figure 4 | Cactus species affected by different threat processes and drivers, and used for different purposes. a, Percentage of threatened cactus species
threatened by different processes. b, Percentage of threatened cactus species experiencing different proximate threat drivers. c, Percentage of cactus species
used for different purposes. d, Percentage of threatened cactus species used for different purposes. Only the main threats and uses are shown; for complete
lists of threat processes, threat drivers and uses see Supplementary Tables 36.
ARTICLES NATURE PLANTS DOI: 10.1038/NPLANTS.2015.142
NATURE PLANTS |www.nature.com/natureplants4
64% are utilized by humans in some form and 57% (236 species) are
used in horticulture (Fig. 4d). Ever since Europeans rst discovered
cacti, they have been regarded as precious collectable objects sought
by collectors for their unique appearance, unpredictably beautiful
owers and their rarity in terms of the narrowness of their geo-
graphic ranges. Large cacti are sought after as major exhibition
pieces, but smaller ones are more readily discreetly collected. A
general linear model identied signicant differences in height
between threat categories, between cacti that are utilized and those
which are not, and with mean elevation, although the explanatory
power of the nal model was low (R
2
= 0.106); whether the
species was in a protected area or not was also retained in the
model but was not signicant (full details Supplementary
Information Tables 7 and 8). Height was different between threat
categories (F
[4,693]
= 8.29, P< 0.0001) with Least Concern and
Near Threatened species being signicantly taller than Critically
Endangered ones (difference in mean Least Concern (mean= 2.51 m,
s.e. = 0.154 m, n= 475) and Critically Endangered (mean =
1.27 m, s.e. = 0.41 m, n= 41) 1.241 m; Near Threatened (mean =
4.59 m, s.e. = 2.4 m, n= 41) and Critically Endangered difference
in mean 3.32 m). Cacti which are utilized were signicantly
smaller than those which are not (F
[2,693]
= 17.94, P< 0.0001), and
there was a signicant inverse relationship between cactus height
and mean elevation (F
[1,693]
= 15.07, P< 0.001).
A cumulative link model exploring factors affecting the IUCN
threat category of each species also had low explanatory power
(pseudo R
2
= 0.104). It did, however, identify signicant differences
in threat category between species found in protected areas
compared with those which were unprotected (likelihood ratio stat-
istic = 19.37, P< 0.001 see Supplementary Table 9 for full model
results). The proportion of Least Concern species was much
greater in protected areas, and unprotected areas had greater pro-
portions of Vulnerable, Endangered and Critically Endangered
species. The model also highlighted height (z= 1.98, P= 0.047)
and upper elevation (z= 1.9, P= 0.057) as having marginally signi-
cant effects on threat category.
Trade in cactus species takes place at both national and inter-
national levels, and it is often illegal25. We found that 86% of threa-
tened cacti used in horticulture are extracted from wild populations.
Illegal trade has been reduced to a certain extent by the inclusion,
since 1975, of the whole family (with a few exemptions) in the
Convention on International Trade in Endangered Species of
Wild Fauna and Flora (CITES) and by the availability of plants
grown from seed in international markets. However, the threat of
collection prevails, especially in those countries where the
implementation of CITES has only recently been enforced, such
as in Peru, where the proportion of species in peril from trade is
high. Illegal trade is a latent threat for all newly described cactus
species. For example, the precise locality of Mammillaria luethyi is
known to only a small number of experts to protect the wild popu-
lation from unsustainable collecting.
Knowledge and practicality
In contrast to many animal groups assessed to date, levels of Data
Decient (DD) listings among cacti are relatively low. Only 129
species (8.7%) of cacti were assessed as DD (Supplementary
Table 1), meaning that there was inadequate information to assess
their extinction risk based on distribution and/or population data.
This is markedly lower than for vertebrate groups: 15% for
mammals, 25% for amphibians and 46% for sharks and rays5,26.
Low levels of DD cactus assessments mirror those of other less spe-
ciose plant groups that have been fully assessed to date (for example
conifers, 1%; cycads, 1%; mangroves, 4%; sea grasses, 12%5
,26
). This
is likely to be a consequence of the relatively greater ease of gathering
data on the occurrence of plants than for many mobile cryptic
animal species. It suggests that in practice assessing the status of
at least some major plant groups is not substantially more challen-
ging in terms of data availability than for animal groups that have
attracted considerably more conservation attention.
For cacti, the global species assessment process took about 6 h
per species and cost US$167 per taxon, including paid staff time,
volunteered expert and staff time and workshop costs. Thus in a
year, one full-time person looking at all aspects of an assessment
(contacting experts, organizing workshops, fundraising) could
evaluate around 363 species. Combined with the above results this
clearly demonstrates that, with relatively moderate resources,
global species assessments can be undertaken for major plant
taxa; overall, the assessment for cacti cost less than many standard
research grants issued through major funding bodies. Moreover,
as evidenced here, such exercises can reveal patterns in the distri-
bution and prevalence of threats that are fundamentally different
from those for other groups that have been globally assessed.
