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Rare and endemic species: Why are they prone to extinction?

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Abstract: A species is considered to be “rare” if it exhibits any one of the following attributes: (1) naturally occurs in a narrow geographical area, (2) occupies only one or a few specialised habitats, (3) forms only small population(s) in its range. An “endemic” species, however, grows naturally in a single geographical area, the size of which could be either narrow or relatively large. Not all endemic species are rare, just as not all rare species must necessarily be endemic. Many rare and/or endemic species exhibit one or more of the following attributes which make them especially prone to extinction: (1) narrow (and single) geographical range, (2) only one or a few populations, (3) small population size and little genetic variability, (4) over-exploitation by people, (5) declining population sizes, (6) low reproductive potential, (7) the need for specialised ecological niches, (8) growth that requires stable and nearly constant environments. When habitats of a rare and/or endemic species are damaged and/or fragmented by various human activities, the distribution ranges and population sizes of the species will be reduced, leaving them vulnerable to extinction at a much higher rate than other comparable species. Species that experience any of the above attributes must be given priority and monitored and managed carefully in an eff ort to promote genetic conservation.
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K. IŞIK
411
Turk J Bot
35 (2011) 411-417
© TÜBİTAK
doi:10.3906/bot-1012-90
Rare and endemic species: why are they prone to extinction? *
Kani IŞIK**
Biology Department, Science Faculty, Akdeniz University, 07058, Antalya - TURKEY
Received: 11.12.2010
Accepted: 12.02.2011
Abstract: A species is considered to be “rare” if it exhibits any one of the following attributes: (1) naturally occurs in a
narrow geographical area, (2) occupies only one or a few specialised habitats, (3) forms only small population(s) in its
range. An “endemic” species, however, grows naturally in a single geographical area, the size of which could be either
narrow or relatively large. Not all endemic species are rare, just as not all rare species must necessarily be endemic.
Many rare and/or endemic species exhibit one or more of the following attributes which make them especially prone to
extinction: (1) narrow (and single) geographical range, (2) only one or a few populations, (3) small population size and
little genetic variability, (4) over-exploitation by people, (5) declining population sizes, (6) low reproductive potential,
(7) the need for specialised ecological niches, (8) growth that requires stable and nearly constant environments. When
habitats of a rare and/or endemic species are damaged and/or fragmented by various human activities, the distribution
ranges and population sizes of the species will be reduced, leaving them vulnerable to extinction at a much higher rate
than other comparable species. Species that experience any of the above attributes must be given priority and monitored
and managed carefully in an e ort to promote genetic conservation.
Key words: Rare species, endemism, extinction, population, conservation biology
Nadir ve endemik türler yok-oluş olayına niçin duyarlıdır?
Özet: Bir tür şu üç özellikten herhangi birini taşırsa, o tür “nadir tür” olarak düşünülür. (1) Doğal olarak küçük bir
coğra k alanda bulunursa, (2) yalnızca bir veya birkaç özelleşmiş habitatta (yaşama ortamında) yetişirse, (3) yayılma
alanında yalnızca küçük populasyon(lar) halinde bulunursa. Öte yandan bir “endemik tür” ise tek bir coğra k alanda
yetişen türdür, ama bu coğra k alan küçük bir alan olabildiği gibi geniş bir alan da olabilir. Her endemik tür, nadir tür
değildir. Aynı şekilde her nadir tür de endemik tür olmayabilir. Nadir ve endemik türlerin çoğu, aşağıdaki özelliklerden
birini veya birçoğunu gösterebilirler. (1) Küçük (ya da tek bir) coğra k bölgede yetişmek, (2) yalnızca bir veya birkaç
populasyona sahip olmak, (3) populasyonların küçük olması ve çok az genetik çeşitlilik göstermesi, (4) insanlar
tarafından aşırı ölçüde avlanılması ya da hasat edilmesi, (5) populasyonun gittikçe azalan bir eğilim göstermesi, (6)
üreme potansiyelinin düşük olması, (7) özelleşmiş ekolojik nişlere ihtiyaç duymaları, (8) kararlı, durağan ve değişime
duyarlı bir çevrede yetişmeleri. Bu özellikler, nadir ve endemik türlerin yok-oluş olayına karşı özellikle duyarlı olmasına
yol açar. Nadir ve endemik türlerin yaşama ortamları değişik insan etkinlikleriyle bozulursa ya da bu ortamlar parçalara
bölünürse, önce bu türlerin dağılış alanları ve populasyon büyüklükleri azalmakta, sonra da bu türler, diğer türlere
kıyasla yok-oluşa doğru daha hızlı gitmektedir. Yukarıda belirtilen özelliklerden herhangi birine veya birden fazlasına
sahip olan türler genetik kaynakların korunması çalışmalarında öncelikle ele alınmalı ve dikkatlice izlenip yönetilmelidir.
Anahtar sözcükler: Nadir tür, endemik tür, yok-oluş, populasyon, koruma biyolojisi
Research Article
* Paper submitted at the International Symposium on the Biology of Rare and Endemic Plant Species (BIORARE Symposium), 26-29
May 2010, Fethiye, Muğla - Turkey.
** E-mail: kani@akdeniz.edu.tr
Rare and endemic species: why are they prone to extinction?
412
Introduction
In this article, I will  rst de ne the concepts related
to rare and endemic species.  e common features
of extinction prone species will then be discussed,
followed by the path that leads to the extinction of a
species.  is information will hopefully provide the
main basis for establishing strategies for biological
conservation.
Generally speaking, if a species demonstrates any
of the following characteristics, it is considered a rare
species: (a) grows naturally in a narrow geographical
area, (b) occupies only one or few specialised habitats,
(c) forms only small population(s) in its range. At the
opposite end of these criteria lie the species that are
called common (cosmopolite) and/or abundant.
An endemic species, however, is the one that
grows naturally only in a single geographic area, the
size of which could be either narrow or relatively
large. A species may be both rare and endemic if
it lives in a narrow (and single) geographical area
(Primack, 2006).
Depending on the scale of the geographic range,
endemic species are called by a variety of di erent
names. For example, an endemic species may be
restricted only to a small, local geographic area, in
which case it is called a “local endemic.” As the size
of the geographic range become larger, an endemic
species may labelled “provincial endemic” (restricted
within the borders of a province), “national endemic”
(grows only within the borders of a nation),
or “regional endemic” (grows only in a certain
geographical region). When the distribution range of
a species is restricted only to a single continent and
not found in any others, as is the case for many plant
and animal species in Australia, then one can also
talk about a “continental endemic.”
e following examples can be instructive for
each of the above cited endemism types. Sternbergia
candida Mathew et T.Baytop (Liliaceae fam.), for
example, is a local endemic that grows naturally
only within the borders of Fethiye (Muğla, Turkey)
and its neighbourhoods. Centaurea dursunbeyensis
Uysal & Köse is another example of a local endemic
which grows naturally in limestone crevices around
Dursunbey (Balıkesir) (Uysal and Köse, 2009).
