Increased Resistance of Bt Aspens to Phratora vitellinae (Coleoptera) Leads to Increased Plant Growth under Experimental Conditions

One main aim with genetic modification (GM) of trees is to produce plants that are resistant to various types of pests. The effectiveness of GM-introduced toxins against specific pest species on trees has been shown in the laboratory. However, few attempts have been made to determine if the production of these toxins and reduced herbivory will translate into increased tree productivity. We established an experiment with two lines of potted aspens (Populus tremula×Populus tremuloides) which express Bt (Bacillus thuringiensis) toxins and the isogenic wildtype (Wt) in the lab. The goal was to explore how experimentally controlled levels of a targeted leaf beetle Phratora vitellinae (Coleoptera; Chrysomelidae) influenced leaf damage severity, leaf beetle performance and the growth of aspen. Four patterns emerged. Firstly, we found clear evidence that Bt toxins reduce leaf damage. The damage on the Bt lines was significantly lower than for the Wt line in high and low herbivory treatment, respectively. Secondly, Bt toxins had a significant negative effect on leaf beetle survival. Thirdly, the significant decrease in height of the Wt line with increasing herbivory and the relative increase in height of one of the Bt lines compared with the Wt line in the presence of herbivores suggest that this also might translate into increased biomass production of Bt trees. This realized benefit was context-dependent and is likely to be manifested only if herbivore pressure is sufficiently high. However, these herbivore induced patterns did not translate into significant affect on biomass, instead one Bt line overall produced less biomass than the Wt. Fourthly, compiled results suggest that the growth reduction in one Bt line as indicated here is likely due to events in the transformation process and that a hypothesized cost of producing Bt toxins is of subordinate significance

Data from: The extended consequences of genetic conductivity: mating distance affects community phenotypes in Norway spruce

Anthropogenic landscape level alterations such as habitat fragmentation and long distance translocation of genetic material are currently altering the genetic connectivity and structure of forest tree populations globally. As the susceptibility of individual trees to dependent organisms is often genetically determined, it is possible that these genetic changes may extend beyond individuals to affect associated communities. To test this, we examined how variation in crossing distance among the progeny of 18 controlled crosses of Norway spruce (Picea abies) populations occurring across central Sweden affected chemical defense, and subsequently, a small community of galling Adelges aphids infecting planted trees at two common garden trails. Although crossing distance did not influence growth, vitality nor reproduction in the studied population, it did influence the expression of one candidate defensive chemical compound, Apigenin, which was found in higher concentrations within outcrossed trees. We also show that this variation in apigenin induced by crossing distance correlated with susceptibility to one member of the galling community but not the other. Furthermore, the effect of crossing distance on galling communities and the general susceptibility of Norway spruce to infection also varied with environment. Specifically, in the more benign environment inbred trees suffered greater gall infection than outcrossed trees, which is contrary to general predictions that the effects of inbreeding should be more pronounced in harsher environments. These findings suggest that the effects of variation in crossing distance in forest trees can extend beyond the individual to influence whole communities

Popular Cultural Keystone Species are also understudied — the case of camphor tree (Dryobalanops aromatica)

Along with landscape degradation and loss of biodiversity there is also a co-occurring loss of cultural and linguistic diversity. When species become rare, there is a corresponding loss of cultural practices and linguistic elements associated with that species. Although cultural assessments of tree species can help in identifying Cultural Keystone Species (CKS) and be used to enhance the cultural relevance of conservation actions, such information is typically lacking for endangered species were the cultural connections may have been lost. Here, we review historic written accounts to assess the cultural status of the critically endangered camphor tree, Dryobalanops aromatica, native to Southeast Asia which is recognized for its camphor and crystals forming in the wood. We found that despite centuries of use, the importance of the tree for specific cultures has not been fully understood. Published literature indicate that it could be a CKS to multiple communities. The tree was once culturally significant for many cultures in its native range and beyond, but contemporary data is lacking, especially with respect to persistence and memory of use in relation to cultural change. By virtue of being a culturally recognized tree species, as well as having a distinct ecological role within its natural distribution, we propose D. aromatica as a flagship species for conservation and restoration of the habitat it defines. Our review highlights the usability of historic accounts as starting points for identifying CKS and effective conservation of biocultural diversity, especially concerning endangered species. We propose that future research should pay attention to inter and intra-community dynamics of local knowledge on the species, and causes and consequences of varying cultural importance across temporal and spatial scales

Gall and chemistry

Data on gall infection on, and chemical composition of different Norway spruce families growing in two common gardens in Swede

