Herbaariumi kasutamine kliimamuutuse mõju uuringus
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Kuupäev
2022
Kättesaadavus
02.09.2022
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Globaalne õhutemperatuur on juba pikemat aega püsinud tõusuteel, kuid eelmisest
sajandist alates on soojenemine oluliselt kiirenenud. Kliimamuutus mõjutab organismide
fenoloogiat ehk sessoonset arengut ning sellest tulenevalt liikidevahelisi suhteid. Eriti
tundlik temperatuurimuutuse suhtes on õitsemine. Varasematest töödest selgub, et kliima
soojenemise tõttu on õitsemine viimase 100 aasta jooksul varasemaks muutunud. Antud
töö eesmärk on välja selgitada, kas Eest herbaarandmeid saab kliimamuutuste mõju
uurimiseks kasutada. Selleks analüüsiti tulikaliste õitsemisaja muutlikkust Eestis perioodil
1901-2020 Eesti teaduskogude herbaareksemplaride abil. Trendide selgitamisel kasutati
temperatuuriandmeid. Õitsemisaja muutuseid uuriti lineaarse regressioon- ja
dispersioonanalüüsiga programmis R. Statistilisel analüüsil leiti, et tulikaliste õitsemine
on uuritaval perioodil muutunud keskmiselt 16 päeva varasemaks, kusjuures viimastel
aastakümnetel on trend veelgi tugevnenud. Sealjuures, kevadel õitsevad liigid reageerisid
tõusvatele õhutemperatuuridele enam kui suvel õitsevad liigid. Kõige kiiremini on
õitsemine muutunud varasemaks Kagu- ja Kesk-Eestis ning tagasihoidlikum on trend
olnud Põhja-Eestis. Herbaarandmetega saadud tulemused ei erinenud oluliselt
varasematest, vaatlusandmete põhjal tehtud tööde tulemustest. Järelikult saab ka Eestis
kogutud herbaareksemplare kasutada kliima teemalistes uuringutes nagu mujal maailmas
on seda tehtud. Antud lõputöö tulemused osutavad vajadusele ning tähtsusele edaspidi
uurida kliima soojenemise tagajärgesid ka kõrgematele troofilistele tasemetele ning
liikidevahelistele suhetele. Lisaks saab uurida teisi kasvuetappe, näiteks viljumist, et
mõista kliimamuutuse mõju taimele kogu elu jooksul.
Global air temperature has continued to increase for a considerable time, but since the last century warming has accelerated significantly. Climate change is affecting the phenology -the timing of life history events- of organisms and, as a result, inter-species relations are being interfered with. Flowering is particularly sensitive to temperature changes. Previous work has shown that due to warming, flowering has become earlier in the last 100 years. The aim of this work is to determine whether herbarium data from Estonia can be used to study the effects of climate change. The flowering of species from the family Ranunculaceae was investigated on herbarium specimens collected within the territory of Estonia during the period 1901-2020. Temperature data was used to explain trends. Changes in flowering time were studied by linear regression and variance analysis with the program R. Statistical analysis showed that the flowering of Ranunculaceae has started on average 16 days earlier during the study period, whereas the trend has intensified in recent decades. In addition, spring-flowering species had a greater response to rising air temperatures than summer-flowering species. In south-eastern and central Estonia flowering has progressed more rapidly, while in North-Estonia the trend has been moderate. The results obtained with herbarium specimens did not differ substantially from the previous work based on observational data. Thus, the herbarium specimens collected in Estonia can also be used in climate research, as it has been done elsewhere in the world. Based on herbarium material, the effects of global warming on higher trophic levels and inter-species relationships can be assessed. Furthermore, other growth stages, such as fruiting, can be studied to understand the impact of climate change on a plant during its lifetime.
Global air temperature has continued to increase for a considerable time, but since the last century warming has accelerated significantly. Climate change is affecting the phenology -the timing of life history events- of organisms and, as a result, inter-species relations are being interfered with. Flowering is particularly sensitive to temperature changes. Previous work has shown that due to warming, flowering has become earlier in the last 100 years. The aim of this work is to determine whether herbarium data from Estonia can be used to study the effects of climate change. The flowering of species from the family Ranunculaceae was investigated on herbarium specimens collected within the territory of Estonia during the period 1901-2020. Temperature data was used to explain trends. Changes in flowering time were studied by linear regression and variance analysis with the program R. Statistical analysis showed that the flowering of Ranunculaceae has started on average 16 days earlier during the study period, whereas the trend has intensified in recent decades. In addition, spring-flowering species had a greater response to rising air temperatures than summer-flowering species. In south-eastern and central Estonia flowering has progressed more rapidly, while in North-Estonia the trend has been moderate. The results obtained with herbarium specimens did not differ substantially from the previous work based on observational data. Thus, the herbarium specimens collected in Estonia can also be used in climate research, as it has been done elsewhere in the world. Based on herbarium material, the effects of global warming on higher trophic levels and inter-species relationships can be assessed. Furthermore, other growth stages, such as fruiting, can be studied to understand the impact of climate change on a plant during its lifetime.
Kirjeldus
Bakalaureusetöö
Vee ja maismaa ökosüsteemide rakendusbioloogia õppekaval
Märksõnad
bakalaureusetööd, kliimamuutus, globaalne soojenemine, fenoloogia, herbaareksemplarid, Eesti