Browsing by Subject "conservation"
Now showing items 1-11 of 11
-
(2020)Conservation actions towards large carnivores have been successful in Europe, and the formerly lawfully persecuted species have started to reclaim their historical range. Coexistence with the predators is needed if their conservation should continue to succeed, as Europe does not host wilderness areas large enough to separate large carnivores from humans. As the importance of top-down regulation in ecosystems is recognized, the protection of these predators becomes essential. In Finland, all four large carnivore species, brown bear, grey wolf, Eurasian lynx and wolverine, have established populations, though their presence is not easily accepted by some. Large carnivores pose a threat to livestock and cause fear in the locals living in their territories. Wolf – hunting dog conflict is especially prominent in Finland south of reindeer husbandry area and the poaching of wolves hinders the population’s management. Attitudes towards large carnivores are often influenced by personal background, such as education level, ecological knowledge and respondent’s position in possible human – wildlife conflict. Residence can have an effect, as well, since conditions between living in urban or rural areas often differ. Hypothesis for this study are 1) attitudes towards large carnivores get worse while getting closer to protected areas, 2) attitudes towards large carnivores differ between eastern and western study areas, and 3) a higher education level increases positive attitudes towards large carnivores. The effect of ecological knowledge, prior experiences with large carnivores, age, sex and position in conflict was also explored. Study was conducted as a questionnaire, with face-to-face interviews and web survey distribution targeting two areas in Finland with large carnivore occupancy, one in the West and one in the East. A link between negatively perceived personal experiences and negative opinions towards large carnivores and their management was found. Living in the western area, where large carnivores have resided for a shorter time, predicted attitudes towards stricter management of the species. Third level education influenced attitudes positively. By understanding local attitudes towards large carnivores, it is possible to better understand the conflict between humans and predators, and so, find more likely solutions. Conservation actions where locals have been included, have been documented as successes. Regional differences in attitudes should be further studied and included in future decision making.
-
(2020)Suurpetojen suojeluun tähtäävät toimet ovat onnistuneet Euroopassa, ja nämä ennen vainotut lajit ovat alkaneet levittäytyä takaisin historiallisille levinneisyysalueilleen. Yhteiselon suurpetojen kanssa on onnistuttava, mikäli niiden suojelussa halutaan onnistua jatkossakin, sillä Euroopan erämaa-alueet eivät ole tarpeeksi suuria ihmisten ja suurpetojen erottamiseen. Ylhäältä alaspäin tapahtuvan ekosysteemisäätelyn tärkeyden ymmärtämisen jälkeen näiden petojen suojelusta on tullut elintärkeää. Suomessa kaikki neljä suurpetoa, ruskeakarhu, harmaasusi, euraasialainen ilves ja ahma, ovat vakiinnuttaneet populaationsa, mikä ei ole osalle ihmisistä helposti hyväksyttävä asia. Suurpedot uhkaavat koti- ja tuotantoeläimiä sekä aiheuttavat pelkoa niiden alueilla asuville. Susien ja metsästyskoirien välillä oleva konflikti on erityisen huomattava poronhoitoalueen eteläpuolisessa Suomessa ja susien laiton metsästys haittaakin lajin suojelua. Suurpetoihin kohdistuviin asenteisiin vaikuttaa usein henkilökohtainen tausta, kuten koulutustaso, tuntemus ekologiasta sekä asema mahdollisessa ihmisen ja luonnon välisessä konfliktissa. Asuinpaikalla voi myös olla merkitystä, sillä usein asumisen olosuhteet eroavat kaupunki-maalaisympäristön välillä. Tutkimuksen hypoteesit ovat 1) suurpetoasenteet huononevat lähestyttäessä suojelualueita, 2) suurpetoasenteet eroavat idän ja lännen välillä, ja 3) korkeampi