Biology subjects

Nottebrock, H.

Publications and source records attributed to Nottebrock, H..

5 recordsLinked to original sources

bioRxiv2024

Interactions between Brassica carinata and its pollinators is shaped by managed beehives and neonicotinoid seed treatment

Brassica carinata is a biofuel and animal feed crop with expanding global production. Although there is much research on common farming practices to improve yield, there is almost a complete absence of data on the dependency of yield through pollination services. Reciprocally, we lack information on whether B. carinata offers ecosystem services to pollinators. We observed almost 4000 pollinator visits, quantified different plant functional traits, including floral resources and examined the effect of supplementing fields with honey bee hives and the use of neonicotinoid seed treatment on seed yield and honey bee health. Data was collected from 35 0.404-ha sites with more than 800 focal B. carinata individuals across 2 years in the Prairie Coteau region of the Northern Great Plains. We found that pollinators (n = 28 species) are attracted to floral resources at different spatial scales. High visitation rates by pollinator species were associated with double the seed set in B. carinata relative to the lowest visitation rates. Brassica carinata adds floral resources to the agricultural ecosystem and therefore has the potential to increase pollinator health. However, species interactions are influenced by the use of insecticides and the presence of honey bees by managed beehives. In particular, insecticides alter the role of pollinators on crop pollination by reducing the positive impact of floral resources on pollinator-mediated yield and honey bee health.

ecology↗

bioRxiv2021

Quantifying habitat and landscape effects on composition and structure of plant-pollinator networks in the US Northern Great Plains

Community structure contributes to ecosystem persistence and stability. To understand the mechanisms underlying pollination and community stability of natural areas in a human influenced landscape, a better understanding of the interaction patterns between plants and pollinators in disturbed landscapes is needed. The Northern Great Plains still retain extensive tracts of remnant temperate grassland habitat within a matrix of varying land-uses. We used a network-based approach to quantify how temperate grassland attributes and landscape heterogeneity influence plant-pollinator community structure in natural habitats. We also quantified pollinator diversity and floral diversity to assess the functional role of temperate grassland attributes and the surrounding landscape on the composition of the plant-pollinator communities in natural habitats. We found that the amount of local nectar sugar and increased proportions of certain land-uses contribute to pollinator diversity that in turn influences the structure of interactions between plants and pollinators. Understanding the factors contributing to plant-pollinator network structure can guide management decisions to support resilient plant-pollinator communities and conserve the stability of pollination services.

ecology↗

bioRxiv2019

Maximizing Ecosystem Services Provided To The New Oil Crop Brassica carinata Through Landscape And Arthropod Diversity

Prairies, once spanning the Upper Midwest, have now largely been replaced by agriculture. The lack of resources available to pollinators in agricultural fields and practices commonly employed has led to a decline in insect diversity. To enhance sustainable practices, we must better understand how ecosystem services such as pest control and pollination services provided by a diverse insect and pollinator community scale to current farming practices as related to crop yield and how landscape features may positively contribute to insect and pollinator diversity. We examined how landscape heterogeneity relates to insect and pollinator diversity, as well as how insect and pollinator diversity relates to crop yield across common farming practices. We planted 35 single acre sites of Brassica carinata, a generalist flower possibly capable of supporting a diverse insect community. We randomly assigned each site with a combination of three common farming practices: tilling (yes/no), added honey bee hives (yes/no), and treatment with systemic neonicotinoids (yes/no). Insect and pollinator diversity and the surrounding landscape at multiple spatial scales were calculated. We observed a significant positive relationship between insect (and pollinator) diversity with yield in the absence of any farming practice. All farming practices will increase yield. However, farming practices alter the relationship between yield and diversity. The addition of seed treatment or tillage negates the relationship between insect (and pollinator) diversity with yield. Seed treatment alone results in a flat relationship between diversity and yield for all insects and a negative relationship for pollinators. Increased landscape heterogeneity results in a positive relationship between insect diversity at the 1000 m scale and pollinator diversity at the 3000 m scale, suggesting large-scale heterogeneity contributes to overall insect diversity. Our results show that increasing large-scale landscape heterogeneity increases diversity serving as a substitute for common farming practices such as application of pesticides, tilling, or bee hives. Increased heterogeneity could save farmers from the input cost of treatment or tillage, by way of increased insect diversity, while still providing similar yields.

ecology↗

bioRxiv2019

Mismatches between niches and geographic ranges of plants depend on life history traits

The ecological niche of a species describes the variation in population growth rates along environmental gradients that drives geographic range dynamics. Niches are thus central for understanding and forecasting species geographic distributions. However, theory predicts that migration limitation, source-sink dynamics and time-lagged local extinction can cause mismatches between niches and geographic distributions. It is still unclear how relevant these niche-distribution mismatches are for biodiversity dynamics and how they depend on species life history traits. This is mainly due to a lack of the comprehensive, range-wide demographic data needed to directly infer ecological niches for multiple species. Here we quantify niches from extensive demographic measurements along environmental gradients across the geographic ranges of 26 plant species (Proteaceae; South Africa). We then test whether life history explains variation in species niches and niche-distribution mismatches. Niches are generally wider for species with high seed dispersal or persistence abilities. Life history traits also explain the considerable interspecific variation in niche-distribution mismatches: poorer dispersers are absent from larger parts of their potential geographic ranges, whereas species with higher persistence ability more frequently occupy environments outside their ecological niche. Our study thus identifies major demographic and functional determinants of species niches and geographic distributions. It highlights that the inference of ecological niches from geographical distributions is most problematic for poorly dispersed and highly persistent species. We conclude that the direct quantification of ecological niches from demographic responses to environmental variation is a crucial step towards a better predictive understanding of biodiversity dynamics under environmental change.

ecology↗

bioRxiv2018

Rapid evolution of spontaneous mutation increases genetic diversity facilitating plant population survival

Using a mechanistic eco-evolutionary trait-based neighborhood-model, we quantify the impact of mutations on spatial interactions to better understand the potential effect of niche evolution through mutations on the population dynamics of Arabidopsis thaliana. We use 100 twenty-fifth generation mutation accumulation (MA) lines (genotypes) derived from one founder genotype to study mutational effects on neighbor responses in a field experiment. We created individual-based maps (15,000 individuals), including phenotypic variation, to quantify mutational effects within genotypes versus between genotypes on reproduction and survival. At small-scale, survival is enhanced but reproduction is decreased when a genotype is surrounded by different genotypes. At large-scale, seed set is facilitated by different genotypes while the same genotype has either no effect or negative effects. Mutations may provide a mechanism for plants to quickly evolve niches and may drive competition, facilitation and selection with profound consequences for future population and community dynamics.

ecology↗