Indeed, these exercises are integral to planning conservation activi-
ties to protect more effectively all threatened biodiversity at a global
scale. To assess all described plant species by 2020, based on the
resources used for the global cactus assessment, it would take at
least 157 people working fulltime on assessments for 5 years at a
cost of approximately US$47 million. The goal of evaluating a sub-
stantial proportion of plant species and thereby contributing to the
achievement of the Global Strategy for Plant Conservation is thus
both undoubtedly achievable and vital.
Methods
Existing data were gathered from the literature for each of 1,478 cactus species on
their distribution, population trend, habitat preference and ecology, conservation
actions, use and trade (see Materials and Methods for details). This included over
38,000 occurrence point records, which were used to generate preliminary range
maps. This information was evaluated at a series of nine formal expert workshops,
and then used by the participants to evaluate the extinction risk of each species using
the IUCN Red List Categories and Criteria2.
Received 24 October 2014; accepted 29 August 2015;
published online 5 October 2015
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Acknowledgements
In memory of Betty Fitz-Maurice and Eduardo Méndez. We are grateful to the Universityof
Shefeld and the University of Exeter for housing the Global Cactus Assessment (GCA); for
the institutional support of IUCN, in particular staff of the Global Species Programme, the
IUCN Species Survival Commission and the IUCN SSC Cactus and Succulent Specialist
Group and the ofce of the Chair of IUCN SSC which made available valuable resources, via
the Environment Agency of Abu Dhabi, at a critical juncture in the project; to the donors
and hosts who made the eight GCA workshops possible as well as the individuals (in
parentheses) who helped with the organization and logisticsMexicos Comisión Nacional
de Areas Naturales Protegidas, Comisión Nacional para Conocimiento y Uso de la
Biodiversidad (S. Cariaga and A. López) and Instituto Nacional de Ecología, Conservation
International, the North of England Zoological Society, Jardín Botánico Regional de
Cadereyta (E. Sánchez and M. Magdalena Hernández Martínez), Desert Botanical Garden
(C. Butterworth), the Cactus and Succulent Society of America, Jardin Exotique de Monaco
(J.-M. Solichon), the Prince Albert II of Monaco Foundation, Conservation International-
Brazil, Instituto Chico Mendes, Instituto Argentino de Investigaciones de Zonas Áridas
(R. Kiesling and M. Superina), The Mohamed bin Zayed Species Conservation Fund,
Instituto de Ecología y Biodiversidad project P05-002 ICM, Universidad de Chile
(P. Guerrero), Fairchild Tropical Botanic Garden (J. Maschinski), National Fish and
Wildlife Foundation, Laboratorio de Cactología at the Insituto de Biología UNAM
(H. Hernández and C. Gómez-Hinostrosa) and Keidanren Nature Conservation Fund; and
to G. Charles, P. Hoxey, J. A. Hawkins, C. Yesson and Sukkulenten-Sammlung Zürich who
provided point locality data. B.G. was partially funded by Consejo Nacional de Ciencia y
Tecnología grant 0000000000118202. We are indebted to the hard work put in by
volunteers P. Durán, E. Hounslow, R. Lee, C. Malone, C. F. Rose, K. Watt and S. Willhoit; to
L. Bacigalupe and J. Bennie for assistance with analyses; and to M.L. Ávila-Jiménez,
J. Bennie, M.G. Gaston, S. Gaston and ve anonymous reviewers for comments on
the manuscript.
Author contributions
B.G. and K.J.G. jointly created, developed and led the project. C.H.T., A.F., H.M.H., J.S.,
M.S., N.P.T., M.T., A.M.A, S.A., H.J.A.N., M.A.B., R.T.B., D.B., P.B., C.A.B., A.B., F.C.,
M.C.B., R.C.D., M.D.V.P., P.H.D., W.A.D.B., R.D., L.F.Y., R.S.F., B.F.M., W.A.F.M., G.G.,
C.G.H., L.R.G.T., M.P.G., P.C.G., B.H., K.D.H., J.G.H.O., M.H., M.I.I., R.K., J.L., J.L.L.D.,
C.R.L.S., M.L., M.C.M., L.C.M., J.G.M.A., C.M., J.M., E.M., R.A.M., J.M.N., V.N., L.J.O.,
P.O.B., A.B.P.F., D.J.P., J.M.P., R.P., J.R.G., P.S.P., E.S.M., M.S., J.M.S.M.C., S.N.S., J.L.T.M.,
T.T., M.T., M.T., T.V., T.R.V., M.E.V., H.E.W., S.A.W., D.Z., J.A.Z.H. contributed to the
species assessment process. G.C.P., J.P.D., R.I. and C.P. conducted the analyses. B.G. and
K.J.G. drafted the manuscript and this was commented on by all of the authors.