koulutustaso lisää positiivista suhtautumista suurpetoihin. Myös ekologisen tiedon, edeltävien suurpetoihin liittyvien kokemusten, iän, sukupuolen ja konfliktiin liittyvät aseman vaikutusta selvitettiin. Tutkimus toteutettiin kyselynä hyödyntäen sekä haastatteluita että internetlomaketta kahdella suurpetojen elinalueella Suomessa, yhden alueen sijaitessa idässä ja toisen lännessä. Negatiivisesti koettujen henkilökohtaisten kokemusten ja negatiivisten mielipiteiden välillä havaittiin linkki käsiteltäessä mielipiteitä sekä suurpetoja että niiden kannanhoitoa kohtaan. Lännessä, missä suurpetoja on ollut läsnä vähemmän aikaa, oltiin todennäköisemmin tiukemman kannanhoidon puolella. Kolmannen asteen koulutus vaikutti asenteisiin positiivisesti. Suurpetoasenteisiin ei vaikuttanut etäisyys suojelualueista. Ymmärtämällä paikallisia suurpetoasenteita on mahdollista ymmärtää paremmin myös suurpetokonfliktia ja sitä kautta löytää mahdollisia ratkaisuja. Kun paikalliset on otettu luonnonsuojelutoimenpiteisiin mukaan, on niiden onnistuminen ollut todennäköisempää. Asenteiden alueellisia eroja tulisi tutkia lisää ja nämä tulokset täytyisi sisällyttää tulevaisuudessa päätöksentekoprosessiin.
-
(2020)Wildlife capture is an event in which a wild animal is caught by a human. Reasons for wildlife captures vary: marking, collaring with a tracking device, disease surveillance, translocations related to conservation or commercial purposes, treating injuries and taking samples for research are some examples. Objective information about movement patterns and numbers of animals is needed for population management. Increased interest in disease monitoring and understanding the complex relationship between wildlife, people, domestic animals and environment has lead to a need for interdisciplinary approach to health issues, also known as ‘One Health’. Gaining information from wildlife by capturing them has an important role in health research of all species. Wildlife capture is often a complex event that should be carefully planned. Multiple non-chemical methods for capturing are available, such as traps, net-guns, drop-nets, drive nets or driving a group of animals into a corral. Chemical immobilization is usually done by remote delivery using a dart that injects immobilizing drugs to the animal. A large variety of drugs and drug combinations are used for wildlife captures. The animal species and previous research, equipment used and procedures that are supposed to be done during the capture are some of the main factors determining the type and length of anaesthesia needed, and therefore the specific drug combination preferred. When talking about wildlife captures, two essential terms are usually involved: immobilisation and anaesthesia. Immobilized animal is uncapable to move or its movement is more or less restricted by physical restraint or immobilizing drugs. General anaesthesia is a drug-induced state characterized by anti-nociception, suppressed reflexes and loss of consciousness of the animal. Certain drugs can be used to create anxiolytic (calming), sedative (mental calming) or narcotic (opioid analgesics induced sedation) effects, and these may also create a smoother induction, maintenance or recovery from general anaesthesia. There are multiple capture-related challenges and risks for both animals and humans involved. In the field unexpected events, such as sudden weather changes, injuries, failures of equipment, drug complications or accidental exposures, abrupt physiological reactions or getting infected by a pathogen from another species, can occur. Prevention is often easier that dealing with an accident or medical condition that has already happened. This literature review aims to explain briefly why and how wildlife is captured, and gives a concise overview about some issues that need to be considered before a wildlife capture. In the end a short insight on Finnish large carnivore captures is presented with reflections to methods used in several other countries.
