Pine-oak Forest Research Articles

Moss Diversity of a Pine-Oak Forest in Oaxaca, Mexico

The pine-oak forests of Mexico are reservoirs of high biological diversity, largely due to their high richness of vascular flora. However, mosses have received little attention. We studied the floristic composition, diversity, and species richness of the moss community in the pine-oak forests of the Sierra Norte of Oaxaca, Mexico. A comprehensive list of the species occurring in the region was made by reviewing herbarium databases and conducting fieldwork. We analyzed alpha and beta diversity, as well as community structure, based on 60 sampling sites. Our results show the occurrence of 339 species of mosses in the study area, distributed in 168 genera and 52 families. We found high α and β diversity values compared with other vegetation types in Mexico. Our study provides a more detailed portrait of the high moss diversity occurring in the region.

Characterizing the impact of Land-Use/Land-Cover changes on a Temperate Forest using the Markov model

Land-Use/Land-Cover (LULC) change is one of the main factors contributing to ecosystem degradation and to the global climate change. The Markov Chains (MC) model is a widely used technique for the spatio-temporal evaluation of LULC changes, allowing the projection of the landscape variability based on the multidirectional potential of LULC changes. This study assessed the LULC changes in a disturbed temperate forest basin of northern México during the period 1990–2019. In addition, three LULC scenarios, employing the MC model, were projected for 2048. Supervised classification techniques were performed on data from Landsat sensors to generate LULC maps. Results from the Kappa Index showed a precision of 85 and 85.8% for the classifications of 1990 and 2019, respectively. During the evaluated period, degradation and deforestation processes in the basin were the main factors of disturbance, causing the pine-oak forest to show the biggest loss of coverage (190.81 km2). Conversely, open lands showed the biggest increase in its coverage, which indicates anthropogenic activities as the main driver causing changes on the ecosystem. Projections for 2048 indicate processes of degradation and deforestation will continue, expecting increases in coverage for open lands, deciduous forest, and secondary forest. The current and projected conditions of the landscape highlight the importance of the implementation of conservation and restoration strategies, as well as responsible public policies in the study area to mitigate the impacts on these ecosystems.

Seasonal dynamics of Diptera in individual biotopes in the center of the European part of Russia

In a changing climate, phenological observations are gaining new importance. They can tell what changes are taking place in certain environmental conditions. The studies were conducted in 2019 within the territory of the Republic of Mordovia (the center of the European part of Russia). Beer traps (beer as a bait) were used to collect Diptera. The material was collected in the period from April to October in different forest biotopes (pine forest, lime forest, aspen forest, birch forest and oak forest) and the air temperature was recorded at the same time. In total, more than 14.000 specimens of Diptera were recorded. Overall, 29 families were recorded. The largest number of families was observed for birch (23 families) and pine (24 families) forests, the smallest number – in aspen forest (16 families). The families Muscidae, Drosophilidae, Calliphoridae had the largest number of captured individuals (44.5%, 35.2%, 7.6% of the total number of individuals respectively). The highest number of individuals was captured in oak forest. The dynamics of abundance in all biotopes were similar and were characterized by the same number of declines and rises. The first small significant peak in the number of Diptera occurred in the first half of summer. A slight increase in the number of specimenі occurred in mid-June. In the second half of September, there was a gradual increase in the number and the maximum peak was recorded in mid-October, then there was a decline. The autumn increase in the number of Diptera in all five biotopes exceeded the summer peak by several times. This dynamic was typical for most families. However, species from the family Lonchaeidae had the peak in July. For our better understanding of the changes in the seasonal dynamics of the number of Diptera, long-term observations in different climatic zones are needed.

Mixed-Severity Wildfire as a Driver of Vegetation Change in an Arizona Madrean Sky Island System, USA

Fire is a powerful natural disturbance influencing vegetation patterns across landscapes. Recent transitions from mixed-species forests to post-fire shrublands after severe wildfire is an increasingly prevalent phenomenon in pine-oak and conifer forest ecosystems in southwestern North America. However, we know little about how variation in fire severity influences other common forest types in the region. In this study, we evaluated fire-induced changes in woody plant community composition and forest structure in Chiricahua Mountains in southeastern Arizona in the United States that hosts a diverse set of vegetation types. Cluster analysis of the pre-fire vegetation data identified three dominant pre-fire vegetation types including juniper woodland, piñon forest, and pine-oak forest. All vegetation types experienced significant tree mortality across a wide range of size classes and species, from forests to shrublands. The magnitude of change within sample plots varied with fire severity, which was mediated by topography. Significant shifts in dominance away from coniferous obligate seeder trees to resprouting hardwoods and other shrubs occurred across all vegetation types in response to the fire. Regeneration from seed can be episodic, but projected increases in aridity and fire frequency may promote continued dominance by hardwoods and fire- and drought-resistant shrub communities, which is a regional forest management concern as wildfire size and severity continue to increase throughout the southwestern USA.