Additional information
Supplementary information is available online.
Reprints and permissions information is
available online at www.nature.com/reprints. Correspondence and requestsfor materials should
be addressed to B.B. and K.J.G.
Competing interests
The authors declare no competing nancial interests.
Bárbara Goettsch1*, Craig Hilton-Taylor1, Gabriela Cruz-Piñón2,JamesP.Duffy
3,AnneFrances
4, Héctor M. Hernández5,
Richard Inger3, Caroline Pollock1,JanSchipper
6,7, Mariella Superina8, Nigel P. Taylor9, Marcelo Tognelli10, Agustín M. Abba11,
Salvador Arias12, Hilda J. Arreola-Nava13,MarcA.Baker
14, Rolando T. Bárcenas15,DunielBarrios
16,PierreBraun
17,Charles
A. Butterworth14,AlbertoBúrquez
18,FátimaCaceres
19, Miguel Chazaro-Basañez20, Rafael Corral-Díaz21,MariodelValle
Perea22, Pablo H. Demaio23, Williams A. Duarte de Barros24,RafaelDurán
25, Luis Faúndez Yancas26,27, Richard S. Felger28,
Betty Fitz-Maurice29, Walter A. Fitz-Maurice29, George Gann30, Carlos Gómez-Hinostrosa5, Luis R. Gonzales-Torres31,
M. Patrick Grifth32, Pablo C. Guerrero33,34,BarryHammel
35,KennethD.Heil
36, José Guadalupe Hernández-Oria37,
Michael Hoffmann38,39, Mario Ishiki Ishihara40, Roberto Kiesling41, João Larocca42, José Luis León-de la Luz43,
Christian R. Loaiza S.44, Martin Lowry45,MarlonC.Machado
46, Lucas C. Majure47,48, José Guadalupe Martínez Ávalos49,
Carlos Martorell50, Joyce Maschinski51, Eduardo Méndez52, Russell A. Mittermeier53, Jafet M. Nassar54,
Vivian Negrón-Ortiz55,56, Luis J. Oakley57, Pablo Ortega-Baes58,AnaBeatrizPinFerreira
59, Donald J. Pinkava48,
J. Mark Porter60, Raul Puente-Martinez48, José Roque Gamarra61, Patricio Saldivia Pérez27, Emiliano Sánchez Martínez62,
Martin Smith63, J. Manuel Sotomayor M. del C.64, Simon N. Stuart38,39,53,65,66, José Luis Tapia Muñoz25, Teresa Terrazas5,
Martin Terry67, Marcelo Trevisson68, Teresa Valverde50, Thomas R. Van Devender69, Mario Esteban Véliz-Pérez70,
Helmut E. Walter71, Sarah A. Wyatt72, Daniela Zappi73, J. Alejandro Zavala-Hurtado74 and Kevin J. Gaston3*
1International Union for Conservation of Nature, Global Species Programme, Sheraton House, Castle Park, Cambridge CB3 0AX, UK. 2Departamento
Académico de Biología Marina Carretera al Sur Km 5.5, Universidad Autónoma de Baja California Sur, Col. El Mezquitito, La Paz, BCS C.P. 23080, Mexico.
3Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE, UK. 4NatureServe, 4600 N. Fairfax Dr., 7th Floor, Arlington,
Virginia 22203, USA. 5Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Deleg. Coyoacán,
México, D.F. C.P. 04510, Mexico. 6School of Life Sciences, Arizona State University, Tempe, Arizona 85287, USA. 7Conservation & Science Department,
Phoenix Zoo, 455 N. Galvin Parkway, Phoenix, Arizona 85008, USA. 8Laboratorio de Endocrinología de la Fauna Silvestre, IMBECU, CCT CONICET
Mendoza, Avda. Dr. Adrián Ruiz Leal, S/N°, Parque General San Martín, Mendoza 5500, Argentina. 9Singapore Botanic Gardens and National Parks Board,
1 Cluny Road, Singapore 259569, Singapore. 10International Union for Conservation of Nature-Conservation International, Biodiversity Assessment Unit,
Betty & Gordon Moore Center for Science & Oceans, Conservation International, 2011 Crystal Drive, Suite 500, Arlington, Virginia 22202, USA. 11División
Zoología Vertebrados, Facultad de Ciencias Naturales y Museo, UNLP, CONICET, Paseo del Bosque s/n, La Plata 1900, Argentina. 12Jardín Botánico,
Instituto de Biología, Universidad Nacional Autónoma de México, México, D.F. C.P. 04510, Mexico. 13Instituto de Botánica del Departamento de Botánica y
Zoología, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, km. 15.5 carr. a Nogales, Zapopan, Jalisco C.P. 45110,
Mexico. 14College of Liberal Arts and Sciences, School of Life Sciences, Arizona State University, PO Box 874501, Tempe, Arizona 85287-4501, USA.