-
(Helsingin yliopistoUniversity of HelsinkiHelsingfors universitet, 2002)Madagascar is one of the megadiversity countries of the world and its highly endemic flora and fauna is under threat from a rapidly growing population. Over the past few years many conservation projects have combined development goals with conservation, thus supporting the conservation goal by attempting to ease human pressure on the protected area. The objective of this study is to investigate the views and opinions of local people with regard to Ranomafana National Park, Madagascar. This study examines the changes the park has brought to peoples’ lives, general attitudes towards the environment and conservation as well as opinions about the park management. The main information presented in this study was obtained from 121 interviews completed in six villages. Three of them are situated close to the park and they have received intentional development interventions from the authorities. Another three lie further away and have no official connections with the park. The study will investigate how distance and interventions affect peoples views and opinions. The information obtained represents independent opinions from a random sample of the resident population. All the schools of each village were visited and over 400 pupils responded to a questionnaire about the environment. In addition to this the NGO's, local authorities, health centres, churches and a family planning clinic, were consulted in order to gain a thorough picture of the communities views. People in the villages closest to the park have obtained employment through tourism and research. Other positive effects include assistance with new farming methods, the introduction of alternative livelihoods and environmental education. Villagers further away from the park mentioned the slowing down of environmental degradation as the major achievement of the park. The major negative effect is restrictions on usage of the natural resources people depend on. Adequate alternatives are not available and direct compensation for economic losses has not been offered. This study presents people’s suggestions on improving education, management of the park, livelihoods and environment. More efficient development projects that geographically reach further would help the park to achieve its development goals and through that the conservation objectives. The results of this study emphasise the importance of education, which increases people’s awareness of the environmental processes. This enables them to understand the consequences of human activities and gives them an awareness of the consequences of continuing unsustainable use of resources. Decreasing poverty near protected areas is also essential in order to reduce pressure on the environment. A third important issue is the slowing down of population growth. Successful combination of conservation and development requires constant reassessment and responses to changing situations. The survival of Madagascar’s rain forests is a global concern so responsibility and costs must be borne globally, too.
-
(2015)Suomesta tavataan kaksi majavalajia: alkuperäinen euroopanmajava (Castor fiber) ja vieraslaji amerikanmajava (Castor canadensis). Euroopanmajava metsästettiin sukupuuttoon 1800–luvulla ja viimeinen euroopanmajava ammuttiin tiettävästi Sallan Eniönjoesta vuonna 1868. Vuonna 1935 aloitettiin majavien uudelleenistutukset 17 Norjasta tuodulla euroopanmajavalla. Vuonna 1937 Suomen majavakantaa vahvistettiin seitsemällä Amerikasta tuodulla amerikanmajavalla. Tahallisesta vieraslajin tuomisesta ei kuitenkaan ollut kyse, vaan vasta vuonna 1973 todettiin Castor-suvun koostuvan kahdesta eri lajista. Alueilla, joille istutettiin molempia lajeja, on jäljellä ainoastaan amerikanmajava. Syyt ovat edelleen epäselviä. Molempien lajien kannat ovat edelleen keskittyneet alkuperäisten istutusalueiden läheisyyteen, ja amerikanmajavakanta on muutamia poikkeuksia lukuun ottamatta saanut kasvaa ilman euroopanmajavan kilpailun vaikutusta. Jos lajien elinympäristövaatimukset ovat samat, eivät lajit voi esiintyä rinnakkain. Näin ollen on tärkeää tuntea molempien lajien elinympäristön käyttö mahdollisemman tarkkaan aluekohtaisesti ja ennakoida, johtaako majavalajien kohtaaminen kahden lajin rauhaisaan yhteiseloon vai mahdollisesti euroopanmajavan häviämiseen läntisestä Suomesta. Tutkimuksen tarkoituksena oli vertailla lajien elinympäristön vaatimuksia ja sitä kautta tuoda lisätietoa euroopanmajavan suojeluun. Tutkimusalueeksi valikoitui keskinen Pirkanmaan alue, missä lajien välinen etäisyys on ainoastaan 11 kilometriä linnuntietä. Aineisto koostuu vuoden 2013 Luonnonvarakeskuksen koordinoimista valtakunnallisten majavalaskentojen pesätiedoista sekä erilaisista paikkatietoaineistoista. Elinympäristönkäytön mallin muuttujat on tuotettu CORINE Land Cover 2012 (CLC2012), vuoden 2011 Valtakunnallisen Metsien Inventoinnin (VMI) ja Maanmittauslaitoksen maastotietokannan digitaalisiin paikkatietoaineistojen avulla. Alueelle luotiin 60 satunnaispistettä, jotka kuvaavat tarjolla olevaa elinympäristöä. Lajien elinympäristöjen käyttöä analysoitiin kahden logistisen regressioanalyysimallin avulla, joista ensimmäisessä tarkastellaan ydinaluetta (50m) ja toisessa elinpiiriä (1km). Analyyseissä verrattiin lajeja keskenään sekä satunnaispisteisiin. Ennen regressioanalyysejä tarkasteltiin muuttujien kolineaarisuutta Variance