Popular Science: What is the bird species diversity in traditional fruit orchards?
One of the most important issues in ecology and conservation is how abiotic conditions affect the occurrence of certain organisms. At the same time, birds represent an important part of the entire ecosystem and could be also used as indicators of biodiversity.
The aim of the study was to find out the influence of topography, patch and land use on the conservation trait status of birds (with regard to their rarity and red-list index) in a selected area within the Pardubice Region. It was a predominantly agricultural landscape with only smaller rural villages. More than half of the landscape consisted of arable land, while the rest included permanent grassland, forests dominated mainly by Scots pines and Norway spruces with smaller island-like patches of sessile, oaks, beeches and hornbeams.
The team of experts visited the study area several times. In total, there were 68 traditional orchards with an area of up to a quarter of a hectare, representing the remnants of agroforestry. Observations and counting in each of the orchards took place three times per year from dawn to late morning in the spring months, with the research lasting two years (2011–2012). The resulting abundance of each species on each plot was determined using the highest count from the six visits.
In total, the researchers observed 57 bird species, of which 31 could be classified as forest dwellers and 16 as farmland dwellers. They determined also the rarity of occurrence in the Czech Republic and the red-list index status using IUCN (International Union for Conservation of Nature) criteria for each bird species.
Among the conditions influencing the occurrence of birds, 11 predictors were chosen, divided into three basic groups - patch, land use and topography. All three predictors were significant in terms of the rarity and red-list index, with the topography being the most important. The results showed the most balanced values of influencing factors for farmland bird traits, while woodland bird traits were more influenced by the patch configuration (included canopy openness, shrub coverage and surrounding) than by other factors.
An interesting finding was that the number of specialists in traditional fruit orchards prevailed over opportunists who do not have special preferences (there were only 12.5% of them in the total population), with greater number of woodland-preferring species. Traditional fruit orchards have thus been shown to be suitable for a variety of bird species, including endangered species such as Jynx torquilla or Coturnix coturnix. The authors point out the importance of further research with more attention focused on the possible influence of interactions among and between predictors, and especially their categories.
Bird species diversity is declining around the world together with landscape changes and biodiversity loss. Some people consider certain areas in the landscape, such as meadows and forests, to be of low economic value, but the opposite is true. These areas contribute to the increased biodiversity and bird species diversity, which contribute to the landscape stabilization against possible increased imbalances (such as the overpopulation of voles and insects). Current research has shown that even traditional fruit orchards promote a high degree of diversity within bird communities. However, it is necessary to pay attention to biodiversity and proper sustainable management of traditional fruit orchards – let us be kind to nature, we will get as much as we give.
Zasadil, P., Romportl, D., Horák, J. (2020): Disentangling the Roles of Topography, Patch, and Land Use on Conservation Trait Status of Specialist Birds in Marginal Forest Land Use Types. Forests, 11, 103; doi:10.3390/f11010103