Forest tree species distribution for Europe 2000-2020: mapping potential and realized distributions using spatiotemporal Machine Learning

Paper describes a data-driven framework based on spatio-temporal ensemble machine learning to produce distribution maps for 16 forest tree species (Abies alba Mill., Castanea sativa Mill. , Corylus avellana L., Fagus sylvatica L., Olea europaea L., Picea abies L. H. Karst., Pinus halepensis Mill., Pinus nigra J. F. Arnold, Pinus pinea L., Pinus sylvestris L., Prunus avium L., Quercus cerris L., Quercus ilex L., Quercus robur L., Quercus suber L. and Salix caprea L.) at high spatial resolution (30 m). Tree occurrence data for a total of 3 million of points was used to train different Machine Learning (ML) algorithms: random forest, gradient-boosted trees, generalized linear models, k-nearest neighbors, CART and an artificial neural network. A stack of 585 coarse and high resolution covariates representing spectral reflectance (Landsat bands, spectral indices; time-series of seasonal composites), different biophysical conditions (i.e. temperature, precipitation, elevation, lithology) and biotic competition (other species distribution maps) was used as predictors for realized distributions, while potential distribution was modelled with environmental predictors only. Logloss and computing time were used to select the three best algorithms to train an ensemble model based on stacking with a logistic regressor as a meta-learner for each species. High resolution (30 m) probability and model uncertainty maps of realized distribution were produced for each species using a time window of 4 years for a total of 6 distribution maps per species for the studied period, while for potential distributions only one map per species was produced. Results of spatial cross validation show that Olea europaea and Quercus suber achieved the best performances in both potential and realized distribution, while Pinus sylvestris and Salix caprea achieved the worst. Further analysis shows that fine-resolution models consistently outperformed coarse resolution models (250 m) for realized distribution (average decrease in logloss: +53%). Realized distribution models achieved higher predictive performances than potential distribution ones. Importance of predictor variables differed across species and models, with the green band for summer and the NDWI and NDVI for fall for realized distribution and the diffuse irradiation and precipitation of the driest quarter being the most important and frequent for potential distribution. The ensemble model outperformed or performed as good as the best individual model in all potential species distributions, while for ten species it performed worse than the best individual model in modeling realized distributions. The framework shows how combining continuous and consistent EO time series data with state of the art ML can be used to derive dynamic distribution maps. The produced time-series occurrence predictions can be used to quantify temporal trends and detect potential forest degradation.

Syntaxonomy of secondary communities formed instead of earlier agricultural lands in the middle and south taiga subzones of the European North-East of Russia

We have identified the diversity of secondary communities formed instead of earlier agricultural lands (middle and south taiga subzones of the European North-East of Russia). The work describes 8 associations, 2 subassociations of the classes Papaveretea rhoeadis, Artemisietea vulgaris,Epilobietea angustifolii, Molinio–Arrhenatheretea, Vaccinio–Piceetea. 3 associations (Urtico dioicae–Chamaenerietum angustifolii, Centaureo phrygiae–Dactyletum glomeratae, Deschampsio cespitosae–Salicetum capreae), 1 subassociation (Galeopsietum bifidae galeopsietosum speciosae)were fixed for the first time. We noted a replacement of segetal communities (subass. Galeopsietum bifidae galeopsietosum speciosae) by meadow communities (аss. Centaureo phrygiae–Dactyletum glomeratae) through the domination stage of Cirsium setosum and Elytrigia repens (аss. Cirsio setosi–Elytrigietum repentis). Favorable conditions for development of woody plants (small size of study area, its close position to forest ecosystems, poorly sodded soil) respond for replacement of meadow succession stage by young woody plants towards the second decade of succession. Earlier agricultural lands are an appropriated place for formation of birch forests with a well-developed undergrowth of Salix caprea and herb layer of meadow and forest edge plants (аss. Deschampsio cespitosae–Salicetum capreae). Big-size study areas with a well-formed grass stand are dominated by meadow communities towards the second succession decade even in case of no haying. The highly competitive nitrophytes as Heracleum sosnowskyi, Chamaenerion angustifolium, Anthriscus sylvestris form the following communities as аss. Urtico dioicae–Heracleetum sosnowskyi, аss. Urtico dioicae–Chamaenerietum angustifolii, аss. Symphyto officinalis–Anthriscetum sylvestris. Being highly competitive, these species lead to degradation of first-formed meadow communities.