Inflation Factor:in (VIF) avulla, jonka jälkeen tarkasteltiin aineiston yhteensopivuuttaa mallin kanssa Akaiken informaatiokriteerin (AIC) avulla. Pienin AIC ilmaisee parhaan mallin korkeimman selitysasteen ja mallin yksinkertaisuuden (parsimonisuuden) kompromissina. Ydinalueella ei havaittu merkitseviä eroja elinympäristön vaatimuksissa lajien välillä. Majavien elinympäristönkäyttö ei kuitenkaan ollut satunnaista. Kuusen tilavuudella oli positiivinen vaikutus euroopanmajavan esiintymiseen ja lehtipuiden tilavuudella oli positiivinen vaikutus amerikanmajavan esiintymiseen verrattuna tarjolla olevaan ympäristöön. Elinpiirianalyyseissä lajien välillä havaittiin merkitseviä eroja, joissa euroopanmajava esiintyi alueilla, missä kuusen tilavuus ja sekametsän osuus oli suurempi verrattuna amerikanmajavan elinpiiriin. Kasvavalla kuusen tilavuudella, sekametsän osuudella sekä vesistöjen määrällä oli positiivinen vaikutus euroopanmajavan esiintymiseen ja rakennetuilla alueilla negatiivinen vaikutus euroopanmajavan esiintymiseen verrattaessa tarjolla olevaan ympäristöön. Amerikanmajavan elinympäristön käyttö ei poikennut satunnaisesta. Tulokset saattavat heijastaa rantavyöhykkeen metsäsukkession eri vaiheita, mutta on huomattava, että lajien välillä oli merkittäviä eroja. Elinympäristön muuttujat selittivät huomattavasti enemmän euroopanmajavan esiintymistä alueella verrattuna amerikanmajavaan. Toisin sanoen euroopanmajavan elinympäristön vaatimukset ovat spesifimmät/tarkemmat/ominaisemmat. Tulosten avulla on mahdollista ennustaa niin amerikanmajavan leviämistä alueella kuin hyödyntää tietoja euroopanmajavalle tärkeiden elinympäristöjen suojelussa.
-
(2019)Not much attention is paid on the conservation of invertebrates despite their importance to the ecosystems in general and their benefits and ecosystem services to us, humans. This study is part of a project aiming to start the Sampled Red List Index (SRLI) for spiders. The IUCN Red List Index (RLI) is used for measuring the overall extinction risk of groups of species and the sampled approach is a way to evaluate the trajectory towards extinction of megadiverse groups without the need to assess every species of the whole group of interest. A random sample of 200 spider species were selected from the global checklist and assessed according to IUCN Red List Categories and Criteria. Given the availability of data, I was able to calculate the extent of occurrence and area of occupancy for 80 species, of which 70 species had an EOO above 20000 km² and 75 species an AOO above 2000 km², the thresholds below which species can be considered threatened. The trends in EOO and AOO were assumed to be stable for most species (49 species) given the inexistence of monitoring data for any taxon. Evidence of decline was found for only 10 species, usually inferred from habitat loss. Habitat data was collected for 118 species. The most common habitat type was forest (73 species), followed by grasslands (24 species) and artificial habitats (22 species). For 44 species the habitat trend was inferred to be stable, only declining, according to available knowledge, for 14 species and increasing for one species. For the remaining 141 species the habitat trend could not be inferred and was thus assumed to be unknown. The most commonly mentioned threat types were agriculture (11 species), fires (7 species) and logging (6 species). For 39 species there were no known threats and for the rest of the 132 species the threats were unknown. Conservation actions in place were observed for 104 species, most commonly site and area protection (100 species) and resource and habitat protection (88 species). Conservation actions such as education and awareness (8 species), resource and habitat protection (7 species) and site and area management (6 species) were to take into consideration. All the 200 species were estimated to be in need of further basic research especially on threats (143 species and distribution (140 species), but also on life history and ecology (135 species). Due to several knowledge shortfalls, including the Wallacean (distribution of species), Prestonian (population trends) and Hutchinsonian (response to environmental change), no threat category could be reached for the vast majority of the species. The results show that an IUCN category could be reached for only 59 species, of which 55 were assessed as Least Concern and a threatened category was reached for only 4 species (t as Critically Endangered and one as Vulnerable). The baseline SRLI at this first point in time was 0.95 (in a 0-1 scale, where 0 means all species are extinct and 1 for all species are Least Concern). We hypothesize however that among the 141 Data Deficient species there should be a higher proportion of threatened species than among the 59 evaluated. This would be due to two reasons. First, the scarcity of information on many species might in part be due to their rarity. Second, widespread species were often the only for which an assessment could be reached, creating a bias in the dataset towards a large base SRLI value. The strategy currently imposed by IUCN is therefore clearly inadequate for taxa with scarce information, which represent the vast majority of species. I propose the future use of a different, non-random, approach to the selection of species in the SRLI and its adoption for other taxa which represent in fact most extant and threatened species.
