Vedlevande skalbaggar och andra naturvärden i brukad bokskog - En fallstudie av Tingvallaravinen i Skåne

Abstract

Nature is in many ways crucial for human survival. However, due to human activity and exploitation, unique species and habitats are at risk of extinction. The forest is one habitat that has been deeply afflicted. A massive loss of forests worldwide due to intense forestry has led to a defeat of biodiversity. Saproxylic beetles is one group of forest dwellers that has been affected by habitat loss. The deficiency of dead wood leaves several species at risk of extinction. The aim of the study was to investigate the nature values in a forestry area focusing on saproxylic beetles. The study was performed as a case study of a forestry area called Tingvallaravinen in southern Sweden.

A beetle survey was performed using two kind of traps (window traps and pitfall traps) and two manual methods (netting and active search). The beetle survey was combined with a deadwood survey and a nature assets survey (used to identify valuable biotopes and element). To understand the areas nature value in a landscape perspective previous founding of saproxylic beetles in three protected nature areas in proximity of the study area was scrutinised.

A total of 186 specimen of 56 beetle species were trapped, of which 20 were saproxylic. Three red-listed species, Prionus coriarius, Eucnemis capucina and Triplax rufipes (all saproxylic), were identified. The dead wood survey revealed that, on average the area holds 1.4 logs of dead wood/ha and the volume of dead wood totalled to 1.9m3/ha. The nature assets survey resulted in the identification of ten nature value object, of which five was given nature value class 2 (second to the highest).

The results indicate that the forest area of Tingvalla is a low-quality habitat for saproxylic beetles. The species present in the area has either migrated there from protected areas close by (in a source-sink dynamic) or exist as a relict population. However, the presence of saproxylic beetles indicates that the area despite flaws, works as habitat for the beetles. Thus, do the area contribute with habitat in the over-all landscape, a part that can be strengthen if the habitat quality improves. Conservation schemes should therefore aim to conserve and develop the forests valuable nature assets and to protect endangered species.

Popular Abstract (Swedish)

Naturen är på många sätt avgörande för människans fortlevnad. På grund av mänsklig aktivitet och exploatering riskerar unika arter och naturtyper att gå förlorade. Skogen är en av de miljöer som är hårt drabbad. Intensivt skogsbruk har lett till en kraftig minskning i mängden skog världen över med förlust av biologisk mångfald som följd. En viktig skogslevande grupp som drabbas av habitatminskning är de vedlevande skalbaggarna. Bristen på död ved i skogarna gör att flera arter riskerar utrotning. Syftet med studien var att undersöka hur naturvårdsarbete kan bedrivas för att motverka förlusten av biologisk mångfald. Studien utfördes som en fallstudie av ett brukat skogsområde, Tingvallaravinen, i södra Sverige.

För att ta reda på vilka naturvärden som fann inom studieområdets inventerades dess skalbaggsfauna med hjälp av fönster- och fallfällor samt med två manuella metoder (slaghåvning och aktivt sökande). Fältinventeringen inkluderade även en kartläggning av den döda ved som fanns i området. En naturvärdesinventering genomfördes för att identifiera viktiga biotoper och värdefulla element. Vidare studerades tidigare fynd av vedlevande skalbaggar i tre skyddade naturområden, på olika avstånd från studieområdet för att förstå dess naturvärde i ett landskapsperspektiv.

Totalt samlades 186 skalbaggar, fördelade på 56 arter, in. Av dessa var 20 arter vedlevande. Tre rödlistade arter, Prionus coriarius, Eucnemis capucina och Triplax rufipes (alla vedlevande), hittades. Inventeringen av död ved visade att det i genomsnitt fanns 1.4 stockar/ha och att volymen uppgick till 1.9m3/ha. Tio naturvärdesobjekt identifierades varav fem gavs naturvärdesklass 2 (näst högst).

Resultaten tyder på att den brukade skogen kring Tingvalla utgör ett lågkvalitativt habitat för vedlevande skalbaggar. De arter som återfanns har antingen spridits dit från närliggande naturskyddsområden (i en källa-sänkadynamik) eller lever kvar som en relikt population. Förekomsten av vedlevande skalbaggar tyder dock på att området, trots brister, fungerar som livsmiljö för dessa arter. Tingvallaravinen bidrar med habitat ur ett landskapsperspektiv, en roll som kan stärkas om habitatkvaliteten förbättras. Naturvårdsåtgärder som utformads bör således syfta till att bevara och utveckla skogens naturvärden och skydda hotade arter.



Nature is in many ways crucial for human survival. However, due to human activity and exploitation unique species and habitats are at risk of extinction. The forest is one habitat that has been deeply afflicted. A massive loss of forests worldwide due to intensive forestry has led to a defeat of biodiversity. Saproxylic beetles is one group of forest dwellers that has been affected of habitat loss. The deficiency of dead wood leaves several species at risk of extinction. The aim of the study was to investigate which nature conservation methods that can be used to militate the loss of biodiversity. The study was performed as a case study of a forestry area called Tingvallaravinen in southern Sweden.

A beetle survey was performed using two kind of traps (window traps and pitfall traps) and two manual methods (netting and active search). The beetle survey was combined with a deadwood survey and a nature assets survey (used to identify valuable biotopes and element). To understand the areas nature value in a landscape perspective previous founding of saproxylic beetles in three protected nature areas in proximity of the study area was scrutinised.

A total of 186 specimen of 56 beetle species were trapped, of which 20 were saproxylic. Three red-listed species, Prionus coriarius, Eucnemis capucina and Triplax rufipes (all saproxylic), were identified. The dead wood survey revealed that, on average the area holds 1.4 logs of dead wood/ha and the volume totalled to 1.9m3/ha. The nature assets survey resulted in the identification of ten nature value object, of which five was given nature value class 2 (second to the highest).

The results indicate that the forest area of Tingvalla is a low-quality habitat for saproxylic beetles. De species present in the area has either migrated there from protected areas close by (in a source-sink dynamic) or exist as a relict population. However, the presence of saproxylic beetles indicates that the area, despite flaws works as habitat for the beetles. Thus, do the area contribute with habitat in the over-all landscape, a part that can be strengthen if the habitat quality improves. Conservation schemes should therefore aim to conserve and develop the forests valuable nature assets and to protect endangered species.

• author: Björk, Amanda
• supervisor: Andreas Nord; Maria von Post
• organization: Degree Projects in Biology
• course: BIOM02 20202
• year: 2021
• type: H2 - Master's Degree (Two Years)
• subject: Biology and Life Sciences
• language: Swedish
• id: 9043312
• date added to LUP: 2021-04-23 15:46:43
• date last changed: 2021-04-23 15:46:43