Ékologi

Ékologimangrupa cabangélmunu ngulik sebaran jeung ayanamahluk hirup,habitat, jeung interaksi antara maranéhna sartalingkunganana— nu ngawengku boh unsur-unsurabiotik(teu hirup) saperticuacajeunggéologi, jeung unsurbiotiksapertispésiés. Istilah ieu diwanohkeun dina taun1866ku biolog JérmanErnst Haeckel, nyokot tinabasa Yunanioikosnu hartina "imah" jeunglogos
Ékologi manusamangrupa disiplin akademik nu patali tapi béda, ngulikkamanusaan, kagiatan spésiésna nu teratur, jeung lingkunganana; raket pisan hubunganana jeung ékologi biologis,sosiologi, ogé disiplin séjénna.
Di saluareun kontéks ilmiah, kecapékologimindeng dipaké salaku sinonim pikeun "lingkunganana", nyaéta reureujeunganana sakur organisme liar nu lolobanaana hirup dina tata sarta lingkungan aslina, kalawan saeutik pangaruh manusa; utamana nu patali jeung naon baé kapentinganmanusa—ékonomis,médis,éstétis,hédonistik, séntiméntal, jsb... Harti ieu biasana dilarapkeun nalika urang nyebutkeun yén hiji barang/kagiatan mibanda ajén hadé atawa goréng pikeun "ékologi", jeung naékologi politis.
Nu séjén bisa ngalarapkeun kecapékologilain dina maksud élmu, tapi salaku sistemfilosofisatawa malahagamis, nu nunjukkeun hiji sawangan ngeunaan mayapada jeung ajén-inajén husus sarta ajén moral — misalna yén totalitas hirup mangrupa hiji sistem kohérén, nu meureun aya tujuanana; yén punahna spésiés luhur téh "goréng"; yén jalma sakuduna hirup harmonis jeung mahluk hirup séjénna; jeung yén alam kudu leupas tina pangaruh jalma.Ékologidina jihat ieu sok ogé disebuténvirontalisme.
Ékologi biasana dianggap salaku salah sahiji cabangbiologi, élmu umum nu ngulikmahluk hirup. Hal ieu bisa diulik dina sababaraha tingkatan, tiprotéinjeungasam nukléat(dinabiokimiajeungbiologi molekular),sél(dinabiologi sél), organisme (dinabotani,zoologi, jeung disiplin séjén nu sarupa), jeung pamungkas dina tingkatan populasi, komunitas, jeungékosistem— nu mangrupa subjék ékologi.
ku sabab fokusna nu panglegana dina kahirupan jeung dina hubunganana antara mahluk hirup jeunglingkunganna, ékologi ngamalir ka cabang élmu séjénna, kayaninggéologijeunggéografi,météorologi,pedologi,kimia, jeungfisika. ku sabab kitu, sakapeung ékologi sok disebut salaku élmuholistik.
Ékologi mindeng digambarkeun sabagé ulikanhubungansegitiga:
Ékologi mangrupa hiji élmu nu ambahanana ngahontal cabang-cabang husus nu loba, di antarana
Ékologi ogé boga ketak nu penting dina loba lapang interdisiplin:
Pamungkas, ékologi ogé dipangaruhan (jeung nginjeumkeun ngaranna ka) disiplin non-biologis séjénna kayaning
Artikel utama:Biosfir,Biodiversiti,Unified neutral theory of biodiversity
Pikeun ahli ékologi modérn, ékologi bisa diulik dina sababaraha tingkatan: tingkatpopulasi(individu nu saspésiés), tingkatbiocenose(atawa kumpulan spésiés), tingkatékosistem, jeung tingkatbiosfir.
Bumi, tina jihat ékologis, diwangun ku sababaraha rohangan:hidrosfir(atawa lapisan cai),litosfir(atawa lapisan taneuh lan batu), jeungatmosfir(atawa lapisan hawa).Biosfir, sakapeung digambarkeun mangrupa lapisan kaopat, mangrupa bagian planét tempat hirup kumbuh. mangrupa lapisan nu kacida ipisna, biosfir aya di antara 11000 méter ka jero jeung 15000 méter ka langit, najan lolobana kahirupan ayana di wewengkon antara -100 jeung +100 méter.