-
(2020)High Nature Value (HNV) farming systems hold significant natural values but have decreased drastically during the process of agricultural modernization. Biodiversity in Europe is dependent on these extensively farmed areas because they maintain habitats for many endangered species; e.g. 30% of Europe's butterfly species have declining populations and most live in natural and semi-natural habitats. European common agricultural policy (CAP) favour conventional agriculture, leading HNV agriculture in a foul position. HNV areas are often abandoned or replaced with intensive farming practices. Participatory agricultural innovation processes offer solutions to the distress of HNV farmlands. In these processes different actors – such as farmers, entrepreneurs, advisors, NGO and municipality representatives – are brought together to find localized solutions to the challenges of the area. HNV-Link project was active during years 2016-2019 identifying, developing and improving innovations in ten European HNV farming areas. In this thesis I examine the success of innovations in seven Learning Areas (LA) in terms of socio-economic viability, environmental conservation and cultural region. The data in this thesis is both quantitative and qualitative. I use mixed methods- approach where the statistical analysis and qualitative content analysis support each other. I carried out a survey for the LA coordinators where they responded how was the impact of the innovations to social, economic and environmental wellbeing. I complement the survey with data gathered by the project in 2016-2017. I conduct a qualitative content analysis to innovation fiches using Atlas.ti programme and a statistical analysis with IMB SPSS statistics programme with non-parametric tests. I compare the relation of socio-economic and environmental impact of the innovations, explicit aim of HNV conservation, recognition of environmental topics in the fiches and cultural region. Innovations were successful both socio-economically and environmentally. There was a possible synergy between economic and environmental impacts, which indicates economic viability of the LA’s improving HNV conservation. Innovations with explicit HNV conservation objective had more positive environmental impact than the ones without. Innovations with high recognition of environmental themes in fiches had slightly more positive environmental impact, but the difference was so weak that they fail to express the environmental outcomes reported in the survey. Congruent patterns didn’t occur inside cultural regions which might be due to the similarities of the areas or small sample size. The results display the inherent unpredictability of innovation processes, and the importance of holistic understanding and long-term monitoring of them.
