Effects of Current and Past Agricultural Practices on Arable Weed Diversity Across Landscape Complexity Gradients : a Case Study in Northern Romania
(2024) BION03 20231Degree Projects in Biology
- Abstract
- Our agricultural management practices have been constantly evolving, with significant impacts on both our society, and biodiversity of human-dominated landscape. While the negative effects of agricultural land-use change at local and landscape scales on biodiversity are well documented from regions such as Western Europe, the effect of current and past land-use in areas that have had more complex land-use intensity trajectories, such as larger parts of Central and Eastern Europe is less well understood. The study is based in Maramureș , NW Romania, an area where the coexistence of varying farming practices allows us to study the effects of farming practice development. By studying how arable weed community species richness, as well as... (More)
- Our agricultural management practices have been constantly evolving, with significant impacts on both our society, and biodiversity of human-dominated landscape. While the negative effects of agricultural land-use change at local and landscape scales on biodiversity are well documented from regions such as Western Europe, the effect of current and past land-use in areas that have had more complex land-use intensity trajectories, such as larger parts of Central and Eastern Europe is less well understood. The study is based in Maramureș , NW Romania, an area where the coexistence of varying farming practices allows us to study the effects of farming practice development. By studying how arable weed community species richness, as well as richness of rare species, depends on farming methods and environmental variables, we were able to determine that landscape complexity plays a more important role than farming practices. The use of fertilisers and herbicides did not have any effect on species richness, contrary to what we expected, but variables associated with elevation had a very strong positive effect. These results raise the question of the mechanisms with which landscape complexity diminishes the negative impacts of farming practices, and how we can use this knowledge in modern agriculture, where we strive to reduce the negative impacts of fertilisers and herbicides use on the surrounding ecosystems. (Less)
- Popular Abstract
- How the past continues to affect arable plant communities
Arable plant communities (a.k.a. weeds) are an important part of agriculture, which maintain some ecosystem products and services in an otherwise intensive land use. Their community composition can reduce and even improve crop yield, but the communities are often negatively impacted by the use of fertilisers and herbicides. Many studies have either focused on current management of these agroecosystems, past management, or landscape complexity, but rarely are they studied together. This could offer an interesting perspective on the long-term changes associated with land-use management. Finding a study area with different co-existing farming methods is usually the limiting factor... (More) - How the past continues to affect arable plant communities
Arable plant communities (a.k.a. weeds) are an important part of agriculture, which maintain some ecosystem products and services in an otherwise intensive land use. Their community composition can reduce and even improve crop yield, but the communities are often negatively impacted by the use of fertilisers and herbicides. Many studies have either focused on current management of these agroecosystems, past management, or landscape complexity, but rarely are they studied together. This could offer an interesting perspective on the long-term changes associated with land-use management. Finding a study area with different co-existing farming methods is usually the limiting factor in studying these conditions, but Maramureș in northern Romania is able to provide the conditions required for the study. The mix between vast policy changes, and limitations from remoteness, has allowed most of the farming methods of the past century to co-exist. In addition, substantial changes in agricultural practices from small subsistence, to large scale state owned farms, allow us to compare their effects on current plant communities.
We used 100 sites within the study area, controlling for soil type and crop plants within arable land sites. Wheat fields had 20 quadrats placed, and the presence/absence of species was recorded. Previous land use data was collected from the state archives and used to determine the past landscape complexity and land uses around the study sites. We separated landscape complexity into low, medium and high complexity using Shannon index of diversity. To determine current management practices, we interviewed 89 farmers for fertiliser, herbicide and other agrochemical inputs data. Using this data, we analysed the interactions between variables with general linear models, and selected the models with explained the data best.
We found that elevation was the only variable which affected the general weed species, the effect was positive, but likely only as a result of other variables affected by elevation, such as field size and landscape complexity. Herbicide and Fertilisers were not found to have an effect on species richness, which is contrary to research, as they are the main two factors reducing species richness of weeds. We did find that rare weed species were affected by past intensity and past landscape complexity. With increasing past intensity, complex landscapes had higher numbers of rare weed species, which is opposite of what is expected. Rare weed species are more common in arable landscapes with low past intensity, but in our study they were not, and became more common as the percentage of arable land increased, i.e. increasing intensity. On the other hand, simple landscapes decreased in rare species with increasing past intensity, and this is likely due to the negative impacts of intensification on rare species, and the absent dampening effect of landscape complexity. It is known that complex landscapes are able to reduce the impacts of intensification, and we have shown that this also works long-term, with past complex landscapes still having a positive effect regardless of current management.
Our results suggest that EU agricultural policy should focus on the long-term management of arable ecosystems as well as landscape complexity. We can use the benefits of landscape complexity and weed species communities to reduce the need for agrochemical inputs at the same time as preventing negative effects on crop yields.
Masters Degree Project in Plant Science; 60 credits; 2024
Department of Biology, Lund University
Supervisor: Prof. Yann Clough
Supervisor Department: Centre of Environmental Change (CEC) (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9184990
- author
- Bozga, Livius Calin
- supervisor
-
- Yann Clough LU
- organization
- course
- BION03 20231
- year
- 2024
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 9184990
- date added to LUP
- 2025-02-12 14:50:59
- date last changed
- 2025-02-12 14:50:59
@misc{9184990,
abstract = {{Our agricultural management practices have been constantly evolving, with significant impacts on both our society, and biodiversity of human-dominated landscape. While the negative effects of agricultural land-use change at local and landscape scales on biodiversity are well documented from regions such as Western Europe, the effect of current and past land-use in areas that have had more complex land-use intensity trajectories, such as larger parts of Central and Eastern Europe is less well understood. The study is based in Maramureș , NW Romania, an area where the coexistence of varying farming practices allows us to study the effects of farming practice development. By studying how arable weed community species richness, as well as richness of rare species, depends on farming methods and environmental variables, we were able to determine that landscape complexity plays a more important role than farming practices. The use of fertilisers and herbicides did not have any effect on species richness, contrary to what we expected, but variables associated with elevation had a very strong positive effect. These results raise the question of the mechanisms with which landscape complexity diminishes the negative impacts of farming practices, and how we can use this knowledge in modern agriculture, where we strive to reduce the negative impacts of fertilisers and herbicides use on the surrounding ecosystems.}},
author = {{Bozga, Livius Calin}},
language = {{eng}},
note = {{Student Paper}},
title = {{Effects of Current and Past Agricultural Practices on Arable Weed Diversity Across Landscape Complexity Gradients : a Case Study in Northern Romania}},
year = {{2024}},
}