15Laboratorio de Genética Molecular y Ecología Evolutiva, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Campus Aeropuerto,
Carretera a Chichimequillas km. 2.5, Querétaro, Querétaro C.P. 76140, Mexico. 16Jardín Botánico Nacional, Universidad de La Habana, Carretera El Rocío
Km 3 1/2 Calabazar, Boyeros, La Habana, Cuba. 17Im Fusstal 37, Kerpen D 50171, Germany. 18Unidad Hermosillo, Instituto de Ecología, Universidad Nacional
Autónoma de México, Apartado Postal 1354, Hermosillo, Sonora C.P. 83000, México. 19Herbarium arequipense HUSA, Departamento de Biología, Facultad
ARTICLES NATURE PLANTS DOI: 10.1038/NPLANTS.2015.142
NATURE PLANTS |www.nature.com/natureplants6
de Ciencias Biológicas, Universidad Nacional de San Agustín, Av. Daniel Alcides Carrión s/n, Arequipa, Peru. 20Facultad de Biología, Universidad
Veracruzana, Zona Universitaria, Xalapa, Veracruz C.P. 91000, Mexico. 21Pulsar Group, LLC, Environmental Consulting and Services, 565 Bluff Canyon
Circle, El Paso, TX 79912, USA. 22Facultad de Ciencias Exactas y Naturales, UNCA, Avenida General Belgrano 300, San Fernando del Valle de Catamarca,
Argentina. 23Temperate South American Plants, Specialist Group, IUCN, Colanchanga S/N, Río Ceballos, Córdoba 5111, Argentina. 24Herbario MVM, Museo
Nacional de Historia Natural, 25 de Mayo 582, Casilla de Correo 399, Montevideo C.P. 11.000, Uruguay. 25Centro de Investigación Cientíca de Yucatán,
Calle 43 # 130 Col. Chuburná, Mérida, Yucatán C.P. 97200, México. 26 Facultad de Ciencias Agronómicas, Universidad de Chile, Santiago, Chile. 27BIOTA,
Gestión y Consultorías Ambientales Ltda., Av. Miguel Claro 1224, Providencia, Santiago, Chile. 28Herbarium, University of Arizona, Tucson, Arizona 85721,
USA. 29Hermanos Infante 225, San Luis Potosí C.P. 78250, SLP, Mexico. 30The Institute for Regional Conservation, Delray Beach, Florida, USA. 31Cuban
Botanical Society, Hernan Behn No. 171, La Habana C.P. 10900, Cuba. 32Montgomery Botanical Center, 11901 Old Cutler Road, Miami, Florida, USA.
33Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográcas, Universidad de Concepción, Casilla 160C, Concepción, Chile.
34Departamento de Ciencias Ecológicas, Instituto de Ecología y Biodiversidad, Universidad de Chile, Casilla 653, Santiago 780-0024, Chile. 35Missouri
Botanical Garden, P.O. Box 299, St. Louis, Missouri 23166-0299, USA. 36San Juan College, Farmington, New Mexico 87402, USA. 37Laboratorio de
Ecosiología Tropical, Instituto de Ecología, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, México, D.F. C.P. 04510,
Mexico. 38International Union for Conservation of Nature, Gland CH-1196, Switzerland. 39United Nations Environment Programme, World Conservation
Monitoring Centre, Cambridge CB3 0DL, UK. 40El Colegio de La Frontera Sur (ECOSUR), Carr. Panamericana y Periférico Sur s/n, Barrio de María
Auxiliadora, San Cristóbal de Las Casas, Chiapas C.P. 29290, Mexico. 41IADIZA-CONICET, Casilla de Correo 507, Mendoza 5500, Argentina. 42Fundação
Gaia-Estrada Capão da Fonte, s/n°, Caixa Postal: 353, Cep: 96690-000, Pantano, Grande/RS, Brazil. 43Herbarium HCIB, Centro de Investigaciones
Biológicas del Noroeste, SC, Apdo. postal 128, La Paz, Baja California Sur C.P. 23000, Mexico. 44Casa de la Cultura Ecuatoriana Benjamín Carrión,Núcleo
de Loja/Sección de Ciencias Naturales y Ecología, Colón 13 - 12 y Bernardo Valdivieso, Loja, Ecuador. 45International Organization for Succulent Plant Study,
83, Seaton Road, Hessle, Hull, UK. 46Herbario HUEFS, Universidade Estadual de Feira de Santana, Feira de Santana, Bahia CEP 44036-900, Brazil. 47Florida
Museum of Natural History, University of Florida, Gainesville, Florida 32611, USA. 48Desert Botanical Garden, 1201 N Galvin Parkway, Phoenix, AZ 85281,
USA. 49Instituto de Ecología Aplicada, Universidad Autónoma de Tamaulipas, Calle División del Golfo No 356, Col. Libertad, Cd. Victoria, Tamaulipas C.P
87019, México. 50Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Ciudad Universitaria,
Deleg. Coyoacán, México, D.F. C.P. 04510, Mexico. 51Kushlan Tropical Science Institute, Fairchild Tropical Botanic Garden, 10901 Old Cutler Rd., Coral
Gables, Miami, Florida 33156, USA. 52Botánica y Fitosociología- IADIZA-CCT-CONICET-MENDOZA, Avda. Dr. Adrián Ruiz Leal, S/N°, Parque General San
Martín, C.P. 5500, Mendoza, Mendoza, Argentina. 53Conservation International, 2011 Crystal Drive, Arlington, Virginia 22202, USA. 54Centro de Ecología,
Instituto Venezolano de Investigaciones Cientícas, Carretera Panamericana km 11, Apdo. 20632, Altos de Pipe, Miranda, Venezuela. 55US Fish & Wildlife
Service, 1601 Balboa, Ave., Panama City, Florida 32405, USA. 56Department of Biology, Miami University, 501 East High Street, Oxford, Ohio 45056, USA.
