Metabarcoding is emerging as an alternative to morphological methods in noninvasive carnivore diet analysis based on scats. A number of metabarcoding markers have been developed but their comparative performance to recover DNA from scats remains mostly untested. We tested three markers covering a wide taxonomic range of prey items and compared them with the results of a morphological analysis. Morphological and genetic methods performed comparably regarding the identity of detected prey species, but the number of identified species varied strongly between markers. Only one, 12S-V5, amplified successfully in all samples and proved to be robust and reliable when working with the highly degraded DNA obtained from scats.

Genetic diversity is considered to be a prerequisite for adaptation and adaptability as it is a key element of biological diversity. However, the monitoring of genetic diversity has tended to be ignored in biodiversity monitoring. We report a comprehensive genetic monitoring effort in two dominant forest tree species, which was started with a baseline survey in 12 European beech populations and 10 Norway spruce populations in Germany. The standardized experimental design is based on collecting samples of at least 250 adult trees, and 400 natural regeneration and 400 seed samples and their genotyping with 15–16 high-resolution SSR markers. In addition to commonly used mean values across the markers to quantify genetic diversity, we placed special emphasis on various marker-based, pedigree-based and demographic models for estimating the contemporary effective population size N e of the different generations. In both beech and spruce, no variation in genetic diversity with mean values across markers was detectable between the studied stands and between age cohorts. We detected that stable allelic diversity in progeny generations is ensured by sufficient gene flow from surrounding forests. However, estimates of effective population size show marked differentiation among populations and among age cohorts. Natural regeneration samples appear to converge on the parent generation, while seed samples show a clear bottleneck effect. The N e parameter can be used to derive conclusions for sustainable natural regeneration management in forest stands and for seed stand approvals including adequate seed collections for appropriate artificial regenerations.The sibship frequency-based method for N e estimates is presented as much more robust than the widely used LD estimates, which often fail for samples with too weak relatedness. Despite the distinct kinship structure in our monitoring plots, the contemporary effective population size proves to be an essential parameter for assessing the integrity of the reproductive system.

Adult individuals and seeds of two mixed stands of coastal and interior Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) were analysed for genetic differentiation between the two varieties and evidence of intervarietal pollination. Clear genetic discrimination between the two varieties was observed based on multilocus evaluation of nine microsatellite markers using other Douglas-fir stands of known variety composition for comparison. Analysis of pollination distances showed that 80% of pollinations took place within a distance of about 44–55 m. Analysis of stand structure showed clearly separated areas of mainly coastal or interior Douglas-fir within both stands. Together with short pollination distances this led to an apparent dominance of intravarietal pollinations. However, analysis of pollination partners of trees growing near the border of the variety specific areas, does not indicate the existence of reproductive barriers between trees of the two varieties growing in mixed stands. Therefore, commercial seed harvesting in mixed stands should be avoided if the production of seed lots of pure coastal or interior Douglas-fir is intended.

In Germany, Douglas fir ( Pseudotsuga menziesii Franco) is seen as a valuable species for future cultivation in times of climate change. Local seed production in seed stands and seed orchards may secure that local adaptation is transferred to the next generation, but small population sizes could lower genetic diversity and thus future adaptability. Here we analyse the transfer of genetic diversity from parent to offspring generation in four older German seed orchards. We detected low pollen contamination rates due to high levels of spatial isolation. Even with a relatively low number of 40 clones, seed orchard design with randomized and repeated planting of clones led to low selfing rates, and despite uneven parental contributions, the number of successful parents and the level of genetic intermixture were high enough to allow the transfer of an adequate part of the genetic diversity to the next generation. Larger numbers, however, might be needed to reliably conserve the entire genetic diversity over succeeding generations. Conclusions on the establishment of future seed orchards and regarding areas requiring further research are drawn at the end of the paper.