Kahirupan munggaran tumuwuh di hidrosfir, dinazona fotik. Organisme multisélular saterusna mucunghul turta ngeusizona béntik. Kahirupan terestrial tumuwuh ka dieunakeun, sanggeus ngawujudnalapisan ozonnu mayungan mahluk hirup tina cahyaUV. Tumuwuhna rupa-rupa spésiés terestrial diduga ngaronjat alatanbeulahnaatawa ngahijina buana. Biosfir jeung biodiversiti mangrupa ciri nu teu bisa dipisahkeun ti Bumi. Biosfir digambarkeun salaku lapisan kahirupan, sedengkeunbiodiversitisalaku kabinékaanana. Lapisan salaku wadahna, sedengkeun kabinékaan salaku eusina. Kabinékaan ieu diéksprésikeun kalawan babarengan dina tingkat ékologis (ékosistem), tingkat populasi (kabinékaan intraspésifik), jeung tingkat spésiés (kabinékaan spésifik).
Biosfir ngandung unsur nu jumlahna kalintang loba, kayaningkarbon,nitrogén, jeungoksigén. Unsur séjénna, kayaningfosfor,kalsium, jeungkalium, ogé penting pikeunkahirupan. Dina tingkat ékosistem jeung biosfir, aya prosés daur ulang sakabéh unsur-unsur ieu nu permanén, nu robah-robah antara wujud mineral jeung wujud organik.
While there is a slight input of géothermal energy, the bulk of the functioning of the ecosystem is primarily based on the input ofsolar energy. Plants convertlightinto into chemical energy by the process ofphotosynthesis, which créatesglucose(a simple sugar) and reléases freeoxygen. Glucose thus becomes the secondary energy source which drives the ecosystem. Some of this glucose is used directly by other organisms for energy. Other sugar molecules can be converted to other molecules such asamino acids. Plants use some of this sugar, concentrated innectarto entice pollinators to aid them in reproduction.(Honeybees concentrate the sugar still further as honey, which can be said to be "stored summer sunshine").
Cellular respirationis the process by which organisms (likemammals) bréakdown the glucose back to its constituents,caijeungkarbon dioksida, gaining back the stored energy the sun originally gave to the plants. The proportion of photosynthetic activity of plants to the respiration of other organisms determines the specific composition of the éarth's atmosphere, particularly its oxygen level.Global air currentsmix the atmosphere and maintain néarly the same balance in aréas of intense biological activity and aréas of slight biological activity.
Cai ogé disilihtukeurkeun antara hidrosfir, litosfir, atmosfir, jeung biosfir dinadaurnu teratur. Sagara mangrupa téngki raksasa, nu ngawadahan cai, mastikeun stabilitas panas jeung cuaca, ogé pindahna unsur-unsur kimia ku ayanaarus sagara.
For better understanding of how the biosphere works, and the dysfunctions related to human activity, American scientists carried out, undergreenhouses, a small-scale modél of the biosphere, calledBiosphere II.
Artikel utama:Ékosistem
Prinsip utama ékologi nyéta unggal mahluk hirup mibanda hubungan nu lumangsung tur sinambung jeung unggal unsur séjén nu nyusun lingkunganna. Hijiékosistembisa didefinisikeun salaku kaayaan naon baé nu mibanda karakter interaksi antara organisme jeung lingkunganana.
Ékosistem disusun ku dua éntitas: ayana kahirupan (disebutbiocenose) jeung lahan/média pikeun hirup kumbuhna (biotope). Jeroeun ékosistem, spésiés-spésiés silih hubungkeun jeung silih gumantung hiji jeung nu séjénna dinaranté dahareun, parobahanénérgi, sarta parobahanmatterantara maranéhna jeung lingkunganana.
Konsép ngeunaan hiji ékosistem bisa dilarapkeun ka unit-unit nu ukuranana baréda, hijibalong, hiji lapang, atawa sapotong tunggul kai. Unit nu ukuranana leutik disebut hijimikroékosistem. Pikeun conto, hiji ékosistem basa mangrupa hiji batu jeung sagala kahirupan di handapeunana. Hijimésoékosistembisa mangrupa hijileuweung, jeung hijimakroékosistemsakuliahecoregion, kaasupgawirna.