57Facultad de Ciencias Agrarias, UNR, C.C. N° 14, S2125ZAA, Zavalla, Argentina. 58LABIBO, Facultad de Ciencias Naturales, Universidad Nacional de Salta-
CONICET, Av. Bolivia 5150, Salta 4400, Argentina. 59Asociación Etnobotánica Paraguaya, Dr. Hassler 6378 entre R.I.4 Curupayty y R.I. 2 Ytororó, Asunción,
Paraguay. 60Rancho Santa Ana Botanic Garden, 1500 N. College Ave., Claremont, California 91711, USA. 61Museo de Historia Natural, Facultad de Ciencias
Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Peru. 62Jardín Botánico Regional de Cadereyta Ing. Manuel González de Cosío, Consejo de
Ciencia y Tecnología del Estado de Querétaro, Camino a la antigua Hacienda de Tovares sin número, Cadereyta de Montes, Querétaro C.P. 76500, Mexico.
6333 Rossington Road, Shefeld S11 8SA, UK. 64Volcán Toliman 6100, Guadalajara, Jalisco C.P. 44250, Mexico. 65Department of Biology and Biochemistry,
University of Bath, Bath BA2 7AY, UK. 66Al Ain Zoo, Abu Dhabi, United Arab Emirates. 67Sul Ross State University, Alpine, Texas 79832, USA. 68Instituto
Superior Arturo U. Illia(ISAUI), Olsacher 99, Villa Carlos Paz, Córdoba, Argentina. 69Sky Island Alliance, Inc, 300 E. University Blvd., Suite 270, Tucson,
Arizona 85705, USA. 70Herbario BIGU, Escuela de Biología, Facultad CC. QQ. y Farmacia, Universidad de San Carlos de Guatemala, Guatemala. 71The EXSIS
project: cactaceae ex-situ & in-situ conservation, Casilla 175, Buin, Chile. 72Global Environment Facility, 1818 H St NW P4-400, Washington, DC 20433,
USA. 73HLAA, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, UK. 74Departamento de Biología, Universidad Autónoma Metropolitana, Ap. Postal
55-535, México, D.F. 09340, Mexico. Deceased. *e-mail: barbara.goettsch@iucn.org;k.j.gaston@exeter.ac.uk
NATURE PLANTS DOI: 10.1038/NPLANTS.2015.142 ARTICLES
NATURE PLANTS |www.nature.com/natureplants 7
... These dry regions cover almost 17% of the world's landmass and harbor surprisingly high levels of rare and endemic diversity, including some of the most threatened species in the world, yet their biodiversity has been overlooked over the years (Durant et al. 2012;Vanderplank and Ezcurra 2020). Cacti, for example, are central components of the vegetation of American deserts and are considered the fifth most threatened taxonomic group in the world, exhibiting 31% of species listed in a threatened category of the International Union for Conservation of Nature (IUCN) due to persistent anthropogenic pressure (Goettsch et al. 2015;Torres-Silva et al. 2021). These keystone species support much of the desert fauna, providing a wide range of ecosystem services, including food, shelter, pollination, nursery, oviposition substrate, perching and roosting resources (e.g., Fleming and Valiente-Banuet 2002;Drezner 2014). ...