Metal bioaccumulation, translocation and phytoremediation potential of some woody species at mine tailings

This study aimed to determine the concentrations of ten metals (Mn, Ni, Ca, Mg, Fe, Zn, Cr, Pb, Cd, Cu) in the soil at depths of 10 and 20 cm and selected plant species (Populus nigra L., Fraxinus ornus L., Salix alba L., Salix caprea L.), as well as to assess the ability of these plants of metal bioaccumulation, translocation and phytoremediation on the location of the mine pit and flotation tailings of the selected mine (in the center of the Republic of Serbia). The concentrations of Pb and Cu in the investigated soil at a depth of 10 cm were above remediation values stated in the regulations of the Republic of Serbia. At the same time, the concentration of Cd, Cr, Pb and Cu was above the limit values in both of the examined soil depths, while Ni in the soil at a depth of 10 cm was above the limit value determined in the Directives of the European Union. The species F. ornus shows the ability to phytoextract Ca, species P. nigra Zn, Ca and Cd, while both Salix species have the capacity to phytoextract Zn and Ca. The results showed that species S. alba is an efficient bioaccumulator of Mn, Fe, Cr, Pb, Zn and Ca, S. caprea of Fe, Cu, Cr, Mg and Pb, and P. nigra of Mn and Cd. The bioaccumulation and translocation of the investigated elements depend on plant species and their organ. The selection of plant species adequate for remediation should take this into account.

Scots Pine (Pinus sylvestrisL.) Undergrowth on the Dumps of the Chrysotile Asbestos Deposit

The studies were carried out on the dumps of overburden rocks and tailings of poor ores of the chrysotile asbestos deposit. According to the scheme of forest site zoning, the studying area belongs to the pre-forest steppe district of pine and birch forests of the Zabaikal’ye plain province of the West Siberian plain forest site area. The survey sites were laid out on the terraces of the dump along the running lines. Undergrowth was counted at each survey site. It was classified by viability, size (small, medium, large), and life form (tree, bush, scrub). The provision with undergrowth of the indicated type of disturbed soils was defined and recommendations for measures aimed at accelerating the process of reforestation were given. Undergrowth on the dumps is represented by Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth.), aspen (Populus tremula L.), and goat willow (Salix caprea L.). Scots pine and silver birch are the dominant species in the undergrowth composition. Large share of Scots pine of scrub and bush form is the specific feature of the developing young growth. These specimens were found among small- and medium-sized undergrowth. It is the undergrowth of these heights that becomes an annual attrition without passing into the large-sized category. The latter is the main reason for faster conversion of the dumps into forest-covered area, for increasing the share of clay particles in the upper 50 cm thick dump layer, or for coating the dump surface by non-traditional fertilizers, in particular sewage sludge. It was noted that silvicultural trend in the dump reclamation on the chrysotile asbestos deposit is the most preferable. Scots pine should be preferred as the primary species for reclamation planning. For citation: Zaripov Yu.V., Zalesov S.V., Zalesova E.S., Popov A.S., Platonov E.P., Starodubtseva N.I. Scots Pine (Pinus sylvestris L.) Undergrowth on the Dumps of the Chrysotile Asbestos Deposit. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 22–33. DOI: 10.37482/0536-1036-2021-5-22-33

Green Veterinary Pharmacology Applied to Parasite Control: Evaluation of Punica granatum, Artemisia campestris, Salix caprea Aqueous Macerates against Gastrointestinal Nematodes of Sheep

Resistance to anthelmintic drugs in gastrointestinal nematodes (GIN) of sheep is of high concern for livestock production worldwide. In Calabria (southern Italy), many plants have been used in ethnoveterinary medicine for parasite control in small ruminants. Here, we present an in vivo evaluation of anthelmintic efficacy of three plant extracts. The first was based on bark and leaves of Salix caprea, the second and the third were based on the whole plant Artemisia campestris and whole fruit (seeds and peel) of Punica granatum, respectively. Anthelmintic efficacy was evaluated according to the fecal egg count reduction test (FECRT) performed with the FLOTAC technique. The results showed a significant anthelmintic effect of Punica granatum macerate (50%), a low effectiveness of the Artemisia campestris macerate (20%), and a complete ineffectiveness of Salix caprea macerate (0.1%). With these outcomes, we report a P. granatum-based remedy reducing 50% GIN egg output. This result was obtained without using any synthetic drug, paving the way for the employment of green veterinary pharmacology (GVP) as a complementary and sustainable method to reduce the use of chemicals and to counteract anthelmintic resistance.

Capronia chlorospora. [Descriptions of Fungi and Bacteria].

A description is provided for Capronia chlorospora, found on rotten branch of Salix caprea. Some information on its morphological characteristics, associated organisms and substrata, dispersal and transmission, habitats and conservation status is given, along with details of its geographical distribution (Europe (Czech Republic, Denmark, France, Norway, Spain, Sweden), Switzerland, UK, North America (Canada, Prince Edward Island), USA (Arizona, Massachusetts, New Jersey, Ohio, Vermont), South America (Argentina)).

Exploitative Competition between Mountain Hare and Moose—Qualitative Effects on Hare Winter Forage?

