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The relative contribution of vertebrates and invertebrates to ecosystem services and disservices after cereal harvest

Hjort, Cecilia (2017) BIOM01 20162
Degree Projects in Biology
Abstract
Structural changes to agricultural landscapes due to agricultural intensification caused declines in biodiversity and abundance of animal groups providing ecosystem services and disservices to agriculture. Little is known about the relative contribution of animals to services and disservices after harvest and how these animal groups are affected by landscape configuration. Therefore, this study investigated the quantitative differences of ecosystem service and disservice provision by vertebrates and invertebrates in agricultural landscapes after harvest. Additionally, potential effects of the surrounding landscape complexity and a local habitat contrast were studied. The study was conducted with three sampling dates during an 11-week... (More)
Structural changes to agricultural landscapes due to agricultural intensification caused declines in biodiversity and abundance of animal groups providing ecosystem services and disservices to agriculture. Little is known about the relative contribution of animals to services and disservices after harvest and how these animal groups are affected by landscape configuration. Therefore, this study investigated the quantitative differences of ecosystem service and disservice provision by vertebrates and invertebrates in agricultural landscapes after harvest. Additionally, potential effects of the surrounding landscape complexity and a local habitat contrast were studied. The study was conducted with three sampling dates during an 11-week period between August 24 and September 11 in 2016 in Skåne, Sweden. Feeding preferences for vertebrates and invertebrates were investigated through resources (crop (wheat) versus arable weed (common hemp-nettle) seeds and beneficial (earthworm) versus pest (wireworm-like larvae) animal prey) experiment and exclusion treatments to differentiate between vertebrate and invertebrate predation. In addition, wildlife cameras were used to differentiate the visiting vertebrates. Eight landscapes were selected within a landscape complexity gradient and two spring-sown cereal fields were chosen in each landscape adjacent to either a semi-natural grassland or a crop field. Postharvest preferences for resource types differed between sampling dates and the majority of the resource resources were consumed by vertebrates. Vertebrates generally provided a disservice through predation on crop seeds and beneficial prey; however pest invertebrates and weed seeds were consumed as well. Birds were more often recorded at the resource trays in fields adjacent to semi-natural grasslands compared to resource trays in fields next to another crop field. Bird records generally declined later in the postharvest season. Camera records at resource trays were dominated by small rodent species (mice). These results give new insights into disservices and services provided by vertebrates and invertebrates and suggest that mice contribute most dominantly to disservices and that semi-natural grasslands affect the presence and functional role of birds in crop fields after harvest. (Less)
Popular Abstract
Nature’s own helpers of agricultural enemies

Birds, rodents and invertebrates (insects) living among what looks like an ocean of barley and oat fields, with the occasional island of partially natural grassland popping up, helps keeping the fields from being taken over by enemies of the crops. The service they provide is called an ‘ecosystem service’. However, the helpers can occasionally get to greedy and nibble on the beneficial selection of seeds and insects, which then becomes a disservice.

Before the expansion of the ocean of barley and oat fields, additional and larger islands of partially natural grassland existed. Nature’s helpers were diverse and abundant. But due to more intense farming and changes of management techniques,... (More)
Nature’s own helpers of agricultural enemies

Birds, rodents and invertebrates (insects) living among what looks like an ocean of barley and oat fields, with the occasional island of partially natural grassland popping up, helps keeping the fields from being taken over by enemies of the crops. The service they provide is called an ‘ecosystem service’. However, the helpers can occasionally get to greedy and nibble on the beneficial selection of seeds and insects, which then becomes a disservice.

Before the expansion of the ocean of barley and oat fields, additional and larger islands of partially natural grassland existed. Nature’s helpers were diverse and abundant. But due to more intense farming and changes of management techniques, the biodiversity decreased. I wanted to investigate which of the groups of helpers that contributed the most to fighting off or not fighting off the enemies of the crops. To make it more intriguing, I wanted to investigate their contribution after the ocean of fields had been harvested, since little is known about postharvest ecosystem services and disservices. Additionally, I wanted to investigate how these structural changes to the fields affected the groups of helpers.