Anthemis ammophila Boiss. et Heldr. (Asteraceae
fam.) (Antalya daisy) is an example of a provincial
endemic species, found naturally in several localities
all of which are within the borders of the Antalya
province in Turkey. Crocus ancyrensis (Herbert) Maw
(Iridaceae fam.) grows in many localities in the central
Anatolian region of Turkey and its neighbourhoods.
Since it is restricted to the borders of a single nation,
however, it is considered a national endemic species.
Pancratium maritimum L. (Amaryllidaceae fam.) (sea
da odil) is a regional endemic of the Mediterranean
basin since it grows naturally in the coastal sands
of many countries along the Mediterranean Sea.
Finally, a well known pine species, Pinus sylvestris L.
(Pinaceae fam.), is a good example of a continental
endemic because it naturally grows only in Eurasia.
eplacement of rare and endemic species in a
three-dimensional (3-D) space
e features listed below are the 3 important
criteria that determine the conservation status
of a species.  ese are: (a) geographic range, (b)
population size, and (c) habitat demands. Figure 1
illustrates the relationships among these criteria in a
3-D space.  e geographic range of a species may be
very narrow, very wide, or anywhere in between these
extreme ranges (X, on horizontal axis) (Figure 1).  e
population size of a species may also range from very
small to very large (Y, on vertical axis) (Figure 1).
Similarly, the habitat demand or habitat preference of
a species may be very speci c (specialised species), or
general (generalist species) (Z, the third dimension)
(Figure 1).
If a species is both rare and endemic, by de nition,
it is located in the very lower le corner of the 3-D
space.  e rectangular 3-D space bordered by broken
lines along the X axis represents rare species with
a small population size and rather speci c habitat
requirements but a relatively wide geographic range.
Similarly, the rectangular 3-D space along the Y axis
represents rare species with restricted geographic
range and rather speci c habitat requirements
but a relatively large population size. Finally, the
rectangular 3-D space along the Z axis represents
rare species with restricted geographic range and a
small population size but relatively moderate habitat
demands.
Any species located on the lower le corner of the
3-D space (i.e. species that are both rare and endemic)
K. IŞIK
413
needs the highest and most immediate rescue actions
in conservation programs. Any species located on
the upper far right corner of the 3-D space can be
considered a generalist, with rather wide distribution
range and very large population size. Such species are
in very low risk of extinction and usually they are not
of immediate concern for conservation purposes.
IUCN conservation categories
e IUCN (International Union for Conservation
of Nature) has established 9 categories of species
(Figure 2) (IUCN, 2001).  ese categories are
useful as a diagnostic tool to determine the risk of
extinction and establish conservation strategies for
the involved species. As data become available and
information accumulates on a species (by taxonomic
experts, conservationists, and other biologists), its
conservation status is constantly being re-evaluated
(www.iucnredlist.org) (Ekim et al., 2000). It is also
possible that a species considered to be extinct could
be re-discovered a er several years, causing its IUCN
conservation status to be re-evaluated (Kandemir,
2009).
e expressions below need clari cation to
prevent confusion in following the IUCN categories.
A species is considered extinct when no member of
the species remains alive anywhere in the world.  e
expression “extinct in the wild” refers to species in
which individuals remain alive only in captivity or
small
l
arge
Population
size, y
narrow
wi
d
e
Geographic range, x
genera
l
is
t
specia
l
ist
Ha
b
itat pre
f
erence, z
Figure 1. ree dimensional (3-D) illustration showing the
place of rare and/or endemic species in relation to its
geographic range (X axis), population size (Y), and
habitat demands (Z).
reatened
(CR, EN, VU)
Lower risk
(NT, LC)
Data
decient
(
DD
)
Extinct
(EX, EW)
Extinct,
Extinct in the wild
Near threatened,
Least concern
Critically endangered,
Endangered,
Vulnerable
Adequate
data
Inadequate
data
Evaluated
SPECIES
Not
evaluated
Not
evaluated
(NE)
Figure 2. IUCN Conservation (or Red List) categories. De ning such categories helps
to determine extinction risk and establish conservation strategies for the
involved species. (Redrawn by the author, based on information in IUCN
2001.)
Rare and endemic species: why are they prone to extinction?
414
under human care, and no subjects are present in
natural habitats. A “locally extinct” or “extirpated”
species refers to a species which is no longer found
in an area where it used to live before although it still
lives elsewhere in the wild.
Common features of extinction prone species
Species that exhibit one or more of the following
features are vulnerable to extinction (Primack, 2006):
a - Species with a narrow (or single) geographic
range,
b - Species with only one or few populations,
c - Species with a small population size,
d - Species with a declining population size,
e - Species hunted or harvested by people,
f - Species with low reproductive ability and/or
germplasm-dispersal-ability,
g - Species that require specialised habitat and
niche conditions.
e above listed characteristics of extinction-
prone species are generally not independent of one
another. For example, species with specialised niche
requirements also tend to have a small population size.
Species that face the full range of these characteristics
are the ones that are most vulnerable to extinction.
Each of these groups is brie y discussed below.
a - Species with a narrow (or single) geographic
range: As the geographic range of a species become
larger, the probability of its extinction becomes
smaller (Figure 3). For example,  omas et al. (2004)
estimated that more than one million species, mainly
those with narrow ranges, could become extinct by
2050, merely as a result of global climate change.
Among the species with comparable geographic
ranges, those with special niche and habitat
requirements are more vulnerable to extinction than
those less demanding (generalist) species. Similarly,
species with a smaller population size have a higher
probability of extinction than those with larger
population sizes (Figure 3). 
b - Species with only one or few populations: is
category is related to the previous one, because
species with only one or few populations will also
tend to have a narrow or single geographical range.
Species with only a single population remaining
obviously have greater risk of extinction than those
with more than one population. Any chance factor,
such as a disease or the intrusion of human activity,
may result in habitat destruction, population decline,
and the eventual extinction of a species with only one
or few populations.
c - Species with a small population size: Small
populations may pose a number of di culties for a
species.  ey are likely to have low genetic variability
and experience inbreeding depression. Furthermore,
they are more vulnerable to environmental changes
and demographic variation.  erefore, small
populations are more likely to go locally extinct.
