Posted by Darren Ward @nzhymenoptera

Trees are mostly made of woody stuff. Sometimes this stuff breaks and falls on the ground. It’s called coarse woody debris (CWD).

CWD is considered a ‘wasted’ resource if it just lies around in a forest. Not so! Overseas, the role of CWD has often been heavily studied for its role in restoration, succession, nutrient recycling, and in maintaining the diversity of invertebrates, fungi, et al. But this appears not to be the case for New Zealand, at least from an entomological perspective.

Good use of CWD

Less good use of CWD

 

Some of our recent work had highlighted the entomological importance of CWD in forests in the Waitakere Ranges. Our broad aim has been to examine the abiotic factors affecting the diversity of invertebrates, and more specifically different groups of wasps, both native and exotic species.

In each of the studies completed so far, CWD has been a key factor in influencing insect diversity, both the number of species, and the functional diversity of communities.

For example, the abundance of parasitoid wasps in the subfamily Cryptinae, who predominantly attack wood-boring insects (e.g. the larvae of beetles, caterpillars), were positively associated with total CWD volume; while parasitoids that predominantly attack larvae on exposed surfaces such as leaves were negatively related to CWD volumes. Our results also suggest many parasitoid species (and their hosts) utilise small sized pieces of dead wood, indicating the importance of having a range of resources in an environment.

CWD also affects the community structure of spider-hunting wasps (Pompilidae), where greater CWD volume facilitates greater species richness; and specialist deadwood species are only present in areas with higher volumes of CWD.

However, CWD not only influences native insect communities. It also plays a role in regulating the density of an exotic wasp, Meteorus pulchricornis. Here, densities of this parasitoid declined with increasing coarse woody debris, suggesting some type biotic resistance mechanism where Meteorus pulchricornis is less able to invade native forests.

So CWD, it’s cool. Keep it. For the bugs.

Darren Ward is an entomologist in the New Zealand Arthropod Collection at Landcare Research, and a senior lecturer at the School of Biological Sciences, University of Auckland.

Kendall L, Ward DF. 2016. Habitat determinants of the taxonomic and functional diversity of parasitoid wasps. Biodiversity & Conservation. 25(10), 1955-1972i

Kendall L, Ward DF. The role of habitat variability in determining community structure of spider-hunting wasps (Hymenoptera: Pompilidae). Submitted!

 McGrath Z. 2017. Quantifying the ecological risk of exotic species–a case study using the parasitoid Meteorus pulchricornis. MSc Thesis, University of Auckland. Almost submitted!!

Posted by Julia Schmack PhD student at the University of Auckland @julia_schmack

Powerful politicians are denying climate change, mega companies are patenting the seeds of our planet, and ecosystems are exploited for cheap resources at horrendous ecological costs. There are a few more things to add to this list which most of us, working in Biological Science, are aware of. By the way, why did you choose Biology? I reckon I became an ecologist because I have always been fascinated by the colors, shapes, sounds, tastes, smells, textures and especially by the stories that nature provides. Growing up, I found that there are a lot of horror stories going on as well, stories about how we treat forests, water, soil and animals. I thought that knowledge must be the key to prevent people from abusing nature. But sometimes this key doesn’t even get you through the gate of people’s minds onto their front lawn.

Open Gates

Fortunately I found plenty of open doors at the kindergartens I worked with for the last 3 years before coming to New Zealand to start my PhD with the Ecology Ngatahi group. I gave courses for teachers on how to create biodiverse organic gardens with wild herbs and flowers as well as forgotten native fruit and vegetable varieties and nesting sites for beneficial animals in a network of 200 kindergartens. It was fun to work with adults and see how they lose their fear of spates, drills and saws.

    

But the most rewarding part of my work for the project and as a freelance environmental educator (www.julia-schmack.de) were the days I spent working with children. Most of the groups consisted of children at the age between 4-9 years old. We built nesting boxes for bees, compiled bug beds, dug ponds and planted “snack gardens”. The children’s questions and observations were so fresh and naïve that there was no room for prepared answers. We investigated every single ‘hypotheses’ on what would be the most adequate house for some of our native bees. There are 547 species of native bees in Germany. More than half of them (53%) are endangered due to severe reductions in nesting habitats and a pivotal decrease of their food resource, native plants (Westrich et al., 2011).

Our global garden

Globally, pollinators are threatened by climate change, the spread of alien species and diseases and land-use intensification (Vanbergen et al., 2013). International studies on the ecological and economical value of pollination highlight our strong dependency on insect pollinators for agricultural food production. Wild pollinators increase and stabilize crop-pollination services and wild bees in particular are known to improve fruit set, quality and commercial value of various crops. But this remarkable ecosystem service provided by wild bees shows severe decreases in many parts of the world under the pressure of agricultural land-use intensification (Potts et al., 2016).

