biodiversitate_articol 1

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http://www.countrysideinfo.co.uk/biodvy.htm

Biodiversity and Conservation

by Dr Barbara Corker

Contents

What is Biodiversity?

Losses of Biodiversity

Why ConserveBiodiversity?

Ex Situ Conservation

In Situ Conservation

Conservation at theNational LevelInternationalConservationOverview

What is Biodiversity?

Biodiversity is a modern term which simply means " the variety of life on earth". This variety can bemeasred on several different levels.

Genetic! variation between individals of the same species. This incldes enetic variation betweenindividals in a sinle poplation # as well as variations between different poplations of the samespecies. $enetic differences can now be measred sin increasinly sophisticated techni%es.These differences are the raw material of evoltion.

Species! species diversity is the variety of species in a iven reion or area. This can either bedetermined by contin the nmber of different species present# or by determinin ta&onomic

diversity. Ta&onomic diversity is more precise and considers the relationship of species to each other.It can be measred by contin the nmber of different ta&a 'the main cateories of classification(present. )or e&ample# a pond containin three species of snails and two fish# is more diverse than apond containin five species of snails# even thoh they both contain the same nmber of species.*ih species biodiversity is not always necessarily a ood thin. )or e&ample# a habitat may havehih species biodiversity becase many common and widespread species are invadin it at thee&pense of species restricted to that habitat.
http://www.countrysideinfo.co.uk/biodvy.htmhttp://www.countrysideinfo.co.uk/biodvy.htm#Losses%20of%20Biodiversityhttp://www.countrysideinfo.co.uk/biodvy.htm#Why%20Conserve%20Biodiversity?http://www.countrysideinfo.co.uk/biodvy.htm#Why%20Conserve%20Biodiversity?http://www.countrysideinfo.co.uk/biodvy2.htm#Ex%20Situ%20Conservationhttp://www.countrysideinfo.co.uk/biodvy2.htm#Ex%20Situ%20Conservationhttp://www.countrysideinfo.co.uk/biodvy2.htm#Ex%20Situ%20Conservationhttp://www.countrysideinfo.co.uk/biodvy3.htm#In%20situ%20Conservationhttp://www.countrysideinfo.co.uk/biodvy3.htm#In%20situ%20Conservationhttp://www.countrysideinfo.co.uk/biodvy3.htm#In%20situ%20Conservationhttp://www.countrysideinfo.co.uk/biodvy4.htm#Conservation%20at%20the%20National%20Levelhttp://www.countrysideinfo.co.uk/biodvy4.htm#Conservation%20at%20the%20National%20Levelhttp://www.countrysideinfo.co.uk/biodvy4.htm#International%20Conservationhttp://www.countrysideinfo.co.uk/biodvy4.htm#International%20Conservationhttp://www.countrysideinfo.co.uk/biodvy4.htm#Summaryhttp://www.countrysideinfo.co.uk/biodvy.htmhttp://www.countrysideinfo.co.uk/biodvy.htm#Losses%20of%20Biodiversityhttp://www.countrysideinfo.co.uk/biodvy.htm#Why%20Conserve%20Biodiversity?http://www.countrysideinfo.co.uk/biodvy.htm#Why%20Conserve%20Biodiversity?http://www.countrysideinfo.co.uk/biodvy2.htm#Ex%20Situ%20Conservationhttp://www.countrysideinfo.co.uk/biodvy3.htm#In%20situ%20Conservationhttp://www.countrysideinfo.co.uk/biodvy4.htm#Conservation%20at%20the%20National%20Levelhttp://www.countrysideinfo.co.uk/biodvy4.htm#Conservation%20at%20the%20National%20Levelhttp://www.countrysideinfo.co.uk/biodvy4.htm#International%20Conservationhttp://www.countrysideinfo.co.uk/biodvy4.htm#International%20Conservationhttp://www.countrysideinfo.co.uk/biodvy4.htm#Summary


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Ecosystem! Commnities of plants and animals# toether with the physical characteristics of theirenvironment 'e.. eoloy# soil and climate( interlin+ toether as an ecoloical system# or,ecosystem,. -cosystem diversity is more difficlt to measre becase there are rarely clearbondaries between different ecosystems and they rade into one another. *owever# if consistent

criteria are chosen to define the limits of an ecosystem# then their nmber and distribtion can alsobe measred.

*ow many species are there?