-
(2020)Luonnonarvoiltaan merkittävät High Nature Value (HNV) maatalousalueet ovat vähentyneet maailmanlaajuisesti maatalouden modernisaation myötä. Luonnon monimuotoisuus on riippuvaista näistä alueista, sillä ne ylläpitävät habitaatteja lukuisille uhanalaisille lajeille. Esim. 30% Euroopan perhoslajien populaatioista on laskussa, ja suurin osa niistä elää HNV tai vastaavilla maatalousalueilla. EU:n maatalouspolitiikka suosii perinteistä, intensiivistä maataloutta, jonka vuoksi laaja-alainen HNV maatalous ei pärjää kilpailussa sen kanssa. Alhaisen tuottavuuden ja haastavien olosuhteiden takia HNV maatalousmaita jää hylätyksi, tai HNV järjestelmät korvataan intensiivisillä menetelmillä. Osallistavat maataloudelliset innovaatioprosessit tarjoavat ratkaisuja HNV maatalousalueiden ahdinkoon. Näissä prosesseissa tuodaan yhteen eri toimijoita – maanviljelijöitä, yrittäjiä, kansalaisjärjestöjen, kuntien ja valtioiden edustajia – etsimään paikallisesti perusteltuja ratkaisuja alueiden ongelmiin. Vuosina 2016-2019 toiminut HNV-Link projekti identifioi, kehitti ja edisti innovaatioita kymmenellä Eurooppalaisella HNV alueella. Tässä tutkielmassa tarkastelen projektin seitsemän toiminta-alueen innovaatioiden menestystä sosiaalis-taloudellisen elinvoimaisuuden sekä ympäristön hyvinvoinnin kannalta. Aineistoni on sekä määrällistä että laadullista. Käytän mixed-methods lähestymistapaa, jossa tilastollinen analyysi ja laadullinen sisältöanalyysi tukevat toisiaan. Tein kyselyn toiminta-alueiden koordinaattoreille, jossa he vastasivat millainen vaikutus innovaatioilla on ollut alueen sosiaaliseen, taloudelliseen ja ympäristön hyvinvointiin. Täydennän kyselyä projektin 2016-2017 keräämällä aineistolla. Suoritan laadullisen sisältöanalyysin projektin keräämille innovaatioiden kuvauksille Atlas.ti ohjelmalla ja tilastollisen analyysin IMB SPSS tilasto-ohjelmalla ei-parametrisin menetelmin. Vertailin innovaatioiden sosiaalis-taloudellisten ja ympäristönsuojelullisten vaikutusten, HNV suojelun ensisijaisen tavoitteen, innovaatiokuvausten ympäristönsuojelullisten aiheiden tunnistamisen sekä kulttuurillisten alueiden suhdetta. Innovaatiot olivat menestyksekkäitä niin sosiaalis-taloudellisesi kuin ympäristölle. Taloudellisen ja ympäristöllisen menestyksen välillä oli mahdollinen synergia, mikä viittaa siihen, että taloudellinen menestys alueilla edistää HNV piirteiden säilymistä alueella. Innovaatioilla, joiden erityinen tavoite oli HNV suojelu, oli positiivisempi vaikutus ympäristölle kuin niillä, joilla tavoite ei ollut ensisijainen. Innovaatioiden kuvauksissa, joissa ympäristönsuojelulliset teemat tulivat eniten esille, oli hieman positiivisempi vaikutus ympäristöön. Ero oli kuitenkin niin heikko, että kokonaisuudessaan niissä ei ole onnistuttu kommunikoimaan koordinaattoreiden raportoimia seurauksia ympäristölle. Kulttuurillisten alueiden sisällä ei ilmennyt yhteneviä kaavoja, joka voi johtua alueiden samankaltaisuudesta tai pienestä otoksesta. Tulokset korostavat innovaatioiden ennalta arvaamatonta luonnetta, sekä prosessien holistisen ymmärryksen sekä pitkäaikaisen seurannan tärkeyttä.