Abstract Oaks (Quercus) are major components of temperate forest ecosystems in the Northern Hemisphere where they form intermediate or climax communities. Sessile oak (Quercus petraea) forests represent the climax vegetation in eastern Germany and western Poland. Here, sessile oak forms pure stands or occurs intermixed with Scots Pine (Pinus sylvestris). A large body of research is available on gene flow, reproduction dynamics, and genetic structure in fragmented landscapes and mixed populations. At the same time, our knowledge regarding large, contiguous, and monospecific populations is considerably less well developed. Our study is an attempt to further develop our understanding of the reproduction ecology of sessile oak as an ecologically and economically important forest tree by analyzing mating patterns and genetic structure within adult trees and seedlings originating from one or two reproduction events in an extensive, naturally regenerating sessile oak forest. We detected positive spatial genetic structure up to 30 meters between adult trees and up to 40 meters between seedlings. Seed dispersal distances averaged 8.4 meters. Pollen dispersal distances averaged 22.6 meters. In both cases, the largest proportion of the dispersal occurred over short distances. Dispersal over longer distances was more common for pollen but also appeared regularly for seeds. The reproductive success of individual trees was highly skewed. Only 41 percent of all adult trees produced any offspring while the majority did not participate in reproduction. Among those trees that contributed to the analyzed seedling sample, 80 percent contributed 1–3 gametes. Only 20 percent of all parent trees contributed four or more gametes. However, these relatively few most fertile trees contributed 51 percent of all gametes within the seedling sample. Vitality and growth differed significantly between reproducing and nonreproducing adult trees with reproducing trees being more vital and vigorous than nonreproducing individuals. Our study demonstrates that extensive, apparently homogenous oak forests are far from uniform on the genetic level. On the contrary, they form highly complex mosaics of remarkably small local neighborhoods. This counterbalances the levelling effect of long‐distance dispersal and may increase the species’ adaptive potential. Incorporating these dynamics in the management, conservation, and restoration of oak forests can support the conservation of forest genetic diversity and assist those forests in coping with environmental change.

Aus den Untersuchungen zu den genetischen Konsequenzen einer selektiven Durchforstung mit starker Reduktion der Populationsgrose und -dichte in einem Buchenerntebestand (s. S.35 in diesem Heft) ergeben sich Empfehlungen fur die Bewirtschaftung von Buchensaatgutbestanden.

Experten am Thunen-Institut fur Forstgenetik haben sich mit der Frage befasst, inwieweit die derzeit ubliche Bewirtschaftung von Saatgutbestanden der Rotbuche den Anforderungen an qualitativ und genetisch hochwertigem Saatgut gerecht wird. Vorgestellt werden wissenschaftliche Ergebnisse aus dem Projekt.

Douglas-fir (Pseudotsuga menziesii), native to western North America, was introduced to Europe about 150 years ago. Nowadays it represents the most frequent non-native forest tree species in Germany, covering about 2% of the forest area. While seeds were initially imported from its natural distribution range, the German seed market is now mainly supplied with seeds from local stands. In this study we examined four representative, different sized artificial Douglas-fir stands. We used microsatellite markers to characterise adults and offspring by analysing the genetic diversity and mating system. We detected a negative correlation of population size and genetic diversity. The loss of alleles with descending population sizes cannot be compensated by pollen from outside of the stand. The results showed an increased selfing rate (1-13%) correlated with increased inbreeding effects like a high percentage of empty seeds. Diversity parameters calculated as averages across the analysed loci should always be completed with the calculation of effective population sizes considering sibship structures based on multilocus genotypes. The combined approaches are an improved basis for drawing practical conclusions. We recommend that the current regulations for forest reproductive material should be adapted. For wind-pollinated stand-forming tree species a minimum number of 100 adult trees should be required to form approved seed stands in the category "Selected".