-stimates of lobal species diversity vary enormosly becase it is so difficlt to ess howmany species there may be in less well e&plored habitats sch as ntoched rain forest. ainforest areas which have been sampled have shown sch ama/in biodiversity 'nineteen trees

sampled in 0anama were fond to contain 1#233 different beetle species alone4( that the mindboles over how many species there miht remain to be discovered in ne&plored rain forest areasand microhabitats.

$lobal species estimates rane from 2 million to 133 million species. Ten million is probably nearerthe mar+. Only 1.5 million species have been named. Of these# appro&imately 263#333 are plants and763#333 are insects. New species are continally bein discovered every year. The nmber ofspecies present in little!+nown ecosystems sch as the soil beneath or feet and the deep sea canonly be essed at. It has been estimated that the deep sea floor may contain as many as a millionndescribed new species. To pt it simply# we really have absoltely no idea how many species thereare4

Losses of Biodiversity

-&tinction is a fact of life. 8pecies have been evolvin and dyin ot eversince the oriin of life. One only has to loo+ at the fossil record to appreciatethis. 'It has been estimated that srvivin species constitte abot 19 of thespecies that have ever lived.(

*owever# species are now becomin e&tinct at an alarmin rate# almostentirely as a direct reslt of hman activities. 0revios mass e&tinctionsevident in the eoloical record are thoht to have been broht abotmainly by massive climatic or environmental shifts. :ass e&tinctions as adirect conse%ence of the activities of a sinle species are nprecedented

in eoloical history.

The loss of species in tropical ecosystems sch as the rain forests# is e&tremely well!pblicised andof reat concern. *owever# e%ally worryin is the loss of habitat and speciescloser to home inBritain. This is arably on a comparable scale# iven the mch smaller area involved.

0redictions and estimates of ftre species losses abond. One sch estimate calclates that a
http://www.countrysideinfo.co.uk/habitats.htm#habitat%20losseshttp://www.countrysideinfo.co.uk/habitats.htm#habitat%20losses


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%arter of all species on earth are li+ely to be e&tinct# or on the way to e&tinction within ;3 years.or flpandemics and


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If poplations become too small# then simply findin a mate# or interbreedin# can becomeserios problems.

#igratory species

8pecies which need sitable habitats to feed and rest in widely spaced locations 'which areoften traditional and ,wired, into behavior patterns( are very vlnerable to loss of these ,waystations,.

Species "ith e$ceptionally comple$ life cyclesIf completion of a particlar lifecycle re%ires several different elements to be in place at veryspecific times# then the species is vlnerable if there is disrption of any sinle element in thecycle.

Specialist specieswith very narrow re%irements sch as a sinle specific food sorce# e..a particlar plant species.

Loss of an individal species can have varios different effects on the remainin species in anecosystem. These effects depend pon the how important the species is in the ecosystem. 8omespecies can be removed withot apparent effect# while removal of others may have enormos effectson the remainin species. 8pecies sch as these are termed "keystone" species.

%hy Conserve Biodiversity&

Ecological 'easons

Individal species and ecosystems have evolved over millions of years into a comple&

interdependence. This can be viewed as bein a+in to a vast >isaw p//le of inter!loc+in pieces. Ifyo remove enoh of the +ey pieces on which the framewor+ is based then the whole pictre maybe in daner of collapsin. We have no idea how many +ey ,pieces, we can afford to lose before thismiht happen# nor even in many cases# which are the +ey pieces. The ecoloical arments forconservin biodiversity are therefore based on the premise that we need to preserve biodiversity inorder to maintain or own life spport systems.

Two lin+ed isses which are crrently of reat ecoloical concern inclde world!wide deforestation and lobal climate chane.

)orests not only harbor ntold nmbers of different species# bt also play a critical

role in relatin climate. The destrction of forest# particlarly by brnin# reslts inreat increases in the amont of carbon in the atmosphere. This happens for tworeasons. )irstly# there is a reat redction in the amont of carbon dio&ide ta+en inby plants for photosynthesis and secondly# brnin releases he %antities ofcarbon dio&ide into the atmosphere. 'The 17 fires in IndonesiaEs rain forests aresaid to have added as mch carbon to the atmosphere as all the coal# oil andasoline brned that year in western -rope.( This is sinificant becase carbon


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dio&ide is one of the main reenhose ases implicated in the crrent lobalwarmin trend.

'Climate Chane Information(


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prodction of new varieties of crops. If all these are lost# then or crop plants also become morevlnerable to e&tinction.

There is an ecoloical caveat here of corse. Whenever a wild species is proved to be economicallyor socially sefl# this atomatically translates into frther loss of natral habitat. This arises eitherthroh lare!scale cltivation of the species concerned or its indstrial prodctionF harvestin. Bothre%ire space# inevitably provided at the e&pense of natral habitats.