Lande (1988) has also discussed the genetic and
demographic consequences of small population
sizes in greater detail. A long term study by Jones
and Diamond (1976) on bird species living in
the Channel Islands o the coast of California
showed that extinction rates decrease as the size of
the breeding population increases. For example,
populations with fewer than 10 breeding pairs had
about a 40% probability of extinction over 80 years,
whereas populations with 100 breeding pairs had
about 10% probability of extinction. It can be seen,
then, that populations with more than 100 breeding
pairs have a very low probability of extinction.
ese ndings are also relevant for botanical
studies. A study on a plant species, Ipamopsis aggregate
(Pursh.) V. Grant, reported that seed germination in
small populations was considerably lower than that
seen in relatively large populations (Heschel & Paige,
1995).
Small
Large
Local Provncal Natonal Regonal Contnental Global
Geographc Range
1.0
C
A
A: Average trend
B: Specalsed and/or Small popns
C: Generalsts and or Large popns
0.0
Pr. Extncton
Figure 3. Probability (Pr.) of extinction of species depending on
the size of the geographic range.
K. IŞIK
415
A theoretical study on an idealised population
at various e ective population sizes (N
e
) has
indicated that loss of genetic variability is higher
over time in smaller populations than it is in larger
populations (Groom et al., 2006). For example, a er
10 generations there was a loss of genetic variability
of about 40% with an e ective population size of 10, a
loss of 65% with an e ective population size of 5, and
95% loss occurred with an e ective population size
of 2.  e main reason for this loss was genetic dri ,
which o en operates in small populations (Groom et
al., 2006).
Reduced genetic variability means greater
susceptibility to various deleterious genetic
processes such as inbreeding depression, the loss of
evolutionary potential, and the loss of the ability to
adapt to changing conditions. Each of these factors,
either alone or in combination, may contribute to
a decline in population size, which, in turn leads
to eventual extinction (Frankham, 2005). Several
other genetic and non-genetic factors that a ect the
population size, genetic diversity, and adaptation of a
species are summarised in Figure 4.
d - Species with declining population size: A
population may be large, but show signs of decline
over time. Unless the cause(s) of decline is identi ed
and corrected, the  nal outcome is a small population
size and, ultimately, the related problems that such
populations face (Figure 4).
e - Species hunted or harvested by people: Over-
exploitation (over-harvesting or over-hunting) can
rapidly reduce the population size of a species. If the
harvesting is not regulated by national laws, local
ethics, and/or international regulations (such as
CITES), the species can be driven to extinction. For
example, a study on a medicinal plant by Ghimire et
al. (2005) showed that recovery of original density was
very slow in the years following intensive harvesting
(75% and 100% reduction of original density). When
no harvesting was permitted, however, this situation
was able to change quickly; density levels increased
to about twice that of the original density a er 3 years
of no harvesting.
f - Species with low reproductive ability and/or
germplasm-dispersal-ability: Species with low biotic
(reproductive) potential and low dispersal ability
(particularly in species with a larger size) are more
prone to extinction. In plants, species with large and/
or short-lived seeds are more vulnerable than those
with smaller, long-lived seeds (Kolb & Diekmann,
2005). Species that are able to produce both by seeds
and clonal means have a higher chance of survival.
In the face of changing environments (either
human-induced or natural), a species has to either
migrate to suitable habitats or adapt to the new
habitat conditions. Otherwise, the species will go
extinct. It should be kept in mind, however, that
the rate of adaptation (i.e. genetic changes) is o en
far behind (and unable to catch up with) the rate of
rapid human-induced environmental changes. For
this reason, species that are unable to disperse and
colonise new areas have a higher risk of extinction.
g - Species that require specialised habitat and
niche conditions: Species with a low tolerance range
(those with specialised niche requirements) have a
greater tendency to become extinct when changes
occur in the environment. Examples of these types
of species include wetland plants, plants with speci c
pollinators, and plants that require speci c dispersal
agents.
Many species are found in stable environments
where human disturbance is minimal, such as old
stands, core areas of forests, and wild pastures
(pastures with no cultivation). Facing changes in the
physical and chemical environments of such areas,
Mgraton
GEOGRAPHIC
RANGE
Harvestng,
Huntng
POPULATION
SIZE
GENETIC
DIVERSITY
ABILITY TO ADAPT TO
CHANGING ENVIRONMENTS
(SURVIVAL + GROWTH +
REPRODUCTION RATE)
Habtat loss
and
fragmentaton
Reproductve
behavour,
Inbreedng
Polymorphc
genes
Mutaton rate
Figure 4. Factors a ecting population size, genetic diversity, and
adaptation.
Rare and endemic species: why are they prone to extinction?
416
certain species are unable to adapt and fail to rebuild
their populations fast enough to avoid extinction.
e path to extinction (4 Ds)
ere are 4 processes, which can be thought of as
the 4 Ds, that follow each other in subsequent order
before extinction takes place.  ese are destruction,
degradation, decline, and,  nally, disappearance
(extinction). Species vulnerable to extinction are
more susceptible and more rapidly a ected by each
of these processes. Figure 5 summarises the diversity
of human activities and associated events that
contribute to the 4 D process.
Summary and conclusion
Many rare and/or endemic species have one or
more of the following characteristics: (1)  ey have
a narrow (or single) geographical range, (2) they
have only one or a few populations remaining, (3)
they show small population size and little genetic
variability, (4) they are usually over-exploited (over-
hunted and over-harvested) by people, (5) they
exhibit declining population sizes, (6) they have low
reproductive ability, (7) they show specialised niche
demands, (8) they grow in stable and nearly constant
environments. All of these attributes, either alone or
in combination, make a species prone to extinction
at an increased rate. When habitats of a rare and/or
endemic species are damaged and/or fragmented by
mismanagement and various other human activities,
the distribution ranges, population sizes, and genetic
variability of the species will be reduced and its
members will become vulnerable to extinction at a
faster rate than other species. Species with any one
or more of the above attributes must be carefully
monitored and managed in an e ort to maintain
biodiversity.
Acknowledgements
Special thanks are extended to 2 anonymous
reviewers for their constructive criticism, and to Dr
Özge Tufan Çetin and Yusuf Kurt, who helped in
xing the  gures in the paper. Akdeniz University
Scienti c Research Project Unit, Antalya, provided
partial support to the study.
Increasng human populaton, ncreasng consumpton
Dversty of human actvtes
Agrculture,
loggng,
fsheres
Industry and
fossl fuel use
Urbansaton and
road constructon
Internatonal
trade
Habtat loss, habtat
degradaton, habtat
fragmentaton,
polluton (N, P, …),
land cover change,
Overexplotaton
Introducton of
nvasve
speces and
dsease
Clmate change
Degradaton of ecosystems,
Eroson of genetc dversty and evolutonary potental,
Loss of ecosystem servces,
Eroson of lfe-support systems for human socetes
Loss of bologcal dversty,
Extncton of speces and populatons
(Modfed from Groom et al., 2006)
Figure 5. Major forces that threaten biological diversity and that lead to the
extinction of a species.