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Desert ecosystems are currently threatened by human activities resulting in the rapid decline of xerophytic plants and specialized fauna. In South America, the demise of cactus species already resulted in the population decline of > 30% of the iconic giant columnar cactus Trichocereus terscheckii. The increasing vulnerability of these keystone species could trigger a cascade of secondary extinctions in highly dependent organisms. Thus, necrotic cacti constitute an important habitat for desert arthropods, yet little is known about the hidden diversity of this neglected niche. We used DNA barcode techniques to survey the diversity of arthropods in a threatened cactus forest dominated by T. terscheckii in northwestern Argentina. We obtained a total of 542 mitochondrial barcode sequences, resulting in 323 Molecular Taxonomic Units (MOTUs) associated to the xerophytic forest and 21 MOTUs exclusive to the giant cactus necrosis. Our results indicated that the area is a biodiversity hotspot within the harsh Andean desert and suggests that nearly 30 species could occur in the decaying cactus, representing the highest richness of cactophilic arthropods recorded in any cactus on the continent to date (6 orders and 16 families). The community structure of cactophilic arthropods showed a phylogenetic clustering pattern, suggesting the coexistence of closely related species. Overall, our study indicates that the giant cactus necrosis sustains a particular phylogenetic diversity of desert arthropods, while demonstrating the efficacy of DNA barcodes for biodiversity assessments in complex and poorly understood ecological systems.
... Mature vegetation is predicted to decrease by 25-60% in biodiversity hotspots between 2005 and 2100 due to the loss of tropical forests alone (Jantz et al. 2015). Overexploitation of species is another serious threat to plants (Goettsch et al. 2015;Phelps and Webb 2015;Sharrock et al. 2014), with an estimated 21.1% of plants assessed for the global IUCN Red List of Threatened Species (hereafter global Red List) reported to be threatened by overexploitation (Nic Lughadha et al. 2020). Habitat loss can increase the impact of overexploitation by reducing the population size and making the remaining population more vulnerable to overexploitation. ...
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Globally, 39% of vascular plant species are estimated to be threatened with extinction. Many factors are responsible for this figure; however, in numerous regions the primary drivers of plant extinction remain unknown. In this study, leaf traits were examined to determine whether there is an association between any specific leaf trait and extinction risk for the Irish flora. Ireland has a relatively small flora that is influenced by a temperate, oceanic climate. Fourteen leaf traits were measured for 1,029 angiosperm taxa, primarily from online herbarium images. Extinction risk was based on national Red List assessments for the Irish flora. Multivariate analysis of the data showed no correlation between leaf traits and extinction risk for the Irish flora. One-way ANOVA and Pearson’s Chi-squared tests largely supported this result, with some indication that leaf teeth may be associated with extinction risk. The correlation of extinction risk and leaf traits with phylogenetic relatedness was also considered, with the presence of a phylogenetic signal detected for the distribution of extinction risk across the Irish flora and significant phylogenetic signal observed for individual leaf traits. It was concluded that the leaf traits analysed do not significantly correlate with the extinction risk of the Irish flora and that leaf traits are not a good predictor of extinction risk for this flora.
... DBG scientists worked with other cactus succulent specialists around the world to complete Red List Assessments. Of the 1478 evaluated species of cacti, nearly 31% were found to be at risk of extinction [63]. DBG is currently working with other members of the Cactus and Succulent Specialist group to assess 300 species of aloes and yuccas, with most of the assessments completed and published by the Red List [64]. ...
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Conservation organizations with common missions can find strength and synergy in collaboration. Collaboration can also be challenging, especially finding the right partnerships or organizations to lead. Within the “ecosystem” of conservation organizations, botanical gardens have a unique array of resources and expertise which make them ideal candidates for leadership or partnership in collaborative conservation efforts. We will explore this idea by examining four conservation initiatives at Desert Botanical Garden (Phoenix, AZ, USA) that approach collaborative conservation on regional, state, and international scales. On a regional scale, Metro Phoenix EcoFlora and the Central Arizona Conservation Alliance lead landscape-level conservation by providing a structure for more than 60 official conservation partners, by generating data, and through public engagement needed in a rapidly developing region. On the state scale, Great Milkweed Grow Out is an initiative for pollinator conservation that provides expertise, materials, and opportunities for a wide range of partners across Arizona. Desert Botanical Garden’s endangered plant species conservation efforts provide expertise and resources through horticulture and seed preservation for threatened and endangered plants across the US and internationally. We will share the structure of each program where applicable, how they came to fruition, and their successes. Through each case study, we will highlight the ways positioning within a botanical garden has benefitted the program and success in collaboration. We will also highlight unique challenges. Botanical gardens provide unique opportunities, and they should not be overlooked when seeking a conservation partner or leader.
... Globose species represent an important part of total cactus richness [5]; therefore, the understanding of this group is important to predict their response to global change. Thirty percent of cactus species are in extinction risk due to human activities [41,42], and particularly due to global change [43,44]. The understanding of species characteristics and the factors that shape them could also be important to predict species responses to global changes. ...