Patalékan utama nalika ngulik hiji ékosistem di antarana,
Ékosistem mindeng digolongkeun dumasar biotop nu patali. Ékosistem di handap ieu bisa dihartikeun:
Golongan-golongan séjénna bisa dijieun dumasar komunitasna (misalnaékosistem manusa).
Artikel utama:faktor ékologis,siklus géobiokimia,homeostasis,dinamika populasi
Biotop mangrupa wewengkon nu lingkunganana saragam, ditunjukkeun ku sakabéh ukuran géologis, géografis, jeung klimatologis nu disebutfaktor ékologis abiotik:
Biosénosa, atawa komunitas, mangrupa kumpulan populasi tatangkalan, sato, jeung mikro-organisme. Tiappopulasimangrupa jumlah hasil kawin- baranahan individu-individu nusaspésiésdi hiji wewengkon dina hiji waktu. Nalika hiji populasi jumlah anggotana teu nyukupan, spésiésna kaancam punah, boh alatanunderpopulationatawa alatankawin saturunan. Hiji populasi bisa ngurangan ku sababaraha sabab, misalna, alatan leungit habitatna (karuksakan leuweung) atawa alatan loba teuing prédator (saperti diboro).
Biosenosa dicirikeun ku dua tipefaktor ékologis biotik: hubungan intra- jeung inter-spésifik.
Hubungan intraspésifikmangrupa hubungan nu dingawujud antarindividu nu saspésiés nu ngabentuk hiji populasi: mangrupa hubunganko-operasiatawakompetisi, kalawan ayana babagi wewengkon kakawasaan, jeung kadang organisasi dina susunan hirarkis.
Hubungan interspésifik, nyéta hubungan nu aya antara spésis nu hiji jeung nu séjénna, loba pisan, jeung biasana digambarkeun nurutkeun pangaruh kauntungan, karugian, atawa nétral (misalnasimbiosis(hubungan ++) atawakompetisi(hubungan --)). Hubungan nu pangsignifikanana mah nyéta hubunganprédasi(ngahakan atawa dihakan), nu ngajurung kana konsép dasar dina ékologiranté dahareun(misalna, jukut dihakan ku hérbivora, nu dihakan ku karnivora, nu ogé dihakan ku karnivora nu leuwih badag).Ecological nichemangrupa wewengkon nu dipaké babarengan ku dua spésiés nu nempatan wewengkon sarta rupadietnu sarua.
The existing interactions between the various living beings go along with a permanent mixing of mineral and organic substances, absorbed by organisms for their growth, their maintenance and their reproduction, to be finally rejected as waste.  These permanent recyclings of the elements (in particularcarbon,oxygenandnitrogen) as well as thewaterare calledbiogeochemical cycles.  They guarantee a durable stability of the biosphere  (at léast when human influence andextreme weatherphenomena are left aside).  This self-regulation, supported by negativefeedbackcontrols, ensures the perenniality of the ecosystems. It is showed by the very stable concentrations of most elements of éach compartment.  This is referred to ashomeostasis.  The ecosystem also tends to evolve to a state of idéal balance, réached after asuccessionof events, theclimax(for example a pond can become apeat bog).
Main articles:Biome,ecozone
Ecosystems are not isolated from éach other, but are interrelated.  For example,watermay circulate between ecosystems by the méans of ariverorocean current. Water itself, as a liquid medium, even defines ecosystems.  Some species, such assalmonor freshwatereelsmove between marine systems and fresh-water systems.  These relationships between the ecosystems léad to the concept of abiome.
Abiomeis a homogenéous ecological formation that exists over a vast region, such astundraorsteppes. Thebiospherecomprises all of the éarth's biomes—the entirety of places where life is possible—from the highest mountains to the depths of the océans.
Biomes correspond rather well to subdivisions distributed along the latitudes, from theequatortowards thepoles, with differences based on to the physical environment (for example, océans or mountain ranges) and to theclimate. Their variation is generally related to the distribution of species according to their ability to tolerate temperature and/or dryness.  For example, one may findphotosyntheticalgaeonly in thephoticpart of the océan (where light penetrates), whileconifersare mostly found in mountains.