Many plant species reproduce by cloning if environmental conditions are unfavorable for sexual reproduction. To test the alternative hypotheses, whether cloning is an "exit strategy" or caused by selection, clonal growth in white spruce (Picea glauca (Moench) Voss) was investigated in three stands in Alaska, each consisting of a core (closed forest) plot and an edge (tree-line) plot. In total, 2571 trees were mapped and genotyped with 11 single sequence repeat (SSR) markers. The proportion of clonal trees follows a moisture gradient and was lowest in the dry Interior basin (4.5%), followed by the sites at the Alaska Range (9.0%) and the Brooks Range (21.7%). At the two latter sites, clonal growth was more frequent in the edge plot. A comparison among 960 aged trees revealed that clonal growth becomes more likely with increasing age and continues over the life span of a tree. Genetic data do not indicate any genetic predisposition for cloning. Clonal growth in white spruce most likely takes place via layering and depends on environmental conditions. Because performance of the trees, and therefore likely plant reproductive success, is lower in plots with a high proportion of clones, selection for clonal growth seems to be highly unlikely.

Northern and elevational treelines are classic sites for dendroclimatological studies. At these marginal sites only one climate parameter is usually considered growth limiting and trees from these sites are therefore used to reconstruct that parameter back in time. Marginal sites are also those sites within a species range, where clonal reproduction is most frequent. Clonal growth can ensure plant species survival and growth under stressful conditions or if the environmental conditions do not allow sexual reproduction, e.g. by layering, by stems resprouting after damage, or through the exchange of resources between different clone ramets (“stems”). We literally stumbled across clonal and non-clonal growth forms of White spruce growing intermingled with each other at two Alaskan treeline sites. The two growth forms could not be distinguished a priori in the field. After sampling and detection of clones we thus asked whether clonal ramets and non-clonally grown trees (singletons) showed similar growth patterns. Clones were identified by identical multilocus genotypes in a SSR microsatellite genotyping analysis and radial growth was analyzed using traditional tree ring width methods High-frequency growth patterns were very similar between singletons and clonal ramets in Alaskan treeline White spruce, thus posing no problem in including both reproductive strategies in a classic dendroclimatological investigation.

Um die Aussicht auf eine Ernte abzuschatzen, wird in Erntebestanden ublicherweise eine Abschatzung der Blute und der Fruktifikation vom Boden aus vorgenommen. Auch mithilfe von Fernglasern bleibt diese Methode schwierig: der Blick ins Gegenlicht durch die Kronen hindurch macht eine genaue Abschatzung von Blute und Fruchtansatz problematisch. Abhilfe kann der Einsatz von Kameradrohnen schaffen, die die Baumkronen von oben fotografieren.

Die Qualitatsanforderungen an forstliches Vermehrungsgut sind hoch. Neben der Angepasstheit an die klimatischen Bedingungen des Anbaugebiets soll es Pflanzen hoher Qualitat hervorbringen und Anpassungsfahigkeit an sich wandelnde Klimabedingungen aufweisen. Um diese Anforderungen zu erfullen, wird Saatgut in Deutschland in zugelassenen Erntebestanden oder Samenplantagen erzeugt. In Erntebestanden kann die gezielte Beerntung besonders hochwertiger Baume genutzt werden, um die genetische Qualitat des produzierten Saatgutes zu maximieren. Anhand eines Erntebestands der Rot-Buche wurde untersucht, ob sich durch eine einzelbaumweise Ernte von Bucheckern am Boden in geschlossenen Bestanden gezielt Saatgut bestimmter Baume gewinnen lasst und inwieweit sich die Ausbeute an Saatgut erwunschter Erntebaume durch deren Freistellung erhoht. Die genetische Untersuchung von gezielt gesammelten Bucheckern auf unter qualitativ hochwertigen Baumen ausgelegten Netzen ergab, dass bei groser Streuung im Mittel 45 % der geernteten Bucheckern vom Zielbaum stammen. Ein Anteil von 55 % stellt Saatgut anderer Baume dar, ein Anteil von durchschnittlich 12 % der geernteten Bucheckern stammt vom jeweils nachstbenachbarten Baum minderer Qualitat. Eine Freistellung von Erntebaumen erhoht die Ausbeute an Zielsaatgut erheblich. Die Saatgutreinheit liegt hier bei durchschnittlich 74 %. Die Entfernung zwischen den Baumen im Untersuchungsbestand betragt im Mittel 11,3 m im geschlossenen und 21,6 m im freigestellten Bestand. Die Ergebnisse zeigen, dass diese auch Distanzen von relativ schweren Samen wie Bucheckern regelmasig uberwunden werden konnen. Eine gezielte einzelbaumweise Beerntung ist daher im geschlossenen Bestand kaum umsetzbar. In solchen Bestanden wird das geerntete Saatgut immer auch Anteile wenig hochwertiger Baume enthalten, unter Umstanden sogar zu hoheren Anteilen als Samen des eigentlichen Zielbaumes. Die Freistellung bietet sich daher als Moglichkeit an, die Saatgutqualitat in bestehenden Erntebestanden zu erhohen. Aufbauend auf den Ergebnissen soll in weiteren Untersuchungen eine detaillierte Rekonstruktion der Samen- und Pollenausbreitung in geschlossenen und in freigestellten Erntebestanden erfolgen.