0erhaps the rain forests and the seas shold be allowed to +eep their secrets.

Ethical 'easons

=o we have the riht to decide which species shold srvive and which shold die ot?

=o we have the riht to case a mass e&tinction?

:ost people wold instinctively answer ,No4,. *owever# we have to realise that most biodiversitylosses are now arisin as a reslt of natral competition between hmans and all other species forlimited space and resorces.

If we want the l&ry of ethics# we need to redce or poplations.

(esthetic 'easons

:ost people wold aree that areas of veetation# with all their attendant life forms# are inherentlymore attractive than brnt# scarred landscapes# or acres of concrete and bildins. Who woldn,tprefer to see btterflies dancin above colored flowers# rather than an indstrial comple& belchinsmo+e?

*man well!bein is ine&tricably lin+ed to the natral world. In the western world# he nmbers ofpeople confined to lare rban areas derive reat pleasre from visitin the contryside. The ability todo so is rearded not so mch as a need# bt as a riht. National overnments mst therefore >lethe conflictin re%irements for more hosin# indstry and hiher standards of livin with demands

for contryside for recreational prposes.

)o" do "e Conserve Biodiversity&

There are two main ways to conserve biodiversity. These are termed ex situ (i.e. out of the natural

habitat) and in situ (within the natural habitat)


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E$ Situ Conservation! out of the natural habitat

Species*based!

+oos! These may involve captive breedin prorammes#

(uaria! research# pblic information and edcation

-lant Collections ! breedin prorammes and seed storae

+S

In the past# /oos were mainly display facilities for the prpose of pblic en>oyment andedcation.


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33 species. 0oplations of this si/e are >st lare enoh to avoid inbreedin effects. *owever#/oos are now shiftin their emphasis from lon!term holdin of species# to retrnin animals to thewild after only a few enerations. This frees p space for the conservation of other species.

$enetic manaement of captive poplations via std records is essential to ensre enetic diversityis preserved as far as possible. There are now a variety of international compterised std recordsystems which cataloe enealoical data on individal animals in /oos arond the world. :atincan therefore be arraned by compter# to ensre that enetic diversity is preserved and in!breedinminimised 'always assmin the animals involved are prepared to co!operate(.

esearch has led to reat advances in technoloies for captive breedin. This incldes techni%essch as artificial insemination# embryo transfer and lon!term cryoenic 'fro/en( storae of embryos.These techni%es are all valable becase they allow new enetic lines to be introdced withothavin to transport the adlts to new locations. Therefore the animals are not even re%ired to co!operate any loner. *owever# frther research is vital. The sccess of /oos in maintaininpoplations of endanered species is limited. Only 2A of 275 species of rare mammals in captivity aremaintainin self!sstainin poplations 'World esorces Institte(.

'eintroduction of species to the "ild poses several different problems.

Diseases

The introdction of new diseases to the habitat# which can decimate e&istin wild poplations.st spplyin it.

Genetic 'aces

eintrodced poplations may be of an entirely different enetic ma+e!p to oriinalpoplations. This may mean that there are sinificant differences in reprodction habits andtimin# as well as differences in eneral ecoloy. eintrodction of individals of a species intoan area where the species has previosly become e&tinct# is in many cases >st li+eintrodcin a foreiner. The Lare Copper Btterfly is a ood e&ample of this.


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)abitat

The habitat mst be there for reintrodction to ta+e place. In many cases# so mch habitat hasbeen destroyed# that areas mst first be restored to allow captive poplations to bereintrodced. 8itable e&istin habitats will also 'nless the species is e&tinct in the wild(sally already contain wild members of the species. In this case# it is li+ely that within thehabitat# there are already as many individals as the habitat can spport. The introdction ofnew individals will only lead to stress and tension as individals fiht for limited territory andresorces sch as food. In this case# nothin positive has been accomplished byreintrodction# it has merely increased the stress on the species. It may even in some casesreslt in a decrease in nmbers. In contrast# the provision of additional restored habitat nearbycan allow wild poplations to e&pand into it withot the need for reintrodction.