K. IŞIK
417
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... They, however, suffer from a series of human practices, including development, deforestation, conversion of habitats to agricultural land, over-grazing and tourism (McNeely, 2003;Inskipp & Baral, 2010;Lobo-Araújo et al., 2024). Rare and Endemic species can be especially vulnerable to extinctions due to their low density and greater vulnerability to changes in the environment (Işik, 2011). Endemic species have limited geographic distributions and require specific habitats, making them especially sensitive to habitat change (Işik, 2011). ...
... Rare and Endemic species can be especially vulnerable to extinctions due to their low density and greater vulnerability to changes in the environment (Işik, 2011). Endemic species have limited geographic distributions and require specific habitats, making them especially sensitive to habitat change (Işik, 2011). Slight shifts in land cover caused by deforestation, urbanization, or agricultural development can dramatically limit accessible habitat, putting its existence at risk (Meyer & Turner, 1992). ...
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  • May 2025
The White-naped Tit ( Machlolophus nuchalis ) is a vulnerable bird endemic to India that faces serious threats due to habitat loss, degradation, and fragmentation of habitat. Using MaxEnt niche modelling and compiled species occurrence data, we predicted White-naped Tit's habitat suitability in India's arid and semi-arid biogeographic zones. Our analysis suggests that 6.74 % (~50,612 km²) of the total area is suitable for White-naped Tit. Land cover change detection reveals that rangelands that contain suitable habitat types, support the preferred flora of Acacia spp. and have the high frequency of sightings for the target species, are the most declining form of land cover in the study area. Our findings help to provide a baseline understanding of the White-naped Tit's range and its association with land cover and other physical factors, which may be taken in consideration for short- and long-term conservation management approaches for this threatened species
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... A species is considered rare if it is infrequently encountered or has a small number of individuals in a specific locality. A rare species usually has a small local population, a narrow geographical distribution range and restricted habitats (Rabinowitz, 1981;Işik, 2011). ...
... Rarity and small local populations are characteristics of ecological communities. Such rare species are vulnerable to local extinction (Işik, 2011). Globally, about 30% of tree species are threatened with extinction (BGCI, 2021). ...
Propagation of locally rare and threatened tree species for conservation
Technical Report
Full-text available
  • Jan 2025
The high diversity of tropical forests is mainly contributed by the high richness of rare species. Rare species are characterized by small populations and are often threatened with local extinction because of stochastic forces and human disturbances. However, locally rare species are often overlooked in conservation priorities. Like many diverse tropical forests, the rich tree diversity of Jalthal remnant forest is mainly due to the occurrence of large number of rare tree species. Besides stochastic and intrinsic forces, the rare trees of Jalthal are threatened by overexploitation, forest fires, invasive alien plant species and uninformed management practices. Protection of existing individuals and the translocation of nursery-grown seedlings into the forest are among the most appropriate and necessary strategies for the conservation of rare tree species in Jalthal. However, nurseries in Nepal are mainly focused on horticulture and garden species, some commercially important forest species, selected medicinal plants and exotic species, visibly neglecting the rare and threatened tree species. In this context, we have established a local nursery at Jalthal to carry out seed germination trials of rare tree species. We conducted germination experiments on seven selected rare tree species of Jalthal forest from February 2023 to October 2024. We collected the fruits of the selected species, from which the seeds were then manually or mechanically extracted, counted and sown in seedbed or polypots under nursery conditions. We monitored the germination of seeds of each species on a daily basis, noted germination type and recorded the germination process for three months after the first case of germination. All the selected species in our nursery were germinated with different germination percentages. We achieved a high germination percentage of more than 80% in Baccaurea ramiflora, Dillenia indica and Garcinia xanthochymus, and the least in Horsfieldia kingii (16.67%). Germination success was moderate in Camphora tenuipilis, Cycas pectinata and Garcinia cowa. We have provided a brief taxonomic account of each species, followed by information on threats to the species in Jalthal, fruits/seeds collection time, seed extraction, seed sowing time, sowing method, germination time and germination percentage. We have also highlighted the challenges associated with the germination of rare species’ in nurseries. We underscore need of further trials to increase the germination success of species with low and moderate germination percentages. Furthermore, we urge different nurseries in the country to produce seedlings of native and rare tree species. This document will serve as a guiding document in the conservation of rare trees for conservationists, nurserymen, restoration practitioners and forest enthusiasts far beyond Jalthal’s boundaries.
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... Most endemic species possess a combination of characters such as limited distributions, small population sizes, unique genetic reserves, specific habitat requirements, and reduced dispersal capacities. Consequently, the presence of the abovementioned characteristics in endemic species increases their vulnerability to a high risk of endangerment or even extinction (Işik 2011;Khajoei Nasab, Mehrabian et al. 2024;Khajoei Nasab, Shakoori et al. 2024;Zeraatkar and KhajoeiNasab 2024;Liao et al. 2023). ...
Future of Three Endemic Woody Species of Colutea (Fabaceae) in a Changing Climate in Iran
Article
Full-text available
  • May 2025
Woody plants offer valuable services to ecosystems, including providing useful products, stabilizing ecosystems, and mitigating climate and pollution effects. However, they face significant abiotic and biotic stresses, with climate change being the most critical challenge. It is essential to understand that reducing populations of woody species, particularly those found only in a specific area, can have severe and irreversible effects on the entire ecosystem. Therefore, exploring the potential influence of climate change on the distribution of endemic woody species is an appealing subject for conservation researchers. This study investigates how climate change affects the distribution of three endemic species of woody plants in the genus Colutea in Iran. The MaxEnt model was used to analyze the data, and the results showed that the model was effective for predicting the impact of climate change on the plants (AUC ≥ 0.9). The distribution of C. persica was significantly affected by solar radiation, Precipitation of Wettest Month, sand, and silt content. C. porphyrogamma's distribution was impacted by Mean Temperature of Coldest Quarter, Precipitation of Driest Month, and Cation Exchange Capacity, while C. triphylla was most affected by Precipitation Seasonality, Precipitation of Driest Quarter, and Isothermality. According to the findings, the distribution of these species is expected to decrease in the 2050s and 2070s due to climate change, based on the RCP4.5 and RCP8.5 climate scenarios. These findings can be useful for developing strategies to manage the impacts of climate change on these species.