Mountain hares (Lepus timidus) in Scandinavia are classified as Near Threatened in the Norwegian and Swedish Redlists. This is due to a possible population decline witnessed during the last decades in Scandinavia. Competition between large herbivores and mountain hares is one of several hypotheses that has been put forward to explain this decline. In a cafeteria trial we investigate the effects of previous moose (Alces alces) winter browsing on the food selection (i.e., biomass consumed, bites per minute and bitediameter) of downy birch (Betula pubescens) and goat willow (Salix caprea) by captive mountain hares. We find that mountain hares do not differentiate among previous browsing levels of downy birch, but have larger bite diameters of goat willow earlier browsed by moose, compared to non-browsed plants. Thus, effects of moose on mountain hare winter food quality seem to be limited. We highlight the need for studies focusing on (1) qualitative effects of moose browsing using wild mountain hares in a natural experimental design, and (2) quantitative effects of moose browsing on available mountain hare forage at a landscape scale during winter.

Discrimination of Salix caprea, Salix gracilistyla, and Their Interspecific Hybrid Using Vegetative Characteristics and Partial Least Squares Discriminant Analysis

Identifying the morphological characteristics that distinguish plant varieties is an important issue for plant breeders and researchers. The objective of the present study was to create a partial least squares discrimination analysis (PLS-DA) model with morphological characteristics for species discrimination and to select the characteristics most important for species discrimination. Data for 27 vegetative characteristics were obtained from Salix caprea and Salix gracilistyla, and their interspecific hybrid (S. caprea × S. gracilistyla), and used for PLS-DA. According to this analysis, seven of the 27 characteristics were identified as those that most influenced species discrimination, and the PLS-DA model with these seven characteristics had a classification accuracy of 86% to 100%. The classification performance of this model was not significantly different from that of the model with all 27 characteristics (full model). Therefore, these results indicated that the three species can be relatively well distinguished by the seven characteristics extracted by PLS-DA. In addition, the selected characteristics can be used to select cross-breeding parents in subsequent breeding programs and to test the distinction, uniformity, and stability (DUS test) of the hybrid variety. From this perspective, PLS-DA is thought to be a useful methodology for classifying new plant varieties and providing information for breeding.

Effect of Soil Degradation and Remediation in Technogenic Barrens on the Uptake of Nutrients and Heavy Metals by Plants in the Kola Subarctic

To assess the state of plants and their response to changes in soil properties, the elemental composition of leaves of widespread and pollution-tolerant species Betula pubescens Ehrh. and Salix caprea L. has been studied near the nonferrous metallurgy enterprises in the Kola Peninsula. The content of nutrients and heavy metals in the leaves of undergrowth on technogenic barrens and remediation sites differing in remediation technologies has been analyzed. According to the results of leaf diagnostics, both species under barren conditions are characterized by a noticeable deficiency of K, Ca, P, and, especially, Mn and Zn. The leaves of both species accumulate Ni, Cu, Co, As, Cr, Fe, Al, Pb, V, and S. Willow leaves contain more Cd, Co, Cr, Ni, Cu, Al, Fe, As, S, Ca, K and less Mn than birch leaves. Chemophytostabilization has little effect, and the covering of contaminated soils with a constructed fertile layer leads to the enrichment of birch and willow leaves with Ca, K, and P. Under conditions of continuing atmospheric emissions and gradual accumulation of bioavailable heavy metals in soils after the remediation, the accumulation of metals in leaves is largely determined by the distance from the pollution source, reflecting the possibility of both root and foliar uptake. The concentrations of Ni and Cu in leaves in 2018 did not decrease compared to 2011. The low, albeit varying, ratios of the contents of heavy metals in undergrowth leaves and in the soil and weak correlation of heavy metal contents in these media indicated that B. pubescens and S. caprea retain their ability to regulate their chemical composition even under extreme conditions of technogenic barrens. At the same time, supporting the protective capabilities of plants via optimizing mineral nutrition and soil acidity in combination with a reduction in atmospheric pollution is a prerequisite for efficient remediation of technogenic territories in the Far North.

Three options are better than two: compensatory nature of different pollination modes in Salix caprea L.

Mixed pollination systems have been reported for many angiosperms. Here, we report on a dioecious willow, Salix caprea L., which employs three pollination modes, namely pollination by wind, nocturnal moths, and diurnal bees. In four field populations of S. caprea in Germany, we addressed the following questions: (a) How are the pollination modes affected by local mate availability? (b) What is the contribution of each pollination mode to seed set? (c) How does flower opening time affect pollination? We compared seed set among seven pollination treatments (wind pollination, diurnal pollination, nocturnal pollination, natural pollination, apomictic reproduction, daytime/night-time artificial pollination). Pollen limitation was observed across populations. On the other hand, limitations in mate availability affected the pollination modes differently. Insect pollination outperformed wind pollination in situations where nearby males were few or all positioned in the same direction from the females. The contribution of nocturnal moths was lower than that of the other pollen vectors. However, moth pollination worked complementarily with bee pollination in compensating for the lack of wind pollination. Furthermore, we found that the onset of flower anthesis peaked at sunset, and that cold night temperatures had no negative effect on seed set or pollen viability. Thus, nocturnal anthesis and prior pollination by moths may minimize male fitness loss due to pollen collection and grooming by bees. We suggest that S. caprea maximizes its fitness by combining multiple pollination modes that work in different environmental conditions, while optimizing the anthesis so that more pollen would be delivered to stigmas.