(/0('1(

The role of a%aria has larely been as display and edcational facilities. *owever# they areassmin new importance in captive breedin prorammes. $rowin threats to freshwater species inparticlar# are leadin to the development of ex situbreedin prorammes. The World Conservationnion 'ICN( is crrently developin captive breedin prorammes for endanered fish. Initially thiswill cover those from La+e Gictoria in


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< more serios problem with ex situ collections involves aps in coverae of important species#particlarly those of sinificant vale in tropical contries. One of the most serios aps is in the areaof crops of reional importance# which are not widely traded on world mar+ets. These often haverecalcitrant seeds 'nsited to lon!term storae( and are poorly represented in botanic collections.Wild crop relatives are also nder!represented. These are a potential sorce of enes conferrinresistance to diseases# pests and parasites and as sch are a vital ene ban+ for commercial crops.

0lant enetic diversity can also be preserved ex situthroh the se of seed ban+s. 8eeds are smallbt toh and have evolved to srvive all manner of adverse conditions and a host of attac+ers.8eeds can be divided into two main types# orthodo& and recalcitrant. Orthodo& seeds can be driedand stored at temperatres of !23oC.


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-rotected sites, or 'eserves

In situconservation maintains not only the enetic diversity of species# bt also the evoltionaryadaptations that enable them to adapt continally to shiftin environmental conditions# sch aschanes in pest poplations or climate. In situconservation also ensres that alon with taretspecies# a host of other interlin+ed species are also preserved as a by!prodct. It is enerallycheaper than ex situmethods 'althoh not cheap(. It may often be the only conservation option# fore&ample for species with recalcitrant seeds.

In situ conservation measres involve desinatin specific areas as protected sites. 0rotection maybe offered at varios levels# from complete protection and restriction of access# throh varios levelsof permitted hman se. In practice# complete protection is rarely necessary or advisable in aterrestrial conte&t. *man beins have been a ma>or part of the landscape for many thosands ofyears. Over the corse of that time# hman cltres have emered and adapted to the localenvironment# discoverin# sin and alterin biotic resorces. :any areas that now appear natralEbear the hallmar+s of millennia of hman inflence. Other species have evolved alon with thatinflence and in many cases re%ire the distrbance provided by hmans to provide the necessaryconditions for their srvival. In other words# it is rarely advisable to releate the contryside to thestats of a msem piece.

This applies particlarly in the less economically developed areas of the world# where in many cases#the livelihood of the local people depends on sin the natral resorces available to them.0rohibitin the se of sch resorces in protected areas means that e&pensive enforcementmeasres sally have to be pt in place. It is far better to involve local people in conservation and tofind creative ways for them to ma+e a sstainable livin while still protectin valable habitats orspecies.

The biosphere reserve concept has been developed throh the :an and Biosphere ':


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:arine reserves may be vital tools in preservin species!rich areas sch astropical coral reefs# which are bein devastated by non!sstainable fishinmethods in many areas. The rationale of sch reserves is not to loc+ away fishfrom fishermen# bt rather to create refes inside which poplations can bildp and spill over to repoplate ad>acent areas.

:arine eserves need to be careflly desined to ta+e into accont# movement patterns# dispersalrates and poplation dynamics of particlar taret species. )or e&ample# it wold be pointless havina reserve where the resident species relarly travelled to non!protected areas. It wold also bepointless protectin the habitat of an adlt# bt nelectin the eoraphically different breedinronds and habitats of >veniles# or vice versa. 8ch factors shold also be ta+en into considerationin the desin of terrestrial reserves.

Management of Nature Reserves

Natre reserves are sally desinated to protect a particlar species#assemblae of species# or

specific habitats.


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becase species cannot mirate to repoplate the area. estoration may rely heavily pon speciesmaintained by ex situ methods and is an e&ample of the complementary natre of in situand ex situtechni%es.

'EC4E'5 6 3)'E(3E2ED S-EC1ES

The recovery of threatened species enerally hines on providin sitable habitat and conditions inwhich they can thrive. :ost biodiversity losses can be directly attribted to habitat loss# so provisionof habitat is often the +ey re%irement for recovery of a species. The dormose ' Muscardinusavellanarius(is a ood e&ample of this.

=ormice are the sb>ect of a species recovery proram sponsored by -nlish Natre. They thrive indecidos woodland and overrown hederows. They are arboreal and re%ire networ+s ofinterlin+in low branches to provide aerial hihways to food sorces 'e.. ha/el nts andhoneysc+le(. In former times# the practice of coppicin woodland 'cttin trees near to rond level

and then allowin them to reenerate nmeros shoots( provided ideal conditions for dormice.*owever# coppicin is little practised these days# with the reslt that lare areas of former habitathave become nsitable for dormice. ecovery therefore hines on providin sitable areas for thespecies.

