Climate change and global warming affect both humans and nature in many ways. One of the sectors that is most affected is the agricultural industry because both drought and excessive rainfall pose significant problems. Agricultural lands, especially meadows and pastures, are among the most species-rich environments. Due to changing land use such as exploitation and a challenging economic situation, many farmers choose to terminate their businesses. In Jämtland County, Sweden, the number of notifications to take their agricultural land out of production is increasing, resulting in a decrease in the agricultural land area, which in turn means negative consequences for biodiversity. This study therefore examines the consequence of declining agricultural land areas (pasture land) for a species strongly linked to these environments – the violet copper butterfly (Lycaena helle). The hypothesis is that the violet copper has decreased in occurrence in the last 20 years (2003–2023) as pasture land areas have been reduced in Jämtland. To investigate this, correlation analyzes were made between species observations in Jämtland over the last 20 years (2003–2023) and data for pasture land areas for the same period. The correlation analysis was carried out for species observations from the Swedish Species Observation System (SLU Artdatabanken) and from the Swedish Butterfly Monitoring (Svensk Dagfjärilövervakning) to compare whether the outcomes were different depending on the data source. None of the statistical tests showed any significant positive correlation (p >0.05), which meant that the hypothesis was not correct. In contrast, the correlation results for the two different data sources implied different trends: Swedish Species Observation System's findings shows a negative correlation (r= -0.408; p = 0.074; 2-tailed) indicating an increasing population size and the Swedish Butterfly Monitoring data shows a positive correlation (r= 0.449; p = 0.225; 2-tailed) indicating a decreasing population size. However, estimating total population size is challenging, so targeted repeated inventories on the same sites over a long period of time are recommended (similar to the Swedish Butterfly Monitoring program) to obtain accurate and reliable datasets for analyses. It is difficult to determine whether climate change is directly affecting the violet copper, but the indirect effects such as land use change, exploitation and abandoned agricultural land most likely do. This study further recommends research on the isolation effects on the Swedish population (genetic variation), further consequences of land use change and the species' habitat requirements (ecology). / Klimatförändringarna och den globala uppvärmningen påverkar både människan och naturen på många sett. En av de sektorer som drabbas hårdast är jordbruksverksamheten eftersom dels torka, dels för hög nederbörd innebär stora problem. Jordbruksmarker, framför allt ängs- och betesmarker är en av de artrikaste miljöer som existerar. På grund av förändrad markanvändning som exploatering och en utmanande ekonomisk situation väljer många jordbrukare att lägga ned sina verksamheter. I Jämtland ökar antalet anmälningar att ta sin jordbruksmark ur produktion vilket resulterar i att jordbruksarealen minskar vilket i sin tur innebär negativa konsekvenser för den biologiska mångfalden. Den här studien undersöker därför konsekvensen av minskande jordbruksarealer (betesmarker) för en art som är starkt kopplad till dessa miljöer – violett guldvinge (Lycaena helle). Hypotesen är att violett guldvinge har minskat i förekomst de senaste 20 åren (2003–2023) i takt med att betesmarkarealerna reducerats i Jämtlands län. För att undersöka detta gjordes korrelationsanalyser mellan artfynd i Jämtland de senaste 20 åren (2003–2023) och data för betesmarksarealer för samma period och område. Dels gjordes korrelationsanalysen med fynd från SLU Artdatabanken, dels från Svensk Dagfjärilsövervakning för att jämföra om utfallet blev annorlunda beroende av datakälla. Ingen av de statistiska testerna visade någon signifikant positiv korrelation (p >0,05), vilket innebar att hypotesen inte stämde. Däremot antydde korrelationsresultaten mellan de två olika datakällorna olika trender: SLU Artdatabankens fynd visar en negativ korrelation (r= -0,408; p = 0,074; 2-tailed) vilket indikerar på en ökande population medan Svensk Dagfjärilsövervakning visar en positiv korrelation (r= 0,449; p = 0,225; 2-tailed) vilket indikerar på en minskande population. Att uppskatta populationsstorlekar är dock utmanande, så riktade inventeringar på återkommande lokaler under lång tid rekommenderas (i likhet med Svensk Dagfjärilsövervakning) för att få ackurata och trovärdiga dataset att analysera. Det är svårt att avgöra om klimatförändringarna direkt påverkar den violetta guldvingen, men de indirekta effekterna som förändrad markanvändning, exploatering och övergivna jordbruksarealer gör det sannolikt. Studien rekommenderar vidare forskning kring det svenska beståndets isoleringseffekter (genetisk variation), ytterligare konsekvenser av förändrad markanvändning och artens habitatkrav (ekologi).

The violet copper (Lycaena helle) is one of Europe’s most endangered butterflies as a result of loss and fragmentation of its habitat. In order to further understand the habitat requirements of this species it is important to observe the specific characteristics of the oviposition sites. There is little research on L. helle in Sweden and the least in the northern parts. In this study I searched for eggs and larvae along a seashore meadow in Norrbotten County where a substantial number of L. helle recently had been found. The area differed from the species’ usual habitat in that the host plant Bistorta vivipara was scarce in large parts. The coastline was split into two areas for comparison according to vegetation type and direction of the shore, one seemingly more suitable for L. helle and the other less so. The results showed that oviposition sites had a lower coverage of, and average height, of the surrounding vegetation than potential oviposition sites without eggs. The coverage of the host plant did not differ between oviposition sites and sites without eggs. Most of the eggs were found on the first area where, surprisingly, a few Bistorta vivipara had up to eight eggs on a single leaf. The sometimes complete lack of eggs on the second area, while still containing a reasonable amount of Bistorta vivipara, confirms that the presence of the host plant is not enough for the females to lay eggs and that any host plant will not be chosen as an oviposition site. The amount of eggs found in the first area together with its structure and east-facing shore further confirms that this species is dependent on lower and more sparse vegetation together with high solar radiation.