Though this is a simplification of more complicated scheme,latitudeandaltitudeapproximate a good representation of the distribution ofbiodiversitywithin the biosphere.  Very generally, the richness of biodiversity (as well for animal than plant species) is decréasing most rapidly néar theequator(as inBrazil) and less rapidly as one approaches thepoles.
The biosphere may also be divided intoecozone, which are very well defined today and primarily follow the continental borders.  The ecozones are themselves divided intoecoregions, though there is not agreement on their limits.
Dina hiji ékosistem, patali antarspésiés sacara umum dihubungkeun kanadahareunjeung peranna dinaranté dahareun. Aya tilu kategori organisme:
Hubungan-hubungan ieu ngawujud urutan, di mana unggal individu ngahakan nu saméméhna sarta dihakan ku nu saanggeusna, dina nu disebutranté dahareunatawa [[jaringan dahareun. In a food network, there will be fewer organisms at éach level as one follows the links of the network up the chain.
These concepts léad to the idéa ofbiomass(the total living matter in a given place), ofprimary productivity(the incréase in the mass of plants during a given time) and ofsecondary productivity(the living matter produced by consumers and the decomposers in a given time).
These two last idéas are key, since they maké it possible to evaluate theload capacity—the number of organisms which can be supported by a given ecosystem.  In any food network, the energy contained in the level of the producers is not completely transferred to the consumers.  Thus, from an energy point of view, it is more efficient for humans to be primary consumers (to get nourishment from grains and vegetables) than as secondary consumers (from herbivores such as beef and véal), and more still than as a tertiary consumer (from éating carnivores).
The productivity of ecosystems is sometimes estimated by comparing three types of land-based ecosystems and the total of aquatic ecosystems:
Humanity's actions over the last few centuries have seriously reduced the amount of the éarth covered by forests (deforestation), and have incréased agro-ecosystems (agriculture). In recent decades, an incréase in the aréas occupied by extreme ecosystems has occurred (desertification).
Sacara umum,krisis ékologisnyéta naon rupa kajadian nu ngarobahlingkunganhirup hiji spésiés atawa populasi antukna ngabahyakeun kasalametanana.
Ieu bisa mangrupa kualitas lingkungan nu nurun dibandingkeun jeung pangabutuh spésiés alatan parobahanfaktor ékologisabiotik (pikeun conto, naékna suhu, hujan nu beuki jarang).It may be that the environment becomes unfavourable for the survival of a species (or a population) due to an incréase pressure ofpredation(for example overfishing).Lastly, it may be that the situation becomes unfavourable to the quality of life of the species (or the population) due to raise in the number of individuals (overpopulation).
Ecological crises may be more or less brutal (occurring between a few months to a few million yéars).  They can also be of natural or anthropic origin.  They may relate to one unique species or on the contrary, to a high number of species (see the article onExtinction event).
Lastly, an ecological crisis may be local (as anoil spill) or global (a rise in the séa level related toglobal warming).
According to its degree of endemism, a local crisis will have more or less significant consequences, from the déath of many individuals to the total extinction of a species.  Whatever its origin, disappéarance of one or several species often will involve a rupture in thefood chain, further impacting the survival of other species.
In the case of a global crisis, the consequences can be much more significant; some extinction events showed the disappéarance of more than 90% of existing species at that time.  However, it should be noted that the disappéarance of certain species, such as the dinosaurs, by freeing an ecological niche, allowed the development and the diversification of the mammals.  An ecological crisis thus paradoxically favored biodiversity.
Sometimes, an ecological crisis can be a specific and reversible phenomenon at the ecosystem scale.  But more generally, the crises impact will last.  Indeed, it rather is a connected series of events, that occur till a final point.  From this stage, no return to the previous stable state is possible, and a new stable state will be set up gradually (seehomeorhesy).
Lastly, if an ecological crisis can cause extinction, it can also more simply reduce the quality of life of the remaining individuals.  Thus, even if the diversity of the human population is sometimes considered thréatened (see in particularindigenous people), few péople envision human disappéarance at short span.  However,epidemic diseases,famines, impact on héalth of reduction ofair quality,food crises, reduction of living space, accumulation of toxic or non degradable wastes, thréats onkeystone species(gréat apes, panda, whales) are also factors influencing thewell-beingof péople.
During the past decades, it was observed an incréasing responsibility  of human in some ecological crises.  Due to his technological acquisitions and to a strong incréase in population, man is the only species whose activity has a major influence on his environment of life.