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... Rapid and profound changes in vegetation are occurring, reducing the reserves and habitats of many species (Kelly 2008). It is predicted that the number of plants threatened with extinction, including endemic and rare species, will increase (Burlakova 2011, Işik 2011. These species are priority targets for conservation as carriers of a unique gene pool. ...
Distribution of the endemic species Astragalus babatagi Popov and growth characteristics of the plant in the Conditions of Tashkent (Uzbekistan)
Article
Full-text available
  • Apr 2025
Ethnobotany Research and Applications 30:56 (2025)-http://dx. Abstract Background: Astragalus plants, due to their medicinal properties, are widely used in traditional medicine across various cultures. Endemic and rare species represent a particularly vulnerable category due to intensive and unsustainable harvesting of raw materials. Among them is Astragalus babatagi Popov, a member of the genus Astragalus in the family Fabaceae. Like other species of this genus, it is a rich source of biologically active compounds such as cycloartane glycosides and flavonoids. One of the ways to conserve this category of medicinal plants is through cultivation.
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... A further limitation of GBIF data here was that, whilst most climate types in this study occurred infrequently, this was not reflected in sampling; the GBIF WS cells did not occur in any of the rarest climate types, despite both being most prevalent in South Africa. This risks missing species that may be specialised to infrequent climatic conditions and, in the case of such habitat specificity, at risk on multiple fronts: smaller geographic range, few populations and specialised niche conditions (Işik 2011). It is intuitive that mobilising more records FIGURE 6 | Smoothed kernel density estimate of the distribution of climate rarity scores, between 0 (common) and rare (1), for the GBIF set (a) and the combined set (c), with the y-axis representing relative density. ...
Mobilisation of Data From Natural History Collections Can Increase the Quality and Coverage of Biodiversity Information
Article
Full-text available
  • Apr 2025
The surge of biodiversity data availability in recent decades has allowed researchers to ask questions on previously unthinkable scales, but knowledge gaps still remain. In this study, we aim to quantify potential gains to insect data on the Global Biodiversity Information Facility (GBIF) through further digitisation of natural history collections, assess to what degree this would fill biases in spatial and environmental record coverage, and deepen understanding of environmental bias with regard to climate rarity. Using mainland Afrotropical records for Catharsius Hope, 1837 (Coleoptera: Scarabaeidae), we compared inventory completeness of GBIF data to a dataset which combined these with records from a recent taxonomic revision. We analysed how this improved dataset reduced regional and environmental bias in the distribution of occurrence records using an approach that identifies well‐surveyed spatial units of 100 × 100km as well as emerging techniques to classify rarity of climates. We found that the number of cells for which inventory completeness could be calculated, as well as coverage of climate types by ‘well‐sampled’ cells, increased threefold when using the combined set compared to the GBIF set. Improvements to sampling in Central and Western Africa were particularly striking, and coverage of rare climates was similarly improved, as not a single well‐sampled cell from the GBIF data alone occurred in the rarest climate types. These findings support existing literature that suggests data gaps on GBIF are still pervasive, especially for insects and in the tropics, and so, is not yet ready to serve as a standalone data source for all taxa. However, we show that natural history collections hold the necessary information to fill many of these gaps, and their further digitisation should be a priority.
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... The presence of endemic species in critical danger of extinction has been confirmed by several authors. There are 13 endemic species in critical danger of extinction due to their narrow distribution area and small population [19]. Some species with restricted distribution require greater conservation efforts, and some rarer species could be farmed in their natural environment to maintain their population. ...
Endemic Fish Species in West Africa: Description, Spatial Distribution and Risk of Extinction Due to Global Change
Chapter
Full-text available
  • Feb 2025
West Africa is crossed by several major rivers, including Niger, Senegal, Volta, and Gambia. These rivers, along with their tributaries and deltas, and the coastal zone form a complex fluvial network that supports a variety of aquatic habitats and significant biodiversity. The aquatic ecosystems of West Africa are characterized by high biodiversity and strong connections to local livelihoods. In this study, a total of 112 fish, belonging to 27 families and 19 orders, have been recorded in West African countries. This includes one elasmobranch (Raja herwigi) and 111 actinopterygians. Guinea ranks first with 34% of the species, followed by Nigeria with 19%, and Cape Verde with 15%. Siluriformes dominate with 32% of the species, followed by Cypriniformes with 19%, and Cyprinodontiformes with 15%. Mochokidae has the highest number of endemic species, followed by Cyprinidae and Nothobranchidae. A total of 12 families each have only one endemic species. Benthopelagic species dominate, followed by demersal species. Freshwater species dominate with 83% of the total, marine species account for 18%, and one species (Limbochromis robertsi) inhabits both freshwater and brackish water. Most endemic species have low vulnerability to fishing while 12% are critically endangered. More than half are at risk. This situation calls for conservation policies.
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... Endangered and rare species are defined as those whose populations are significantly reduced or whose distribution is severely restricted, placing them at a high risk of extinction in the near future. These species are often characterized by a narrow geographical range, limited to one or a few specialized habitats, and are vulnerable to over-exploitation, habitat loss, and the effects of climate change and human activities [1]. Despite their vulnerability, rare and endangered species, particularly plants, play crucial roles in ecosystems, contribute to health care and scientific research, and hold both economic and cultural value [2][3][4]. ...
Potential Distribution and Response of Camphora longepaniculata Gamble (Lauraceae) to Climate Change in China
Article
Full-text available
  • Feb 2025
Camphora longepaniculata is an endangered evergreen tree listed as National Class II Protected Tree Species in China, highly valued for its medicinal and economic importance. Currently, research on this species has primarily focused on its pharmaceutical properties, while its potential distribution and responses to climate change remain insufficiently explored. In this study, 36 valid occurrence records and 11 environmental variables were utilized to predict its potential distribution and assess its response to future climate scenarios. The MaxEnt model revealed that the current distribution of C. longepaniculata largely aligns with its predicted suitable habitats, with the primary range located in Sichuan Province. Furthermore, this model identified the highly suitable habitats to be predominantly concentrated in Sichuan and Shaanxi Provinces under climate change. Among the environmental variables, annual precipitation (bio12), minimum temperature of the coldest month (bio6), and elevation (dem) were the most influential, collectively contributing over 70% to the model’s predictive accuracy. Future climate projections compared to the current distribution suggest a northward expansion of suitable habitats for C. longepaniculata, although Sichuan Province is predicted to remain the core habitat under future scenarios. Kernel density analysis of occurrence points indicated that the largest concentration of distribution points is near the Sichuan Basin, reinforcing the importance of this region as a stronghold for the species. Based on the results of potential distribution and kernel density analysis, in situ conservation, artificial cultivation, and the establishment of wild protected areas and local germplasm banks are recommended for stable, suitable habitats, such as Sichuan Province and parts of Yunnan and Guizhou Provinces. This study not only sheds light on the potential geographical distribution of C. longepaniculata and its response to climate change but also provides a scientific basis for the development of targeted conservation strategies for this species.