Plant-associated mycobiomes in extreme habitats are understudied and poorly understood. We analysed Illumina-generated ITS1 sequences from the needle mycobiome of white spruce (Picea glauca) at the northern treeline in Alaska (USA). Sequences were obtained from the same DNA that was used for tree genotyping. In the present study, fungal metabarcoding and tree microsatellite data were compared for the first time. In general, neighbouring trees shared more fungal taxa with each other than trees growing in further distance. Mycobiomes correlated strongly with phenological host traits and local habitat characteristics contrasting a dense forest stand with an open treeline site. Genetic similarity between trees did not influence fungal composition and no significant correlation existed between needle mycobiome and tree genotype. Our results suggest the pronounced influence of local habitat conditions and phenotypic tree traits on needle-inhabiting fungi. By contrast, the tree genetic identity cannot be benchmarked as a dominant driver for needle-inhabiting mycobiomes, at least not for white spruce in this extreme environment.

In search of decisive factors for the occurrence of corticolous myxomycetes we investigated a plot comprising 380 white spruce trees (Picea glauca) in the Denali National Park and Reserve, Alaska. Moist chambers were prepared from the bark of 260 trees and cultured for 77 d. Occurrence patterns of corticolous myxomycetes were related to tree position and eight environmental variables; among them are diameter at breast height (dbh), tree age and vitality, and bark pH. Tree age and dbh, but not vitality, are highly correlated with each other. Bark pH decreases with increasing diameter of a tree. Only two species of myxomycetes, Leocarpus fragilis (164 records) and Paradiacheopsis solitaria (72) were common. The first species fruits typically on litter; in the study it preferred small trees (low dbh) with a rather high bark pH and high vitality. The second species is known as truly corticolous and prefers thick (usually older) trees with a low pH and a lower vitality. The low and statistically insignificant Cole index for association between the two species (0.047) points to niche separation. For both species mark connection functions indicate a near-random spatial distribution among trees. L. fragilis could effectively colonize small trees (55% of all records occurred on trees below 15 cm dbh). P. solitaria seems to avoid small trees (92% of all records occurred on trees exceeding 15 cm dbh). Our data indicate that the occurrence of corticolous myxomycetes is not limited by dispersal capability but by habitat suitability. (C) 2016 Elsevier Ltd and British Mycological Society. All rights reserved.

This data set contains data about corticolous (bark-inhabiting) myxomycetes from a 100×100m2 plot including ca. 380 trees of Picea glauca (white spruce), of which 260 were large enough that bark could been sampled to prepare moist chamber cultures. At the end of the data set records of myxomycetes from 66 moist chambers prepared with bark of deciduous trees and shrubs, and outermost twiglets of P. glauca are included. These were sampled around the plot for purposes of comparison. A second data set shows measured tree parameters for the 380 trees examined in the plot. Data were used for a statistical analysis to search for environmental factors decisive for the occurrence of corticolous myxomycetes (Schnittler et al., 2016) [1].