Some usually quoted examples as ecological crises are
salah sahijiahli ékologimunggaran jigana mahAristotlenu boga pangaresep kana rupa-rupa spésiés sato. Anjeunna dituturkeun ku loba naturalis kayaningBuffonjeungCarolus Linnaeus, nu damelanana sok dianggap salaku asal-usul ékologi modérn.
Salila abad ka-18 nepi ka munggaran abad ka-19, kakuatan maritim raya kayaning Prancis jeung Jérman, medalkeun loba ékspédisi éksplorasi dunya pikeun ngembangkeunhubungan dagang maritimjeung nagara-nagara séjén, sarta pikeun manggihan sumberdaya alam anyar, as well as to catalog them.  At the beginning of the18th century, about twenty thousand plant species were known, versus forty thousand at the beginning of the19th century, and almost 400,000 today.
These expeditions were joined by many scientists, includingbotanists, such as the German explorerAlexander von Humboldt.  Humboldt is often considered the true father of ecology.  He was the first to take on the study of the relationship between organisms and theirenvironment.  He exposed the existing relationships between observed plant species andclimate, and described vegetation zones usinglatitudeandaltitude, a discipline now known asgeobotany.
In1804, for example, he reported an impressive number of species, particularly plants, for which he sought to explain their géographic distribution with respect togeologicaldata.  One of Humboldt's famous works was "Idea for a Plant Geography" (1805).
Other important botanists includeAimé BonplandandEugenius Warming.
Deukeut ka taun1850aya nu narabas dina widang ieu ku medalna karyaCharles DarwinThe Origin of Species: Ecology passed from a repetitive, mechanical modél to a biological, organic, and henceevolutionarymodél.
Alfred Russel Wallace, nu leuwih heubeul sarta saingan Darwin, munggaran ngajukeun "géografi" spésiés sasatoan. Sababaraha ahli harita wanoh yén spésiés teu mandiri ti nu séjén, sarta digolongkeun kana spésiés tangkal, sato, sarta komunitas mahluk hirup atawabiocenose. Istilah ieu munggaran dikedalkeun taun1877kuKarl Möbius.
Dina abad ka-19, ékologi ngembang ku ayana papanggihan widangkimiakuLavoisierjeungde Saussure, utamana ngeunaandaur nitrogén. Sanggeus nengetan bukti yén kahirupan tumuwuhna ukur dina wates-wates rohangan nu ngawujudatmosfir,hidrosfir, jeunglitosfir, Ahli géologi AustriaEduard Suessngajukeun istilahbiosfirtaun1875. Suess ngajukeun ngaran biosfir pikeun kaayaan nu ngadukung kahirupan, kayaning nu kapanggih diBumi, nyaétaflora,fauna,mineral,daur zat, jeung sajabana.
Dina taun1920anVladimir I. Vernadsky, ahli géologi Rusia nu pindah ka Prancis, ngajéntrékeun pamanggih ngeunaan biosfir dina karyana "The biosphere" (1926), sarta ngagambarkeun prinsip-prinsip pondaméndaur biogéokimiawi. Mangka anjeunna ngartikeun ulang biosfir salaku jumlah sakabéhékosistem.
Karuksakan ékologis munggaran kabéjakeun dinaabad ka-18, ku baranahanana koloni-koloni nu ngakibatkeundéforestasi. Mimitiabad ka-19, ku ayanarévolusi industri, kamelang kana karuksakanlingkunganalatan kagiatan manusa beuki ningkat. Istilahecologistgeus dipaké ti panungtunganabad ka-19.
Sapanjangabad ka-19, géografi botanis jeung zoogéografi ngagabung jadi basisbiogéografi. Élmu ieu, nu ngurus habitat spésiés, nyiar jawaban pikeun ayana spésiés tinangtu di wewengkon nu tinangtu ogé.
Dina taun1935,Arthur Tansley,ahli ékologiInggris, nyiptakeun istilahékosistem, nyaéta sistem interaktif nu ngawujud antarabiocenose(kumpulan mahluk hirup) jeungbiotopna, lingkungan tempat maranéhna hirup. Mangka ékologi jadi élmu ngeunaan ékosistem.