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KOOPTASI Gambusia spp. TERHADAP Aplocheilus panchax DI HABITAT ASLINYA: MINI-REVIEW THE COOPTATION OF Gambusia spp. TO Aplocheilus panchax AT ITS NATIVE HABITAT: MINI-REVIEW
Article
Full-text available
  • Apr 2025
Abstrak Aplocheilus panchax (Hamilton, 1822), salah satu spesies ikan yang tersebar luas di berbagai perairan dan ditemukan sebagai spesies endemik di wilayah Oriental. Namun, keberadaan A. panchax di habitat aslinya berpotensi terancam oleh keberadaan spesies invasif, yaitu Gambusia spp. Mini-review ini bertujuan untuk mengelaborasi informasi terkait potensi invasi Gambusia spp. terhadap habitat dan sumber daya yang dimiliki A. panchax sehingga dapat menyebabkan kepunahan A. panchax sebagai endemic species, native species, atau indigenous species di lingkungan aslinya. Hasil mini-review menunjukkan kemampuan hidup dan adaptasi dari Gambusia spp. sebagai spesies invasif atau spesies alien menjadi kekuatan baginya untuk mengkooptasi sumber daya di suatu habitat perairan. Hal ini terlihat pada kemampuan Gambusia spp. dalam beradaptasi melalui sistem pencernaan, pernafasan dan osmoregulasi, serta reproduksi yang sama atau bahkan lebih baik dibandingkan A. panchax. Kemampuan ini dapat membahayakan eksistensi ikan lokal (indigenous species), asli (native spesies), atau endemik (endemic species) yang memiliki sifat seperti Gambusia spp., salah satunya adalah A. panchax. Spesies A. panchax yang selama ini keberadaannya belum mendapatkan perhatian yang dibuktikan dengan status konservasi Least Concern (LC), perlu mendapatkan perhatian lebih di habitat aslinya. Status konservasi tersebut seharusnya perlu direview ulang dikarenakan adanya potensi keterancaman dari ikan invasif seperti Gambusia spp. serta potensi kerusakan ekosistem dan habitatnya. Proses domestikasi perlu dilakukan untuk meningkatkan produksi dan produktivitas A. panchax sehingga dapat meningkatkan populasi dan mendukung upaya konservasi. Abstract Aplocheilus panchax (Hamilton, 1822), one of the fish species widely distributed in various waters and found as an endemic species in the Oriental region. However, the existence of A. panchax at its native habitat is potentially threatened by the presence of invasive species, namely Gambusia spp. This mini-review aimed to elaborate on information related to the potential invasion of Gambusia spp. at the A. panchax's habitat and resources, which can lead to the extinction of A. panchax as an endemic species, native species, or indigenous species at its native environment. The results of the mini-review showed the ability of Gambusia spp. as an invasive species or alien species to adapt and occupy resources in a aquatic habitat. This was evident in the ability of Gambusia spp. to adapt through its digestive, respiratory, and osmoregulatory systems, as well as its reproductive abilities, which were equal to or even better than those of A. panchax. This ability could threaten the existence of local species (indigenous species), native species, or endemic species that have characteristics similar to those of Gambusia spp., one of which is A. panchax. The species A. panchax, whose existence has not received attention, as evidenced by its conservation status of Least Concern (LC), needs more attention at its native habitat. This conservation status should be reviewed again due to the potential threat from invasive fish such as Gambusia spp. and the potential destruction for its ecosystem and habitat. Domestication processes need to be carried out to increase the production and productivity of A. panchax, thereby increasing its population and supporting conservation efforts.
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Plant species likely to be extinct
Article
  • Mar 2025
  • J NAT CONSERV
Understanding plant extinctions is crucial for effective conservation planning because they pose risks to other organisms, ecosystems, and human well-being. In the present study, we highlighted plant species that are likely to be extinct by analyzing all plant species categorized by the IUCN Red List as Critically Endangered with “Possibly Extinct” tags (CR (PE)). Our aims are to provide data on i) plant species likely extinct, ii) their distribution across regions, ii) threats to these species, and iv) their protection. After screening for rediscovery, synonymization with extant taxa, and presence in ex-situ collections, we recorded a total of 474 species categorized as CR (PE). The majority (93.25%) of the species were assigned to the CR (PE) category using criterion B of the IUCN Red List Criteria, which is primarily based on the species’ geographic range. The plant family with the highest number of likely extinct species was Lauraceae with 74 species. These likely extinct species were mostly trees reported to be found in the tropics, including islands. The most prominent threat that placed plant species into the CR (PE) category was habitat degradation and conversion. Clear understanding of extinction status is crucial for effective conservation planning. Therefore, comprehensive assessments, including targeted surveys and probabilistic modeling, should be carried out. This will help determine which species are genuinely CR rather than Extinct (EX), ensuring that conservation actions, when implemented, are truly impactful.
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Endemic Species of Himalayan Region in Sikkim
Chapter
  • Feb 2025
Himalayas covers about five countries named as: India, China, Nepal, Bhutan and Pakistan. Mount Everest is the highest peak located in the Himalaya (27°59′N 86°55′E). Himalayan range is bordered on the north-west by Karakoram and Hindu Kush ranges, TibetanPlateau and Indo-Gangetic Plain. Some rivers like the Indus, the Ganges and the Tsangpo-Brahmaputra emerged from the vicinity of the Himalayas. There are different and unique type of species found in the flora and fauna of Himalayan region. Some of these species are endemic and critically endangered. Snow leopard is the main predator found at high altitudes but fall in endangered category. There are many biodiversity hotspots, 353 new species that includes 242 plants, 16 amphibians, 16 reptiles, 14 fishes, 2 birds, 2 mammals and more than 61 invertebrates have been found in the eastern Himalaya in the year between 1998–2008.In Sikkim, the climate varies from sub-tropical in the south to tundra in the north and the average annual temperature in most of the area of Sikkim is about 18 °C. For the protection of the biodiversity in Sikkim the government made many protected areas such as Khangchendzonga National Park, Maenam wildlife sanctuary, Shingba Rhododendron sanctuary etc. The present study is based on the vulnerability of endemic species found in the Sikkim area covers the Himalayan region due to climate change. Sikkim contains different types of plant and animal species which are of great economic importance. The livelihood of people was mostly dependent upon it. There is total 48 plant species and 20 animal species present in the flora and fauna of Sikkim are endemic due to deforestation, illegal poaching, global warming and some climate factors etc. Sikkim had lost 123 ha of its natural forest which is equal to 66.8 kt of CO2 emissions. There is an urgent need of conservation of the biodiversity through various methods such as creation of protected areas, captive breeding and reintroduction or by increasing awareness among public for sustainable use of species.