-
(2022)Remote sensing brings new potential to complement environmental sampling and measuring traditionally conducted in the field. Satellite images can bring spatial coverages and accurately repeated time-series data collection to a whole new level. While developing methos for doing ecological assessment from space in situ sampling is still in key role. Satellite images of relatively coarser pixel size where individual plants or trees are not possible to separate usually utilize vegetation indices as proxies for environmental qualities and measures. One of the most extensively used and studied vegetation index is Natural Difference Vegetation Index (NDVI). It is calculated as normalized ratio between red light and near-infra-red radiation with formula: NDVI=NIR- RED/NIR+RED. Index functions as a measure for plant productivity, that has also been linked to species-level diversity. In this thesis MODIS NDVI (MOD13Q1, 250 m x 250 m resolution) and selected additional variables were examined through their predictive power for explaining variation in tree species richness in six different types of moist tropical evergreen forests in the province of West Kalimantan, on the island Borneo in Indonesia. Simple and multiple regression models were built and tested with main focus on 20- year mean-NDVI. Additional variables used were aboveground carbon, elevation stem count, tree height and DBH. Additional variables were examined initially on individual basis and subsequently potential variables were then combined with NDVI. Results indicate statistically significant, but not very strong predictable power for NDVI (R2=0.25, p-value=2.11e-07). Elevation and number of stems outperformed NDVI in regression analyses (R2=0.64, p-value=2.2e-16 and R2=0.36, p-value=4.5e-11, respectively). Aboveground biomass carbon explained 19% of the variation in tree species richness (p-value=6.136e-06) and thus was the worst predictor selected for multiple regression models. Tree height (R2=0.062, p-value=0.0137) and DBH (R2=0.003, p-value=0.6101) did not show any potential in predicting tree species richness. Best variable combination was NDVI, elevation and stem count (R2=0.71, p-value=2.2e-16). Second best was NDVI, elevation and aboveground biomass carbon (R2=0.642, p-value=2.2e-16), which did not promote for biomass carbon as a potential predictor as model including only NDVI and elevation resulted nearly identically (R2=0.639, p-value=2.2e-16). Model including NDVI and stem count explained 54% of the variation in tree species richness (p-value=2.2e-16) suggesting elevation and stem count being potential variables combined with NDVI for this type of analysis. Problems with MODIS NDVI are mostly linked to the relatively coarse spectral scale which seems to be too coarse for predicting tree species richness. Spectral scale also caused spatial mismatch with field plots as being significantly of different sizes. Applicability in other areas is also limited due to the narrow ecosystem spectrum covered as only tropical evergreen forests were included in this study. For future research higher resolution satellite data is a relevant update. In terms methodology, alternative approach known as Spectral Variability Hypothesis (SVH), which takes into account heterogeneity in spectral reflectance, seems more appropriate method for relating spectral signals to tree species richness.
-
(2022)Remote sensing brings new potential to complement environmental sampling and measuring traditionally conducted in the field. Satellite images can bring spatial coverages and accurately repeated time-series data collection to a whole new level. While developing methos for doing ecological assessment from space in situ sampling is still in key role. Satellite images of relatively coarser pixel size where individual plants or trees are not possible to separate usually utilize vegetation indices as proxies for environmental qualities and measures. One of the most extensively used and studied vegetation index is Natural Difference Vegetation Index (NDVI). It is calculated as normalized ratio between red light and near-infra-red radiation with formula: NDVI=NIR- RED/NIR+RED. Index functions as a measure for plant productivity, that has also been linked to species-level diversity. In this thesis MODIS NDVI (MOD13Q1, 250 m x 250 m resolution) and selected additional variables were examined through their predictive power for explaining variation in tree species richness in six different types of moist tropical evergreen forests in the province of West Kalimantan, on the island Borneo in Indonesia. Simple and multiple regression models were built and tested with main focus on 20- year mean-NDVI. Additional variables used were aboveground carbon, elevation stem count, tree height and DBH. Additional variables were examined initially on individual basis and subsequently potential variables were then combined with NDVI. Results indicate statistically significant, but not very strong predictable power for NDVI (R2=0.25, p-value=2.11e-07). Elevation and number of stems outperformed NDVI in regression analyses (R2=0.64, p-value=2.2e-16 and R2=0.36, p-value=4.5e-11, respectively). Aboveground biomass carbon explained 19% of the variation in tree species richness (p-value=6.136e-06) and thus was the worst predictor selected for multiple regression models. Tree height (R2=0.062, p-value=0.0137) and DBH (R2=0.003, p-value=0.6101) did not show any potential in predicting tree species richness. Best variable combination was NDVI, elevation and stem count (R2=0.71, p-value=2.2e-16). Second best was NDVI, elevation and aboveground biomass carbon (R2=0.642, p-value=2.2e-16), which did not promote for biomass carbon as a potential predictor as model including only NDVI and elevation resulted nearly identically (R2=0.639, p-value=2.2e-16). Model including NDVI and stem count explained 54% of the variation in tree species richness (p-value=2.2e-16) suggesting elevation and stem count being potential variables combined with NDVI for this type of analysis. Problems with MODIS NDVI are mostly linked to the relatively coarse spectral scale which seems to be too coarse for predicting tree species richness. Spectral scale also caused spatial mismatch with field plots as being significantly of different sizes. Applicability in other areas is also limited due to the narrow ecosystem spectrum covered as only tropical evergreen forests were included in this study. For future research higher resolution satellite data is a relevant update. In terms methodology, alternative approach known as Spectral Variability Hypothesis (SVH), which takes into account heterogeneity in spectral reflectance, seems more appropriate method for relating spectral signals to tree species richness.