Data from: Trade-offs in the multi-use potential of managed boreal forests

1. Implementing multi-use forest management to account for both commercial and non-commercial ecosystem services is gaining increased global recognition. Despite its spatial extent, and great economic and ecological values, few studies have evaluated the boreal forest and its management to assess the potential for simultaneous delivery of a suite of ecosystem services. 2. Using data from a Swedish long-term experiment this study explores how biodiversity of the ground vegetation and potential delivery of multiple ecosystem services (timber production, carbon (C) storage and non-timber forest products) are influenced by two common silvicultural practices (thinning, fertilization and their interaction). 3. Diversity (diversity indices and species richness) of the ground vegetation was higher in thinned than in unthinned forest, something partly explained by six species of lichens that only occurred in thinned forest. In addition, supply of lichens for reindeer forage was three times higher in thinned forest. Fertilization negatively affected the lingonberry shrub (Vaccinium vitis-idaea). Timber production increased with fertilization, but decreased with thinning. The potential for C storage was highest in fertilized forests, which, apart from having the highest timber production, also supported the highest standing tree biomass. 4. The silvicultural practices evaluated induced trade-offs among the ecosystem features studied as thinning increased biodiversity of the ground vegetation, production potential of wild berries and lichens, but reduced timber production and the forest’s potential for C storage. Fertilization, had the opposite effect, promoting the potential for C storage at the expense of biodiversity and the ecosystem services delivered by the ground vegetation. 5. Synthesis and applications. Silvicultural practice had a pronounced effect on the multi-use output, and trade-offs among values were common. Nevertheless, our study demonstrates that silvicultural practices that are currently adopted in Sweden can be used to adjust the multi-use potential output of forests, suggesting that commonly used practices can be applied to maintain, or even increase the multi-use potential of the boreal forest biome, if management objectives are allowed to vary across the landscape. A prerequisite for this is site specific management objectives that clearly determine the desired output

Standing biomass of trees and ground vegetation

Data presented is standing biomass (above- and belowground) of trees (Scots Pine, Pinus sylvestris) and the ground vegetation. Tree biomass data is derived from stem diameter (at 1.3 m) and tree height using Marklund (1988) biomass functions. Aboveground biomass of ground vegetation is derived from biomass harvest of all aboveground parts of the vegetation in subplots. Belowground biomass was estimate based on published ratios (Nordin et a. 1998). Total biomass refers to the combined biomass of tree and ground vegetation. Besides data related to the species the file contain information on site id, latitude of the experimental sites, treatment, time (years) since last thinning operation and latitude (degrees) north of the southernmost site. Treatments were: Thinning (Th), No thinning (NoTh), Nitrogen fertilization (N), Thinning+ nitrogen fertilization (Th+N), and Thinning+N and P fertilization (Th+N+P)

Composition and richness of the ground vegetation

Data presented is based on point-intercept data from field surveys of the ground vegetation. Compositional data is presented for the 10 most abundant species of the ground vegetation. Richness data, diversity indices and their corresponding evenness measures are based on all species. Besides data related to the species the file contain information on site id, latitude of the experimental sites, treatment, time (years) since last thinning operation and latitude (degrees) north of the southernmost site. Treatments were: Thinning (Th), No thinning (NoTh), Nitrogen fertilization (N), Thinning+ nitrogen fertilization (Th+N), and Thinning+N and P fertilization (Th+N+P)

Production potential of non-timber forest products

Dry weight biomass of berry producing dwarf shrubs (V. myrtillus and V. vitis-idaea) and ground living lichens (utilized by reindeers during winter) in five treatments. Lichen data are from sites located in the counties currently utilized as winter grazing areas (site 895 and sites located north of site 895). Treatments were: Thinning (Th), No thinning (NoTh), Nitrogen fertilization (N), thinning+ nitrogen fertilization (Th+N), and Thiining + N and P fertilization (Th+N+P)

Timber production

Data presented is increase in stem growth of Scots Pine (Pinus sylvestris) between repeated measurements of stem diameter. Production is expressed as stem volume increment (m3) per ha over the experimental period. Besides data on timber production the file contain data on site id, latitude of the experimental sites, treatment, time (years) since last thinning operation and latitude (degrees) north of the southernmost site. Treatments were: Thinning (Th), No thinning (NoTh), Nitrogen fertilization (N), Thinning+ nitrogen fertilization (Th+N), and Thinning+N and P fertilization (Th+N+P)