Ékologi manusadimimitian dina taun1920an, ku ayana ulikan ngeunaan parobahansuksési vegetasidi kotaChicago. Saterusna jadi widang ulikan nu béda dina taun1970an. Ieu nyirikeun munggaran diakuna manusa, nu geus ngeusi satungtungbuanadunya, salaku hijifaktor ékologispenting. Manusa kalawan gedé-gedéan ngarobah lingkungan ku ngawangun habitat (utamanatata kota) ku kagiatan éksploitasi nu leket sapertiloggingjeungfishing, sarta pangaruh séjénagrikultur,pertambangan, jeungindustri. Di sagigireun ékologi jeung biologi, disiplin ieu ngawengku ogé élmu alam jeung sosial séjénna, kayaningantropologijeungétnologi,ékonomi,démografi,arsitékturjeungtata kota,tatambajeungpsikologi, sarta nu séjénna. Ngembangna ékologi manusa ngajurung  kana ngaronjatna peran élmu ékologis dina rarancang jeung ngokolaandayeuh.
Téori Gaia, nu diajukeun kuJames Lovelockdina karyanaThe Earth is Alive, geus ngalegaan sawangan yén Bumi kudu dihargaan salaku hiji makroorganisme tunggal nu hirup. Hususna dina pamadegan yénensemblesadaya organisme hirup geus ngalaman évolusi antukna mampuh ngatur lingkungan global — ku jalan mangaruhan paraméter fisik penting kayaning wangunan atmosfir, laju penguapan, kimia taneuh jeung sagara — nepi ka bisa mertahankeun kaayaan nu dipiharep pikeun mahluk hirup.
Sawangan ieu geus jadi totondén jaman harita, hususna persépsi nu beuki kuat satutasnaPerang Dunya kaduayén kagiatan manusa kayaningénergi nuklir,industrialisasi,polusi, jeung éksplorasisumberdaya alaminu kaleuleuwihi, katambah kupertumbuhan populasi éksponénsial, geus ngancam kaciptakeunanakatastropdina skala planet. Ku ayana kitu, majan kontoversial di kalangan élmuwan, hipotésis Gaia Lovelock geus dirontok ku lobapergerakan lingkungansalaku hiji sawangan nu ngagagas:indung-Bumina,Gaia, "jadi gering alatan manusa jeung kagiatanana".
Bener, ti abad ka-19 ékologi geus kalawan nyata relevan pikeunpergerakan sosial jeung filosofisnu patali jeung perlindunganlingkungan alami, kayaningkonservasionismjeungenvironmentalism. Ékologi kiwari geus jadi salah sahijijejer politispenting sarta sumberideologipikeun organisasi-organisasi politis penting samodélPartéy HéjojeungGreenpeace.
Ékologi geus jadi bagéan puseur dina politik Dunya ti taun1971,UNESCOmedalkeun program panalungtikan nu disebutMan and Biosphere, nu tujuanana pikeun ngaronjatkeun pangaweruh ngeunaan hubungan nu silih untungkeun antara manusa jeung alam. Sababaraha taun ti harita geus kaluar katangtuan ngeunaan konsépBiosphere Reserve.
Taun1972United Nations(Perserikatan Bangsa-bangsa, PBB) ngayakeun konferensi internasional lingjkungan manusa nu munggaran diStockholm, diluluguan kuRené Dubosjeung sababaraha ahli séjénna. Konferensi ieu pisan nu marajian frase "Mikir Global, Ketak Lokal" (Think Globally, Act Locally). The next major events in ecology were the development of the concept of biosphere and the appéarance of terms "biological diversity"—or now more commonlybiodiversity—in the1980s.  These terms were developed during theEarth SummitinRio de Janeiroin1992, where the concept of the biosphere was recognized by the major international organizations, and risks associated with reductions in biodiversity were publicly acknowledged.
Then, in1997, the dangers the biosphere was facing were recognized from an international point of view at theKyoto conference.  In particular, this conference highlighted the incréasing dangers of thegreenhouse effect—related to the incréasing concentration ofgreenhouse gasesin the atmosphere, léading toglobal changes in climate. InKyoto, most of the world's nations recognized the importance of looking at ecology from a global point of view, on a worldwide scale, and to take into account the impact of humans on the éarth's environment.
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