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As a group, cacti are regarded as plants that tolerate water scarcity, since they present a number of adaptations. However, little is known about how species of the family varied their morphoanatomical characteristics along environmental gradients. The aim of this study was to analyze how six Gymnocalycium species occurring in three sites along a precipitation gradient (arid site: G. pugionacanthum, G. marianae; semiarid site: G. hybopleurum, G. stellatum; subhumid site: G. oenanthenum, G. baldianum) differ in their biomass partitioning and morphoanatomical characteristics. We collected mature individuals of each species and analyzed their biomass partitioning (to spines, aboveground stem, underground stem, main root, and lateral and thin roots), morphological characteristics (such as size ratios, spine length and width, and areole density) and anatomical characteristics (stoma number, and cuticle, epidermis, and hypodermis width). Species differed, both qualitatively and quantitatively, in most of the analyzed variables. For example, biomass allocated to spines was highest in G. pugionacanthum, lowest in G. baldianum, and intermediate in the remaining species. However, these variations were not clearly associated with aridity, but were related to the subgenus of the species. These patterns were clearly observed in the PCA. Phylogenetic relatedness is the main factor associated with morphoanatomical characteristics.
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A study was conducted to ascertain the taxonomic validity of the endangered taxon Echinocactus horizonthalonius var. nicholii and whether there may be other groups of populations worthy of subspecies status within the range of the species. To test the hypothesis that individuals of E. horizonthalonius var. nicholii are morphologically distinct from those of the typical variety, a multivariate analysis was done to compare the degree of morphological variation or phenotypic plasticity of stem characters within populations to the variation among populations of E. horizonthalonius throughout its known range. Populations of E. texensis were sampled for outgroup comparison. Discriminant function analysis (DFA) assigning individuals by population showed loose groupings of geographically correlated populations. The DFA assigning individuals to regions or potential subspecific taxa indicated high percentages of correct classification for individuals within populations grouped into the Chihuahuan Desert, Sonoran Desert, and Central Mexican Plateau regions. Taxonomically, these groups correspond to E. horizonthalonius subsp. horizonthalonius (Chihuahuan Desert), E. horizonthalonius var. nicholii (Sonoran Desert), and unnamed taxon of E. horizonthalonius (Central Mexican Plateau). Because these morphological entities are correlated with regional distributions, they are placed here under subspecies, including a newly described taxon, E. horizonthalonius subsp. australis. Because no type for E. horizonthalonius could be located, a neotype is designated.
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Knowledge on the reproductive biology of globose cacti in the genus Mammillaria is incipient, despite being one of the most diverse and threatened groups in Cactaceae. We studied a clonal population of Mammillaria magnimamma (Hawort) located in the Valle del Mezquital, Mexico in which sexual reproduction occurs, although neither seedlings nor juveniles were observed. Based on their short life cycle, globose life form, and melittophilous pollination syndrome, this species was expected to exhibit a mixed mating system and null seed recruitment. We examined the population structure, reproductive phenology, and the mating system by means of controlled-pollination experiments (autonomous self-pollination, manual self-pollination, manual outcross pollination and open pollination). We tested for differences between treatments in the number of seeds per fruit and estimated outcrossing rates. Most (88%) of the M. magnimamma population consisted of clones (10.6 stems/ind) and no juvenile plants or seedlings were recorded. Seed were produced in all the experimental treatments. The average number of seeds per fruit was significantly higher (χ² = 29.52; d.f. = 3; P < 0.0001) in the outcross than the self-pollination treatments. Outcrossing rates estimated from fruits, te, fruits = 0.829, and seeds, te, seeds = 0.8774, showed that M. magnimamma exhibits a mixed mating system. Despite the large number of seed produced, the persistence of these populations likely depends on clonal reproduction. The null recruitment and elevated anthropogenic pressure that this species undergoes across its distribution range threaten its populations.
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The strategic goals of the United Nations and the Aichi Targets for biodiversity conservation have not been met. Instead, biodiversity has continued to rapidly decrease, especially in developing countries. Setting a new global biodiversity framework requires clarifying future priorities and strategies to bridge challenges and provide representative solutions. Hyper-arid, arid, and semi-arid lands (herein, arid lands) form about one third of the Earth's terrestrial surface. Arid lands contain unique biological and cultural diversity, and biodiversity loss in arid lands can have a disproportionate impact on these ecosystems due to low redundancy and a high risk of trophic cascades. They contain unique biological and cultural diversity and host many endemic species, including wild relatives of key crop plants. Yet extensive agriculture, unsustainable use, and global climate change are causing an irrecoverable damage to arid lands, with far-reaching consequences to the species, ground-water resources, ecosystem productivity, and ultimately the communities' dependant on these systems. However, adequate research and effective policies to protect arid land biodiversity and sustainability are lacking because a large proportion of arid areas are in developing countries, and the unique diversity in these systems is frequently overlooked. Developing new priorities for global arid lands and mechanisms to prevent unsustainable development must become part of public discourse and form the basis for conservation efforts. The current situation demands the combined efforts of researchers, practitioners, policymakers, and local communities to adopt a socio-ecological approach for achieving sustainable development (SDGs) in arid lands. Applying these initiatives globally is imperative to conserve arid lands biodiversity and the critical ecological services they provide for future generations. This perspective provides a framework for conserving biodiversity in arid lands for all stakeholders that will have a tangible impact on sustainable development, nature, and human well-being.
