From Fields to Food: The Hidden Impact of Agricultural Intensification (Ep. 41)

Habitat loss might not grab headlines like pesticides do, but it plays a critical role in pollinator diversity. We talk with Dr. Yi Zhou whose research in South China found semi-natural habitats provide essential nesting and food resources for mason bees. His findings highlight that fewer rice fields and more semi-natural landscapes contribute to greater pollinator diversity and survival rates.

Dr. Yi Zhou is an Associate Professor at Xian-Jiaotong Liverpool University in Suzhou, China. He’s an ecologist and entomologist studying conservation biology, landscape ecology and ecosystem services in agricultural and forest ecosystems. This is the study we discussed.

Good to know

Dr. Zhou doesn’t discount the threat of pesticides to native bees. The dual challenge of habitat preservation and pesticide management reflects the complexity of ecological stewardship. Dr. Zhou advocates for long-term monitoring to better understand the nuanced interactions between pollinators and their environments. The goal is a balanced approach that considers both pesticides and habitat loss, aiming for sustainable practices that support diverse ecosystems. We look more closely at pesticides and agriculture in episode 33.

Transcript

[00:00:00] Welcome to The Bee’s Knees. I’m your host, Jacy Meyer. The Bee’s Knees is a podcast wild about native bees. Wild and native bees are under threat worldwide. In each episode, we look at actionable things we can do to support these adorable little guys whose pollination work is crucial for maintaining biodiversity. Thanks for being here.

Bees face many stressors in their little lives. from pesticides to habitat loss, to climate change, to competition from non native species. But can we say which is the biggest threat? A fascinating study conducted in the rice fields of South China found something that may be a bit surprising. Habitat loss actually had a greater effect on pollinator diversity than pesticides.

Dr. Yi Zhou is an ecologist and entomologist studying conservation biology, landscape [00:01:00] ecology, and ecosystem services. He found there was more food available for female mason bees to feed their larvae with in regions with a lower percentage of rice fields and more semi natural habitat. Let’s learn more.

So your research indicated that the habitat loss that you found had a more significant impact on mason bee populations compared to pesticide exposures. Can you explain why the habitat loss is such a critical factor for these pollinators? So there, um, be two things. One is the habitat is provide the nesting place.

So natural and semi natural habitat. Provide a nesting place for a variety of wild pollinators. Another thing is about the food source, which can be also seen from our study that mason bee, the food acquisition is higher in landscape with higher proportion of semi natural [00:02:00] habitat. So these habitats are important for the species and the overall diversity.

Can you describe the semi natural habitat that you were looking at? . We didn’t look at all these details, but basically it can be separated into different groups. So like a lot of nature generated forest, secondary forest, and then the wild grasses, and then hedgerows. So basically it’s not a cropland, but they provide functions for species.

Yeah, but we didn’t look for all the species details for these habitats. So You found that the strong positive relationship between the mason bee food acquisition and the proportion of these semi natural habitats, whichever they may be, can you share some of what characteristics of these habitats are most beneficial to mason bees?

These semi nature habitat that including of [00:03:00] wild plants, wild trees, and they provide more resources, not just the more food and more proportion of the food, and we also found the survival rate of the mason bee is higher in the landscape with higher proportion of semi nature habitat. So in terms of the exactly what kind of species, plant species inside, Uh, we didn’t do it for that study, but I’m looking for that for the next study, trying to look at it from the pollen composition, and we want to know more details about that.

So kind of the big takeaway of this study was the importance of conserving these semi natural habitats around agricultural landscapes to support the pollinator diversity. Do you have any practical steps farmers or policymakers can take or recommendations that you would have to preserve or restore these habitats that are [00:04:00] in these agricultural landscapes?

Yeah, that’s um, good question. So the pollinator diversity in China is very high. It is likely due to the diverse and complex landscape for those smallholder agricultural ecosystem. And there’s in China, there’s a project of a large, uh, because you know, those small scale agriculture is not very easy for the machine to go to machinery processes.

So China is undergoing large scale land consolidation. Well, yes, this is so important for farmers and policymakers to be aware of the importance of the semi natural habitat in conserving pollinator diversity during land consolidation. I think on a way to conserve or restore some of these semi natural habitat.

might be needed to be aware during the land consolidation project. I think the message is important for policy makers and farmers. Even though your study found habitat loss to [00:05:00] be more damaging to the mason bees than pesticides, do you still feel it’s important to remember the effects of long term pesticide exposure?

I completely agree with that. Our study is just a snapshot. So the snapshot, although we did not find, in addition to the semi natural habitat of the additive effects, but the, it is apparently, there’s a lot of also studies reported that the pesticide affects the bees behavior. For example, the foraging ability.
I do have studies explore the Impact of the pesticide of forging behavior and learning acquisition and short term and long-term, uh, retention disabilities. So this influence could potentially affect the overall population size and the diversity for the long term. And I completely agree with that. And on the other way also.

Although our snapshot study did not find the relationship between pesticide exposure and the pollinator diversity across the [00:06:00] study site, but the impact of a pesticide cannot be ignored. We found more higher pesticide exposure. in the, uh, for the bee have a higher risk than in landscape with a more intensified rice field.

So this is a, this is a sign that suggests intensified agriculture land use resulted in a higher exposure of bees. in terms of the pesticide. Yeah. So where would you like to see the research go in this area? Um, so from this study, we still have a lot of aspects that are poorly understand. So basically, for example, we need, as you mentioned, we need long term monitoring of the pollinator diversity population and their exposure to the pesticide better inform the conservation effort.

As I said, that pollinator diversity, if you compare those kind of smallholder agriculture in China, if you compare [00:07:00] with the Europe, this is really high. So the pollinator diversity in Chinese smallholder agriculture system is very high, and we have to, this is an advantage, right? It’s an advantage. So we should be aware of this advantage, and take this advantage, and conserve.
Higher biodiversity instead of just ignoring it. So why bees? Why do you do what you do? I, in general, that, um, Bees are very important, like they provide crucial pollination services for many crops. And I’ve been working on the pollinator diversity for many years. So they are not just a functionally good, but they are, they are lovely.

People want to see more diversity. It’s good for our health and mental, and we just love it. Pollinator diversity in Chinese smallholder agricultural ecosystems is very high, which as Yi mentioned, is a good thing they need to remember and embrace. He believes this high diversity is due to the [00:08:00] diverse landscapes of these small farms.

He advocates conserving semi natural habitats in intensive agricultural landscapes, but doesn’t discount the impact of pesticides. The semi natural habitats provide more food and nesting resources, while agricultural intensification exposes bees to more pesticides. Thanks so much for joining me today, and I’d love it if you could recommend, review, or tell a friend about the show.
Until next time, support diversity.