Silva Tarouca Research Institute for Landscape and Ornamental Gardening

Probably the rarest pine species in the world, Pinus rarissima from central Vietnam, is described, illustrated and named, and its present-day distribution is characterized in detail. We classify it as a member of series Dalatenses (of the genus Pinus subgenus Strobus section Quinquefoliae subsection Strobus). It closely resembles P. dalatensis from the same series but also shares some features with P. anemophila from P. series Chylae subseries Wangianae. A thorough morphological comparison of the new pine species with similar taxa is presented, along with a key to the determination of pines of section Quinquefoliae occurring in Vietnam, Laos and southern China.

Human activities significantly influence landscapes, altering natural habitats and ecosystem services. This study examines the relationship between human impacts, measured by the hemeroby index and coefficient of anthropogenic impact (CAI´), and the presence of natural habitats in the Czech Republic. Using CORINE land cover data and natural habitat mapping, we analysed national and regional scales to assess the effectiveness of these indicators in reflecting environmental changes. Compared with the simple anthropogenic impact coefficient (CAI´), the hemeroby index, which accounts for both the quantity and quality of ecosystems, provides more detailed insights. At the national level, both indices had an equally close relationship with the proportion of natural habitats, but at the regional level, the results for the hemeroby index were better. Our findings indicate a strong negative correlation between human impacts and the proportion of natural habitats, emphasizing the importance of refined indicators for environmental monitoring and policy-making. The advantage of both indices is that they could be easily calculated from satellite images and/or land cover data. Therefore, they could be used worldwide.

ContextHistorical land use is thought to have influenced plant community diversity, composition and function through the local persistence of taxa that reflect ecological conditions of the past.ObjectivesWe tested for the effects of historical land use on contemporary plant species richness, composition, and ecological preferences in the grassland vegetation of Central Europe.MethodsWe analyzed 6975 vegetation plots sampled between 1946 and 2021 in dry, mesic, and wet grasslands in the borderland between Austria, the Czech Republic, and Slovakia. Using 1819–1853 military maps, we assigned each plot to a historical land-use category (arable land, forest, grassland, settlement, permanent crop, and water body). We modeled the response of species richness, composition, and plant ecological preferences to the historical land use including contemporary covariates.ResultsNineteenth-century land use explained little overall variation in species richness and composition, whereas more variation was explained by contemporary environmental conditions. However, we found that ecological preferences of some species were associated with specific historical land uses. Specifically, species more frequently occurring in historically forested grasslands showed lower light and disturbance frequency indicator values, while those associated with former settlements displayed higher disturbance severity indicator values.ConclusionsWe conclude that signatures of specific land-use conversions, including the restoration of grasslands in human-impacted areas, may still be detectable in grasslands even 200 years into the future. However, while local historical land use influences the occurrence of some species based on their ecological preferences, these effects do not significantly influence community species richness and total composition.

The genus Salix, comprising some 400–500 species, is important in various alluvial or wet habitats of the northern hemisphere. It is a promising crop for applications such as biomass production, biofuels, or environmental projects. Clear species delimitation is crucial in ecology, biotechnology, and horticulture. DArTseq markers, a genome-wide technique, were tested for species and hybrid identification. A total of 179 willow samples were analysed, including six species of Salix subgen. Salix and four species of Salix subgen. Vetrix, including those used in biomass crop production, representing important European taxa. Identification of species-specific markers, clustering analyses (principal coordinate analysis, neighbor-joining) and Bayesian methods (Structure) unambiguously identified putative hybrids. In addition to demonstrating the high efficiency of DArT-seq markers in identifying willow hybrids, we also opened-up new questions about hybridisation processes and systematics. We detected unidirectional hybridisation between S. alba and S. fragilis, forming backcross hybrids, and we rejected the hypothesis that S. fragilis does not occur naturally in Europe. Further, the isolated position of Salix triandra within the genus was confirmed.

Traditional agroforestry on agricultural land was common in the past in Central Europe. However, much less is known about agroforestry on forested land, especially because it was often banned by forestry authorities during the 20th century. We used data from the so-called stable cadastre to map the occurrence of agroforestry uses (litter raking, hay cutting and forest grazing) on forested land in the mid-19th century in Moravia (eastern part of the Czech Republic, ca. 27,000 km2) in high spatial resolution. We combined machine learning algorithms and logistic models to reveal which environmental, land use and forest management factors could be linked to the occurrence of individual agroforestry uses. Results showed that agroforestry on forested land was very common in the 19th century: only 9.2% of townships with forests had no agroforestry uses. The distribution of agroforestry uses was clearly connected to environmental factors and to the availability of agricultural products that agroforestry uses were meant to supplement (e.g. hay cutting in forests was the most common in townships with large forests and few grasslands). However, the ubiquity of some uses (especially litter raking) made it more difficult to arrive at straightforward conclusions. In addition, we discussed the limitations inherent in the stable cadastre and how these might influence the interpretation of the results.

Knowledge of the quantity of woody biomass of poplar short-rotation coppice (SRC) on agricultural land is a basic tool for management decisions like rotation length, volume production and the financial balance sheet of economic activities. The expansion of SRC requires a fast, reliable, easily applicable and cheap method for estimating the biomass yield, but existing methods are based on labour-demanding and lengthy measurements of all shoots per tree. The objective of this study was to verify a novel rapid biomass estimation method that uses averaged attributes of only a few largest shoots as a predictor variable for woody biomass in a poplar SRC, hybrid clone J-105 (Populus nigra × P. maximowiczii). Using data from 39 sample stumps with 187 shoots in total, we modelled shoot biomass as a function of an increasing number of shoots in interaction with different shoot parameters at two poplar SRC plantations. Results showed that the DBH of only three of the largest shoots per stump proved to be accurate estimators of the total shoot biomass of the individual stump. Comparison of biomass estimates at the stand level with a real amount of biomass indicated differences between 6-14%, depending on the site.