This paper introduces a new approach-the Principal Component Gradient Analysis (PCGA)-to detect ecological gradients in time-series populations, i.e. several time-series originating from different individuals of a population. Detection of ecological gradients is of particular importance when dealing with time-series from heterogeneous populations which express differing trends. PCGA makes use of polar coordinates of loadings from the first two axes obtained by principal component analysis (PCA) to define groups of similar trends. Based on the mean inter-series correlation (rbar) the gain of increasing a common underlying signal by PCGA groups is quantified using Monte Carlo Simulations. In terms of validation PCGA is compared to three other existing approaches. Focusing on dendrochronological examples, PCGA is shown to correctly determine population gradients and in particular cases to be advantageous over other considered methods. Furthermore, PCGA groups in each example allowed for enhancing the strength of a common underlying signal and comparably well as hierarchical cluster analysis. Our results indicate that PCGA potentially allows for a better understanding of mechanisms causing time-series population gradients as well as objectively enhancing the performance of climate transfer functions in dendroclimatology. While our examples highlight the relevance of PCGA to the field of dendrochronology, we believe that also other disciplines working with data of comparable structure may benefit from PCGA.

Aus Herkunftsversuchen konnen wertvolle Informationen zu phanotypischen Merkmalsauspragungen und zur Anpassungsfahigkeit von Baumarten im Verbreitungsgebiet und unter verschiedenen Umweltbedingungen gewonnen werden. Das Saatgut fur Herkunftsversuche oder Nachkommenschaftsprufungen sollte dabei fur den jeweiligen Ausgangsbestand reprasentativ sein, um die verschiedenen phanotypischen Merkmale in ihrer typischen Auspragung und Variationsbreite zu erfassen. In dieser Studie wurden Stichproben aus sechs Nachkommenschaften aus einem Buchen-Herkunftsversuch (Fagus sylvatica L.) mit 14 hochvariablen nuklearen Mikrosatellitenmarkern genotypisiert. Die genetische Diversitat erreichte in den Herkunften aus Osterreich, Rumanien und Tschechien hohere Werte, mittlere Werte in den beiden Herkunften aus Deutschland und geringere Werte in der spanischen Herkunft. Zusatzliche Informationen wurden aus den Multilocus-Genotypen der Nachkommen durch die Rekonstruktion von Verwandtschaftsbeziehungen und der Elterngeneration mit einer effizienten Likelihood-Methode gewonnen. Die Software COLONY wurde eingesetzt, um die effektiven Populationsgrosen und die Anzahl der beteiligten Eltern zu ermittelten. Die Rangfolge der sechs Herkunftsnachkommenschaften bei den effektiven Populationsgrosen war hoch reproduzierbar, ebenso die gefundenen Halbgeschwisterfamilien. Die maximale Grose der Halbgeschwisterfamilien befand sich im Bereich zwischen 5 und 15 Individuen in Stichproben von 50 bis 55 je Nachkommenschaft. Aus engen Verwandtschaftsverhaltnissen innerhalb der Nachkommenschaft kann eine kleinere effektive Populationsgrose abgeleitet werden, die trotz groser genetischer Diversitat auftreten kann. Mogliche Ursachen fur die unterschiedliche Reprasentativitat der Prufglieder werden in einer geringen Anzahl Erntebaume oder unausgewogenen Saatgutmengen vermutet.

Fifteen previously published microsatellite primer pairs developed for and tested on Canadian white spruce were screened for amplification and polymorphy in Alaskan populations and tested for their suitability in PCR multiplexing. Eleven loci expressing polymorphisms ranging from 7 to 58 alleles were selected for development and optimization of three multiplex assays. Four natural stands containing a total of 1470 trees were used to characterize the selected loci and demonstrate their applicability for genotyping studies and parentage analysis. These assays can be used for studies focusing on population genetics, parentage analysis, provenance research, or individual genetic fingerprinting. The use of multiplex PCR facilitates large-scale studies by simultaneously enabling high resolution and reducing processing time and per sample cost.