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A New Centaurea L. (Asteraceae) Species from Turkey
Article
Full-text available
  • Dec 2009
A new Centaurea L. (Asteraceae) species from Turkey is described and illustrated. Centaurea dursunbeyensis Uysal & Köse exists on limestone crevices in ancient Dursunbey Forest (Balikesir) in western Anatolia. It belongs to C. sect. Phalolepis (Cass.) DC., and taxonomically its closest relatives are C. aphrodisea Boiss. and C. cadmea Boiss. Diagnostic morphological characters from very similar taxa are provided, and a key is provided that includes related species of sect. Phalolepis from Turkey. The geographical distribution of the new species and species of other related taxa of the same section are mapped. The chromosome number of C. dursunbeyensis, 2n = 36, counted in root tips, is also reported and illustrated.
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Conservation of Himalayan medicinal plants: Harvesting patterns and ecology of two threatened species, Nardostachys grandiflora DC. and Neopicrorhiza scrophulariiflora (Pennell) Hong
Article
Full-text available
  • Aug 2005
  • BIOL CONSERV
Himalayan medicinal plants are threatened by large scale exploitation for trade. Research applicable to their sustainable use is largely lacking. We analyze the effects of different harvesting patterns on the population ecology of two highly threatened Himalayan medicinal plants, Nardostachys grandiflora (Valerianaceae) and Neopicrorhiza scrophulariiflora (Scrophulariaceae), in Shey-Phoksundo National Park and in its buffer zone in northwestern Nepal. We first documented local harvesting approaches of two major user groups, amchi (traditional doctors trained in Tibetan medicine), who harvest plants in a selective manner for local health care purposes, and commercial collectors, who harvest unselectively and at much higher intensity for trade. We then applied the selective harvesting approach of amchi in an experiment to test the effects of different harvesting levels on the population ecology of these two species. These experiments revealed a positive effect of low harvesting levels on plant density, but recruitment and survival rates decreased with increasing harvesting levels. We also analyzed the effect of high harvesting pressure for trade on the population ecology of N. grandiflora. Recruitment and survival rates were higher in N. scrophulariiflora than in N. grandiflora; the latter species is more vulnerable to harvesting than the former. The difference between them in sustainability of harvest is related to differences in their strategies of vegetative reproduction and in harvesting practices associated with these strategies. Management of Himalayan medicinal plants can be improved by taking harvesting patterns, plant life forms and growth patterns into consideration.
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The Rediscovery of Some Taxa Thought to Have Been Extinct in Turkey
Article
  • Jan 2009
This paper reports the re-discovery of Barbarea auriculata Hausskn. ex Bornm. var. auriculata (Brassicaceae), Onobrychis nitida Boiss. (Fabaceae), Onosma discedens Hausskn. ex Bornm. (Boraginaceae), and Silene oligotricha Hub.-Mor. (Caryophyllaceae). All of these taxa had been listed as Extinct (EX), according to the World Conservation Union Red List Categories. This study provides the re-descriptions of these taxa, presents field observations of these taxa, and suggests new IUCN categories.
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Short-Time-Base Studies of Turnover in Breeding Bird Populations on the California Channel Islands
Article
  • Dec 1977
The number and identities of species coexist-ing at a particular locality are not fixed for-ever, but result from dynamic interplay be-tween local extinctions and immigrations. While this dynamic structure must apply to any local community, it is particularly con-venient to study on islands, because of their sharp boundaries. In their well-known theory of island biogeography MacArthur and Wil-son (1963, 1967) proposed that the number of species on an island approaches an equilibrium between extinctions and immigrations, and that populations are subject to turnover. It is likely that large differences in turnover rates will be found if one compares the same taxo-nomic groups on islands of different area, iso-lation, latitude, and habitat, or if one compares different species on the same island. The measurement and understanding of these dif-ferences is beginning to emerge as a major empirical and theoretical problem, as a problem in assessing the importance of group selection and understand-ing the evolution of social behavior (Levins 1975, Wilson 1975:1X-116), and as a major practical problem in conservation strat-egy (Terborgh 1974a, 197413, Diamond 1975, 1976, Wilson and Willis 1975, Sullivan and Shaffer 1975). A convenient situation for studying these problems is provided by the land and fresh-water breeding birds of the Channel Islands off the coast of southern California. The eight islands of this group vary in area (A) from 2.6 to 249 km2, in distance from the mainland (d) from 20 to 98 km, and in number of land and non-swimming water bird species breed-ing in a given year (S,,,,) from 7 to 39 (see Philbrick 1967, Power 1972, Johnson 1972, and Jones 1975 for maps and table of areas and dis-tances). As of 1917, when A. B. Howell' s monograph Avifauna of the Islands off the Coast of Southern California was published, 170 species of birds had been recorded from the Channel Islands. By 1976 this number had increased to 325. All but five of these 155 additions were of non-breeding visitors, re-corded principally by us and by other observ-ers since 1968. The reason is that most of the early ornithologists who visited these islands were collectors and oologists mainly interested in obtaining specimens or egg sets of the breeding birds, some of which are considered endemic or nearly endemic subspecies. Conse-quently, the breeding avifauna of all the Chan-nel Islands was more thoroughly documented by 1917 than was the non-breeding avifauna (see appendix p. 545 for discussion). In 1968 one of us (J. D.) visited each of the Channel Islands l-3 times, plus the nearby Mexican island group Los Coronados, to sur-vey the breeding avifaunas for comparison with the surveys summarized by Howell (1917). On each island he found that there had been turnover, reflected both in dis-appearances of some former breeding popula-tions and in breeding presence of some for-merly absent or non-breeding species. A brief account of the results, and of estimated turn-over rates in relation to A, d, and Serl, was pub-lished (Diamond 1969). One of Diamond' s findings was that some breeding populations had immigrated and become extinct several times on the same island between the early 1909' s and 1968. Thus, surveys separated by many decades must have underestimated turn-over rates and might only have revealed the tip of the iceberg of community dynamics (see Diamond and May in press for examples). For organisms as mobile as birds, and islands as close to the mainland as the Channel Is-lands, it is likely that there will always be a long waiting list of potential immigrants; many more unsuccessful attempts at colonization than attempts that succeed even briefly; and many more brief successes and rapid failures than foundings of a colonist population that survives a long time. Hence repeated surveys at one-year intervals were clearly required to reveal the dynamic structure of the avifauna more accurately. Such studies of turnover at one-year intervals have the further advantage of reducing interpretative problems associated with habitat changes and effects of man which develop over longer intervals.
