| 1. |
- Faticov, Maria, et al.
(författare)
-
Climate and host genotype jointly shape tree phenology, disease levels and insect attacks
- 2020
-
Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 129:3, s. 391-401
-
Tidskriftsartikel (refereegranskat)abstract
- One of the best known ecological consequences of climate change is the advancement of spring phenology. Yet, we lack insights into how changes in climate interact with intraspecific genetic variation in shaping spring and autumn phenology, and how such changes in phenology will translate into seasonal dynamics of tree-associated organisms. To elucidate the impact of warming and tree genotype on spring and autumn phenology, as well as the consequences for the population dynamics of a fungal pathogen Erysiphe alphitoides and plant-feeding insect Tuberculatus annulatus, we conducted an active field heating experiment using grafts of five oak genotypes Quercus robur. We found that experimental warming generally advanced oak bud burst in spring and delayed leaf senescence in autumn, while additional variation was explained by tree genotype and warming-by-genotype interactions. Warming or tree genotype did not affect disease levels at the beginning of the season, but shaped both disease levels and aphid density during the latter part of the season. Overall, our findings demonstrate that elevated temperature and genetic variation affect spring and autumn phenology, as well as the seasonal dynamics of higher trophic levels. Such effects may be either direct (i.e. temperature affecting tree phenology and attack independently) or indirect (as due to climate-induced changes in plant traits or the synchrony between trees and their attackers). To achieve a predictive understanding of the ecological responses and potential evolutionary changes of natural food webs in response to climate warming, we should merge the frameworks of global warming and community genetics.
|
|
| 2. |
- Moreira, Xoaquín, et al.
(författare)
-
Impacts of urbanization on insect herbivory and plant defences in oak trees
- 2019
-
Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 128:1, s. 113-123
-
Tidskriftsartikel (refereegranskat)abstract
- Systematic comparisons of species interactions in urban versus rural environments can improve our understanding of shifts in ecological processes due to urbanization. However, such studies are relatively uncommon and the mechanisms driving urbanization effects on species interactions (e.g. between plants and insect herbivores) remain elusive. Here we investigated the effects of urbanization on leaf herbivory by insect chewers and miners associated with the English oak Quercus robur by sampling trees in rural and urban areas throughout most of the latitudinal distribution of this species. In performing these comparisons, we also controlled for the size of the urban areas (18 cities) and gathered data on CO2 emissions. In addition, we assessed whether urbanization affected leaf chemical defences (phenolic compounds) and nutritional traits (phosphorus and nitrogen), and whether such changes correlated with herbivory levels. Urbanization significantly reduced leaf chewer damage but did not affect leaf miners. In addition, we found that leaves from urban locations had lower levels of chemical defences (condensed and hydrolysable tannins) and higher levels of nutrients (nitrogen and phosphorus) compared to leaves in rural locations. The magnitude of urbanization effects on herbivory and leaf defences was not contingent upon city size. Importantly, while the effects of urbanization on chemical defences were associated with CO2 emissions, changes in leaf chewer damage were not associated with either leaf traits or CO2 levels. These results suggest that effects of urbanization on herbivory occur through mechanisms other than changes in the plant traits measured here. Overall, our simultaneous assessment of insect herbivory, plant traits and abiotic correlates advances our understanding of the main drivers of urbanization effects on plant-herbivore interactions.
|
|
| 3. |
- van Dijk, Laura J. A., 1990-, et al.
(författare)
-
Soil microbiomes drive aboveground plant–pathogen–insect interactions
- 2022
-
Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 2022:12
-
Tidskriftsartikel (refereegranskat)abstract
- Plants interact with a large diversity of microbes and insects, both below and above ground. While studies have shown that belowground microbes affect the performance of plants and aboveground organisms, we lack insights into how belowground microbial communities may shape interactions between aboveground pathogens and insects. We investigated how soil microbiomes and aboveground organisms affect plant growth and development, and whether differences in soil microbiomes influence interactions between aboveground organisms. We conducted a growth-chamber experiment with oak seedlings Quercus robur growing in three soils with similar abiotic soil properties but with distinct natural soil microbiomes. Seedlings were subjected to single or dual attack by powdery mildew Erysiphe alphitoides and aphids Tuberculatus annulatus, either in the presence or absence of prior attack by a free-feeding caterpillar Phalera bucephala. Soil microbiomes were associated with differences in seedling height, and seedlings with multiple aboveground organisms had more but smaller leaves than healthy seedlings. The soil microbiome affected the severity of powdery mildew infection, and mediated the impact of co-occurring aboveground organisms on aphid population size. Our study highlights that plant performance is affected by natural soil microbiomes as well as aboveground organisms, and that natural soil microbiomes can affect interactions between pathogens and insects. These findings are important to understand species interactions in natural systems, as well as for practical applications, such as manipulation of soil microbiomes to manage agricultural pests and diseases.
|
|
| 4. |
- Wickander, Niklas J., et al.
(författare)
-
Ecological and evolutionary responses of an arctic plant to variation in microclimate and soil
- 2021
-
Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 130:2, s. 211-218
-
Tidskriftsartikel (refereegranskat)abstract
- The arctic and alpine regions are predicted to experience some of the highest rates of climate change, and the arctic vegetation is expected to be especially sensitive to such changes. Understanding the ecological and evolutionary responses of arctic plant species to changes in climate is therefore a key objective. Geothermal areas, where natural temperature gradients occur over small spatial scales, and without many of the confounding environmental factors present in latitudinal and other gradient studies, provide a natural experimental setting in which to examine the response of arctic-alpine plants to increasing temperatures. To test the ecological and evolutionary response of the circumpolar alpine bistort Persicaria vivipara to temperature, we collected plant material and soil from areas with low, intermediate and high soil temperatures and grew them at three different temperatures in a three-factorial growth chamber experiment. At higher experimental soil temperatures, sprouting was earlier and plants had more leaves. Sprouting was earlier in soil originating from intermediate temperature and plants had more leaves when grown in soil originating from low temperatures. We did not find evidence of local adaptation or genetic variation in reaction norms among plants originating from areas with low, intermediate and high soil temperature. Our findings suggest that the alpine bistort has a strong plastic response to warming, but that differences in soil temperature have not resulted in genetic differentiation. The lack of an observed evolutionary response may, for example, be due to the absence of temperature-mediated selection on P. vivipara, the low rate of sexual recombination, or high levels of gene flow balancing differences in selection. When placed within the context of other studies, we conclude that arctic-alpine plant species often show strong plastic responses to spring warming, while evidence of evolutionary responses varies among species.
|
|