-
(2013)Lepidurus arcticus (Pallas, 1793) is a keystone species in High Arctic ponds, which are exposed to a wide range of environmental stressors. This thesis provides information on the ecology of this little studied species by paying particular focus on the sensitivity of L. arcticus to acidification and climate change. Respiration, reproduction, olfaction, morphology, salinity and pH tolerance of the species were studied in the laboratory and several environmental parameters were measured in its natural habitats in Arctic ponds. Current global circulation models predict 2–2.4 °C increase in summer temperatures on Spitsbergen, Svalbard, Norway. The L. arcticus respiration activity was tested at different temperatures (3.5, 10, 16.5, 20, 25 and 30 °C). The results show that L. arcticus is clearly adapted to live in cold water and have a temperature optimum at +10 °C. This species should be considered as stenothermal, because it seems to be able to live only within a narrow temperature range. L. arcticus populations seem to have the capacity to respond to the ongoing climate change on Spitsbergen. Changes can be seen in the species' reproductive capacity and in the individuals' body size when comparing results with previous studies on Spitsbergen and in other Arctic areas. Effective reproduction capacity was a unique feature of the L. arcticus populations on Spitsbergen. L. arcticus females reached sexual maturity at a smaller body size and sexual dimorphism appeared in smaller animals on Spitsbergen than anywhere else in the subarctic or Arctic regions. L. arcticus females were able to carry more eggs (up to 12 eggs per female) than has been observed in previous studies. Another interesting feature of L. arcticus on Spitsbergen was their potential to grow large, up to 39.4 mm in total length. Also cannibalistic behaviour seemed to be common on Spitsbergen L. arcticus populations. The existence of different colour morphs and the population-level differences in morphology of L. arcticus were unknown, but fascinating characteristic of this species. Spitsbergen populations consisted of two major (i.e. monochrome and marbled) and several combined colour morphs. Third interesting finding was a new disease for science which activated when the water temperature rose. I named this disease to Red Carapace Disease (RCD). This High Arctic crustacean lives in ponds between the Arctic Ocean and glaciers, where the marine environment has a strong impact on the terrestrial and freshwater ecosystems. The tolerance of L. arcticius to increased water salinity was determined by a LC50 -test. No mortality occurred during the 23 day exposure at low 1–2 ‰ water salinity. A slight increase in water salinity (to 1 ‰) speeded up the L. arcticus shell replacement. The observations from natural populations supported the hypothesis that the size of the animals increases considerably in low 1.5 ‰ salt concentrations. Thus, a small increase in water salinity seems to have a positive impact on the growth of this short-lived species. Acidification has been a big problem for many crustaceans, invertebrates and fishes for several decades. L. arcricus does not make an exception. Strong acid stress in pH 4 caused a high mortality of mature L. arcticus females. The critical lower limit of pH was 6.1 for the survival of this acid sensitive species. Thus, L. arcticus populations are probably in danger of extinction due to acidification of three ponds on Spitsbergen. A slight drop (0.1–1.0) in pH values can wipe out these L. arcticus populations. The survival of L. arcticus was strongly related to: (1) the water pH, (2) total organic carbon (TOC) and pH interaction, (3) the water temperature and (4) the water salinity. Water pH and TOC values should be monitored in these ponds and the input of acidifying substances in ponds should be prevented.
Now showing items 1-11 of 11