To find out which of the helpers who had been ‘naughty or nice’, a feeding preference experiment using four types of resources of food (beneficial crop seeds versus weed seeds and beneficial earthworms versus pest wireworm-like larvae) were performed. In addition, exclusion cages were used to differentiate between birds and rodents, and insects feeding of the resources of food. Wildlife cameras were used to differentiate between bird and rodent predation. Based on the amount of partially natural grassland in a 1-km radius, eight landscapes where selected with two cereal fields, either close to a partially natural grassland or a crop field, to perform the experiments in. The experiments were repeated for three rounds during the postharvest season.

Postharvest preferences for the type of food resources differed between rounds, and birds and rodents were the major consumers. Generally, birds and rodents tended to be a little too greedy and provided a disservice by consuming the beneficial selection of food resources. They also preferred plant seeds over insects- but who wouldn’t! However, they also fought off enemies of the crops. Birds were also more often present at offered food resources in fields adjacent to partially natural grasslands compared to fields next to another crop field. The camera records showed us that birds generally declined later in the postharvest season and that small rodents (mice) were the most common visitor of the offered food resources.

These results give new insights into disservices and services provided by nature’s helpers, suggesting that mice dominantly contribute to disservices and might not be as helpful as previously thought. Therefore, more research is needed to differentiate how services could be enhanced without simultaneously promoting disservices. To end on a more positive note, the islands of partially natural grasslands in the ocean of fields positively affected the presence and functional role of birds in crop fields after harvest. I suggest from a conservationist point of view, that agricultural management practices should take the importance of preserving these partially natural grasslands into consideration to provide breeding, living and refuge habitat for the group of helpers, the birds.

Master’s Degree Project in Conservation biology 30 credits 2017
Department of Biology, Lund University
Advisor: Klaus Birkhofer and Matthias Tschumi (Less)
Please use this url to cite or link to this publication:
author
Hjort, Cecilia
supervisor
organization
course
BIOM01 20162
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8904392
date added to LUP
2017-03-09 12:20:45
date last changed
2017-03-09 12:20:45
@misc{8904392,
  abstract     = {Structural changes to agricultural landscapes due to agricultural intensification caused declines in biodiversity and abundance of animal groups providing ecosystem services and disservices to agriculture. Little is known about the relative contribution of animals to services and disservices after harvest and how these animal groups are affected by landscape configuration. Therefore, this study investigated the quantitative differences of ecosystem service and disservice provision by vertebrates and invertebrates in agricultural landscapes after harvest. Additionally, potential effects of the surrounding landscape complexity and a local habitat contrast were studied. The study was conducted with three sampling dates during an 11-week period between August 24 and September 11 in 2016 in Skåne, Sweden. Feeding preferences for vertebrates and invertebrates were investigated through resources (crop (wheat) versus arable weed (common hemp-nettle) seeds and beneficial (earthworm) versus pest (wireworm-like larvae) animal prey) experiment and exclusion treatments to differentiate between vertebrate and invertebrate predation. In addition, wildlife cameras were used to differentiate the visiting vertebrates. Eight landscapes were selected within a landscape complexity gradient and two spring-sown cereal fields were chosen in each landscape adjacent to either a semi-natural grassland or a crop field. Postharvest preferences for resource types differed between sampling dates and the majority of the resource resources were consumed by vertebrates. Vertebrates generally provided a disservice through predation on crop seeds and beneficial prey; however pest invertebrates and weed seeds were consumed as well. Birds were more often recorded at the resource trays in fields adjacent to semi-natural grasslands compared to resource trays in fields next to another crop field. Bird records generally declined later in the postharvest season. Camera records at resource trays were dominated by small rodent species (mice). These results give new insights into disservices and services provided by vertebrates and invertebrates and suggest that mice contribute most dominantly to disservices and that semi-natural grasslands affect the presence and functional role of birds in crop fields after harvest.},
  author       = {Hjort, Cecilia},
  language     = {eng},
  note         = {Student Paper},
  title        = {The relative contribution of vertebrates and invertebrates to ecosystem services and disservices after cereal harvest},
  year         = {2017},
}