We All Love Stories

For the kids the most intriguing question was “where do we find the bees?”. Working the answers out along their own question, they elaborated the story of ‘the native bees in need’ and decided to help them. Being a wild bee, they imagined, it must be hard to find a place to nest and stay over winter. They also worked out that there is not much to eat if you only like native plants. Don’t worry, there is evidence that children are interested in and understand complex environmental concepts (Grodzinska-Jurczak et al. 2006; Palmer and Suggate 2004). So here we go! Step by step we replaced the backyard lawn with wild herbs, native flowers and fruiting trees. We built nesting blocks and put up water bowls. When the first native bees colonized the blocks, the garden became a well frequented observation spot as the kids proudly presented their project to their friends and families. They explained the bee’s story to other children and presented a local solution to a global problem.

Find a short take on native bees colonizing nesting blocks on our Ecology Ngatahi Youtube Channel.

Nature and Health

Chawla et al. (2014) showed that green schoolyards “enable students to escape stress, focus, build competence and form supportive social groups”. The natural areas helped children to develop protective factors for resilience and stress management. The four main reasons for favorable reactions on green schoolyards by children: “being outdoors in fresh air”; “feeling connected to a natural living system”; “successfully caring for living things”; and “having time for quiet self-reflection” (Chawla et al., 2014). Bratman et al. (2015) conducted a study on adults and the impact of nature walks versus urban walks on affect and cognition. They found that a 50 minute nature walk decreased anxiety levels as well as rumination and increased working memory performance in participants. A study on students showed that a 40 minute walk in nature has a buffering effect on chronic stress (Olafsdottir et al. 2016).

Key studies

These studies underline that outdoor experiences are beneficial for human health. But do nature experiences also influence our behavior towards nature? Could they be a key to open gates and foster ecological awareness? Studies in kindergartens, elementary schools and outdoor camps demonstrate that outdoor experiences and direct interactions with nature during early childhood are linked to a positive attitude toward the environment and a stronger motivation to get involved in nature protection (Elliot et al., 2014, Collado et al., 2013, Bögeholz 2006, Palmberg and Kuru 2000, Chawla 1998).

My Conclusion

To me, hands on environmental education was a fantastic way to communicate what I would like to pass on to children. I reckon, I just used the same key that was used to open my mind to nature when I was a child. So there must be many more keys out there. Let’s go and pass them on to the next generation!

Julia Schmack is a PhD student at the Centre for Biodiversity & Biosecurity, School of Biological Sciences, University of Auckland. She is researching the ecology and control of Vespula wasps, supervised by Jacqueline Beggs, Darren Ward and Mandy Barron (Landcare Research).  Her PhD is funded by the Biological Heritage National Science Challenge.

References

• Bögeholz S, 2006, Nature Experience and Its Importance for Environmental Knowledge, Values and Action: Recent German Empirical Contributions. Environmental Education Research 12: 65–84.
• Bratman GN, Daily GC, Levy BJ, Gross JJ, 2015, The benefits of nature experience: Improved affect and cognition. Landscape and Urban Planning 138(2015):41–50
• Chawla L, 1998, Significant Life Experiences Revisited: A Review of Research on Sources of Environmental Sensitivity. Environmental Education Research 4: 369-382.
• Chawla et al., 2014, Green schoolyards as havens from stress and resources for resilience in childhood and adolescence. Health & Place 28(2014):1–13.
• Collado S, Staats H, Corraliza JA, 2013, Experiencing Nature in Children’s Summer Camps: Affective, Cognitive and Behavioral Consequences. Journal of Environmental Psychology 33: 37-44.
• Eilers EJ, Kremen C, Greenleaf SS, et al., 2011, Contribution of pollinator-mediated crops to nutrients in the human food supply. PLoS ONE 6: e21363.
• Elliot E, Eycke KT, Chan S, Mueller U, 2014, Taking Kindergartners Outdoors: Documenting Their Explorations and Assessing the Impact on Their Ecological Awareness. Children, Youth and Environments 24(2):102-122.
• Grodzinska-Jurczak M, Stepska A, Nieszporek K, Bryda G, 2006, Perception of Environmental Problems among Pre-School Children in Poland. International Research in Geographical and Environmental Education 15: 62-76.
• Palmberg IE, Kuru J, 2000, Outdoor Activities as a Basis for Environmental Responsibility. Journal of Environmental Education 31: 32-36.
• Palmer JA, Suggate J, 2004, The Development of Children’s Understanding of Distant Places and Environmental Issues: Report of a UK Longitudinal Study of the Development of Ideas between the Ages of 4 and 10 Years. Research Papers in Education 19: 205-237.
• Vanbergen AJ, the Insect Pollinators Initiative, 2013, Threats to an ecosystem service: pressures on pollinators. Frontiers in Ecology and the Environment 11(5):251–259, doi:10.1890/120126.
• Westrich P, Frommer U, Mandery K, Riemann H, Ruhnke H, Saure C, & Voith J, 2011, Rote Liste und Gesamtartenliste der Bienen (Hymenoptera, Apidae) Deutschlands. – In: Binot-Hafke M, Balzer S, Becker N, Gruttke H, Haupt H, Hofbauer N, Ludwig G, Matzke-Hajek G & Strauch M (Red.): Rote Liste gefährdeter Tiere, Pflanzen und Pilze Deutschlands. Band 3: Wirbellose Tiere (Teil 1). – Münster (Landwirtschaftsverlag). – Naturschutz und Biologische Vielfalt 70 (3): 373-416.