=ormice also sffer from competition with an introdced species# the rey s%irrel. Both speciescompete for the food resorce of ha/el nts.

123'D0CED S-EC1ES

The vast ma>ority of e&otic introdced species die ot becase they are nsited to local conditions.

< few however# appear to be sperbly adapted to particlar local conditions and will tend to ot!compete native species.

elatory policies are necessary to crb the introdction of e&otic species and enetic resorces# asthe conse%ences can be disastros. Introdced species can wipe ot innmerable other localspecies. Between 1A7 and 172# an


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GE2E31C #D161C(312

*mans now have the technoloy to alter life on earth in a totally ni%e way. $enetic enineerincan involve the transfer of enetic material between widely separated ta&onomic rops. e.. $enesfrom a fish have been introdced into tomatoes. -ntirely new species can intentionally ornintentionally be prodced. There is no arantee that all the reslts will be beneficial or can evenbe controlled.

LEG(L -'3EC312

Natre reserves need to be properly protected from the adverse reslts of hman activity.This miht be indirect# as in for e&ample# habitat deradation throh polltion broht abot by

activities elsewhere. st to have laws# there mst also be the will andthe resorces to enforce them. -ven in economically developed nations# the necessary resorces toproperly enforce laws are not always made available. In nder!developed nations# even the mostbasic resorces for enforcement may be lac+in. In addition# national laws may not in the end

translate into local action# in which case they do not accomplish mch. In democratic nations#national laws are also driven to a lare e&tent by pblic opinion. They may in some cases be draftedmore as a response to emotion than by actal scientific need.

8everal international conventions e&ist for the preservation of biodiversity. These inclde schconventions as the amsar Convention '17A( which provides for the conservation of internationallyimportant wetlands and the Bern Convention '17( which re%ires the protection of endanered andvlnerable species of flora and fana in -rope and their habitats. There are many others. 8inatory


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nations to these conventions mst ratify national laws to ensre compliance with the conventions.

In Britain# the main piece of leislation coverin conservation is the Wildlife and Contryside


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The ature o! "evon # A Biodiversity Action Planis =evonEs response to this national biodiversityplannin process. This reional process is oin on throhot -nland. The sm of all the reionalBiodiversity ects are in the lon rnremains to be seen. Loss of habitat is still the most pressin problem.

In some areas# biodiversity is seriosly threatened as a reslt of trade in endanered species. Theinternational trade in wildlife is estimated to be worth J12 billion a year. p to a %arter of that trade isalmost certainly illeal. The main piece of leislation limitin trade in endanered species is CIT-8'the Convention on International Trade in -ndanered 8pecies(. This is a N convention which came

into effect in 176. CIT-8 prohibits commercial trade in endanered species of plants and animals.Leitimate international trade in species which are not now threatened# bt which may become so iftrade is not controlled# is allowed via a permit system. esponsibility for implementin it lies withsinatory nations.

:any of the problems involved in protectin habitats and species arise becase local people eitherneed to se the resorces available in sensitive habitats to provide the necessities for sbsistence orsrvival# or traditionally have always done so. N-8CO 'nited Nations -dcational# 8cientific andCltral Oranisation(# throh its ,:an and the Biosphere, proramme# has set p a nmber ofInternationally reconised biosphere reservesin an attempt to address this problem.

vervie"

The world has a vast rane of different species which are all ine&tricably lin+ed. The eminentnatralist and television presenter# 8ir =avid


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We can only ess at many of the interactions ta+in place within habitats. While we have come alon way in or +nowlede of the natral world# we need to reconise that we are still fndamentallyinorant. With reconition of this inorance comes the nderstandin that we need to preserve wholehabitats intact# so that the comple&ity of interactions remains# whether we nderstand them or not.

The fate of the entire planet is now dependent pon a sinle species ! hmans. This isnprecedented in the -arthEs 5.7 billion year history. ltimately# conservation of biodiversity will hinepon the control of hman poplations. Continally e&pandin hman nmbers have led to anescalatin competition with wildlife for the space re%ired to hose everyone# as well as to prodceenoh food to feed them. Increasin standards of livin also re%ire that frther natral areas andresorces are iven over to sstainin western lifestyles and associated demands.

We are interferin with biodiversity on a reat many levels# from the moleclar 'enetic modification(#all the way throh habitats and possibly lobal climate chane as well. *owever# the manypredictions made abot species and habitats losses need to be careflly e&amined in each case and

not >st ta+en at face vale. :any are based on compter simlations and emotions can et in theway of clear practical thin+in.

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