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This review examines the historical research progress and areas of vivipary currently investigated in the Cactaceae. Vivipary, a rare attribute, has evolved multiple times in numerous plant lineages; however, a complete understanding of this event is still lacking in the cactus family and plants, in general. This literature search combines the results obtained from scientific sources addressing aspects of vivipary published since 1900 to 2000, with an emphasis from 2000 to 2021. This systematic compendium summarizes findings in various aspects of vivipary, such as the taxonomic and ecological range, offspring survival, and the physiological bases of this phenomenon in the Cactaceae. To date, 77 viviparous taxa circumscribed in subfamilies Pereskioideae and Cactoideae are known, representing approximately 5.4% vivipary at the family level. The taxonomic and geographic occurrence of this facultative reproductive attribute is discussed along with new reports, subsistence of viviparous and non-viviparous progeny, and a framework examining the phylogenetic distribution and putative origin of this generative mode in the family. The portrayal of the geographic distribution of viviparous species highlights the ubiquity of this trait and identifies vivipary hot spots in Cuba, the Brazilian Mata Atlântica, and NW Mexico, emphasizing ideas for cactus conservation. New data dealing with the role of the phytohormones abscisic acid and gibberellic acid in vivipary is examined in conjunction with the thermoregulatory properties of the fleshy viviparous fruits. Research areas deserving further studies are examined and several model species to conduct multidisciplinary research related to cactus vivipary in different areas of the Americas are proposed. Sharable link at: https://rdcu.be/cVUvF
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The Global Strategy for Plant Conservation (GSPC) sets a series of ambitious targets for 2010 to stem the loss of plant diversity. Target 2 calls for a preliminary assessment of the conservation status of all known plant species, at national, regional and international levels, but with less than 3% of global diversity assessed to date, the process must be greatly accelerated. This can best be done by mobilizing plant taxonomists to identify species that are threatened (or potentially threatened) using available distribution data from herbaria and other sources, and by including preliminary IUCN Red List assessments in all their taxonomic works. Emphasis should be placed on rare taxa with restricted ranges, which are the most likely to be at risk. Sufficient data are available for preliminary assessment of nearly all species, thereby limiting the number that must be relegated to "data deficient" status (DD). The taxonomic community can play a unique role in fulfilling the GSPC goals, but we must act quickly.
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Identifying which areas capture how many species is the first question in conservation planning. The Convention on Biological Diversity (CBD) aspires to formal protection of at least 17% of the terrestrial world and, through the Global Strategy for Plant Conservation, 60% of plant species. Are these targets of protecting area and species compatible? We show that 67% of plant species live entirely within regions that comprise 17% of the land surface. Moreover, these regions include most terrestrial vertebrates with small geographical ranges. However, the connections between the CBD targets of protecting area and species are complex. Achieving both targets will be difficult because regions with the most plant species have only slightly more land protected than do those with fewer.
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International trade in species that are or may be endangered by collection from the wild is regulated under the Convention on International Trade in Endangered Species of wild fauna and flora (CITES) for 176 member States (Parties). Internet commerce is a relatively new route for such trade. In 2007, the CITES Secretariat asked Parties to collect information on internet wildlife trade and report problems and implemented regulations. The reports indicated it was difficult to even approximate the influence of e-commerce on CITES-listed species (CITES Secretariat 2009). We report a case study in which we quantified international transactions over an internet auction site of CITES-listed cacti and cross-checked them with CITES trade data. Our results were both surprising and alarming.
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Seagrasses, a functional group of marine flowering plants rooted in the world's coastal oceans, support marine food webs and provide essential habitat for many coastal species, playing a critical role in the equilibrium of coastal ecosystems and human livelihoods. For the first time, the probability of extinction is determined for the world's seagrass species under the Categories and Criteria of the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. Several studies have indicated that seagrass habitat is declining worldwide. Our focus is to determine the risk of extinction for individual seagrass species, a 4-year process involving seagrass experts internationally, compilation of data on species' status, populations, and distribution, and review of the biology and ecology of each of the world's seagrass species. Ten seagrass species are at elevated risk of extinction (14% of all seagrass species), with three species qualifying as Endangered. Seagrass species loss and degradation of seagrass biodiversity will have serious repercussions for marine biodiversity and the human populations that depend upon the resources and ecosystem services that seagrasses provide.
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Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action.