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Inbreeding Depression, Environmental Stress, and Population Size Variation in Scarlet Gilia (Ipomopsis aggregata)
Article
Despite a large body of theory, few studies have directly assessed the effects of variation in population size on fitness components in natural populations of plants We conducted studies on 10 populations of scarlet gilia, Ipomopsis aggregata, to assess the effects of population size and year-to-year variation in size on the relative fitness of plants. We showed that seed size and germination success ave significantly reduced in small populations (those less than or equal to 100 flowering plants) of scarlet gilia Plants from small populations are also more susceptible to environmental stress. When plants from small and large populations were subjected to an imposed stress (combined effects of transplanting and experimental clipping, simulating ungulate herbivory) in a common garden experiment plants from small populations suffered higher mortality and were ultimately of smaller size than plants from large populations. In addition experimental evidence indicates that observed fitness reductions are genetic, arte to the effects of genetic drift and/or inbreeding depression When pollen was introduced from distant populations into two small populations, seed mass and percentage of germination were bolstered while pollen transferred into a large population had no significant effect. Year-to-year variation in population size and its effects on plant fitness are also discussed In one small population, for example, a substantial increase in size from within did not introduce sufficient new (archived) genetic material to fully overcome the effects of inbreeding depression.
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Effects of Life‐History Traits on Responses of Plant Species to Forest Fragmentation
Article
Knowing the general principles of plant-environment relationships is required to be able to predict changes in species occurrence and abundance in changing landscapes. Because habitat fragmentation may affect the dispersal, establishment, and persistence of species in various ways, we expected associations between species life-history traits related to these processes and their responses to fragmentation. We tested (1) whether groups of plant species with specific biological attributes are especially affected by forest fragmentation and (2) whether regionally rare species are more negatively affected than more common species. We surveyed 145 deciduous forest patches in northwestern Germany for the presence of a large set of forest plant species. For each of 82 species, we collected data on eight life-history traits and estimated species' responses to decreased patch size and increased distance to other occupied forest patches. We classified species into two emergent groups that differed strongly with respect to most considered life-history traits. The group of species that was more negatively affected by isolation mostly consisted of clonal forest specialist species characterized by few and heavy diaspores, lack of dispersal structures, small size, short-lived seeds, and insect pollination. There was no effect of patch area. Univariate analyses revealed (marginally) significant relationships between species' responses to isolation and diaspore number and mass, plant height, and habitat preference and between responses to patch area and seed-bank longevity, plant height, and habitat preference. Regional frequency of occurrence was not correlated to species' responses to fragmentation and did not differ between the two emergent groups. Rare species, however, were smaller and produced fewer and shorter-lived diaspores than common species. Forest fragmentation may thus threaten species differently, depending on their specific biological characteristics. Approaches based on life-history traits potentially allow prediction of species' responses to habitat fragmentation and may therefore aid in the assessment of the endangerment of plant species and ultimately in the conservation of biological diversity. Resumen: Se requiere conocimiento de los principios básicos de las relaciones planta-ambiente para predecir cambios en la ocurrencia de especies en paisajes cambiantes. Debido a que la fragmentación del hábitat puede afectar la dispersión, establecimiento y persistencia de las especies de varias maneras, esperábamos asociaciones entre características de la historia de vida relacionadas con estos procesos y sus respuestas a la fragmentación. Probamos (1) si grupos de especies de plantas con atributos biológicos específicos son especialmente afectados por la fragmentación del bosque y (2) si especies regionalmente raras son afectadas más negativamente que las especies más comunes. Examinamos 145 parches de bosque deciduo en el noroeste de Alemania para buscar un conjunto grande de especies de plantas de bosque. Para cada una de 82 especies, recolectamos datos de ochos características de la historia de vida y estimamos la respuesta de las especies al decremento del tamaño del parche y al incremento de la distancia a otros parches de bosque. Clasificamos a las especies en dos grupos emergentes, con diferencias notables en la mayoría de las características consideradas. El grupo de especies que fue afectado más negativamente por el aislamiento consistió principalmente de especies clonales especialistas de bosque caracterizadas por diásporas escasas y pesadas, carencia de estructuras dispersoras, tamaño pequeño, semillas de vida corta y polinización por insectos. No hubo efecto de la superficie del parche. Análisis univariados revelaron (marginalmente) relaciones significativas entre las respuestas de las especies al aislamiento y el número y masa de las diásporas, la altura de plantas y la preferencia de hábitat y entre respuestas a la superficie del parche y la longevidad del banco de semillas, la altura de plantas y la preferencia de hábitat. La frecuencia de ocurrencia regional no se correlacionó con las respuestas de las especies a la fragmentación y no hubo diferencia entre los dos grupos emergentes. Sin embargo, las especies raras fueron más pequeñas y produjeron diásporas más pequeñas y menos longevas que las especies comunes. Por lo tanto, la fragmentación del bosque puede amenazar a las especies de manera diferente, dependiendo de sus características biológicas específicas. Los métodos basados en características de la historia de vida potencialmente permiten la predicción de las respuestas de las especies a la fragmentación del hábitat y por lo tanto pueden ayudar a la evaluación del peligro de extinción de una especie de planta y, a la postre, a la conservación de la diversidad biológica.
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Genetics and Extinction. Biol Conserv
Article
  • Nov 2005
  • BIOL CONSERV
The role of genetic factors in extinction has been a controversial issue, especially since Lande’s paper [Genetics and demography in biological conservation, Science 241 (1988) 1455–1460] paper in Science. Here I review the evidence on the contribution of genetic factors to extinction risk. Inbreeding depression, loss of genetic diversity and mutation accumulation have been hypothesised to increase extinction risk. There is now compelling evidence that inbreeding depression and loss of genetic diversity increase extinction risk in laboratory populations of naturally outbreeding species. There is now clear evidence for inbreeding depression in wild species of naturally outbreeding species and strong grounds from individual case studies and from computer projections for believing that this contributes to extinction risk. Further, most species are not driven to extinction before genetic factors have time to impact. The contributions of mutation accumulation to extinction risk in threatened taxa appear to be small and to require very many generations. Thus, there is now sufficient evidence to regard the controversies regarding the contribution of genetic factors to extinction risk as resolved. If genetic factors are ignored, extinction risk will be underestimated and inappropriate recovery strategies may be used.
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