Conservation Priorities in Terrestrial Protected Areas for Latin America and the Caribbean Based on an Ecoregional Analysis of Woody Vegetation Change, 2001–2010

We determined protected area coverage and woody vegetation change in Latin America and the Caribbean at biome and ecoregion scales, for the years 2001 to 2010. For each ecoregion’s terrestrial protected area (TPA) and unprotected area, a linear regression of woody vegetation area against time (10 years) was used to estimate 2001 and 2010 woody vegetation, respectively. We calculated a conversion-to-protection index, termed the Woody Conservation Risk Index, and identified trends in relation to existing conservation priorities. As a whole, the region lost 2.2% of its woody cover. High woody cover loss was observed for the Moist Forests (3.4% decrease) and the Flooded Grasslands/Savannas (11.2% decrease) biomes, while Mediterranean Forests exhibited a 5.8% increase. The Dry Forest Biome, the most threatened biome worldwide, experienced a 2% regional gain, which was surprising as we expected the opposite given a net regional loss for all biomes. Woody cover was more stable in TPAs in comparison to areas with no protection. Deforestation inside and surrounding TPAs remains high in humid ecoregions. High overall ecoregion deforestation, with stable TPAs, characterized some Amazonian ecoregions, the Dry Chaco, and moist forests on the eastern Andean foothills of Ecuador and Peru. Woody regrowth inside and outside of TPAs was observed in the Sonoran-Sinaloan transition subtropical dry forests and the Sierra Madre Occidental pine-oak forests in Mexico.

Edible flowers commercialized in local markets of Pachuca de Soto, Hidalgo, Mexico

Background: Edible flowers are important food resources due to their high content of nutrients and bioactive compounds. In Mexico these resources have been part of the diet of indigenous and mestizo, and are also important sources of income for the families that cultivate, gather and sell them. Questions: What are the species of edible flower commercialized in local markets in Pachuca de Soto, Hidalgo, Mexico? How are they prepared? What are their nutritional contents and conservation risk categories according to literature? Studied species: Agave salmiana, A. mapisaga, Aloe vera, Arbutus xalapensis, Chenopodium berlandieri subsp.nuttalliae, Cucurbita pepo ssp. pepo, C. moschata, Dasylirion acrotrichum, Erythrina americana, Euphorbia radians, Myrtillocactus geometrizans, Phaseolus coccineus, Yucca filamentosa. Study site and dates: Local markets of Pachuca de Soto, Hidalgo, Mexico. January 2019 to March 2020. Methods: Interview-purchase with sellers and direct observations in markets. Bibliographic review of the nutritional contents of the recorded species and their conservation status. Results: We recorded 13 species of edible flowers and eight preparation methods. Five species are cultivated, five are gathered from the pine-oak forest or xerophilous scrub ecosystems and three are obtained from crops and natural ecosystems. The gualumbos (Agave salmiana and A. mapisaga) are the most commercialized flowers and had the most forms of preparation (six). Seven of the species traded are placed in a conservation risk category. Conclusions: The diversity of edible flowers used, and their preparation methods exemplify the traditional knowledge of the groups that handle them and their importance as food and economic sustenance.

The proposal of a new provisional border of range of the acidophilous oak forest Calamagrostio arundinaceae-Quercetum petraeae Hartm. 1934 Scam. et Pass. 1959 in central Poland

Abstract The range of acidophilous oak forest from Quercetea robori-petraeae Br-Bl. et Tx. ex Oberd. 1957 in Central Europe depends largely on the syntaxonomical concept used and is still provisional. The most continental association from this class occurring in Poland is Calamagrostio arundinaceae-Quercetum petraeae Hartm. 1934 Scam. et Pass. 1959. It is present in western and central Poland, but its eastern boundary is not well known. The aims of the study were to survey and document new patches of Calamagrostio-Quercetum in central Poland, to check the internal variation of the association and to summary the known distribution of it in lowlands of central-western and central Poland. 23 phytosociological relevés were made within new stands together with soil sampling. New relevé data was subjected to the numerical Wards classification together with acidophilous oak forests datasets from western Poland and oak-pine forests ones from eastern part of the Country. The new dataset was similar to Calamagrostio-Quercetum. Three subassociations were distinguished. Soil parameters and oak site index did not differ from acidophilous oak forest stands from other parts of Poland. The provisional range of Calamagrostio-Quercetum in central Poland was proposed to be moved by circa 60–90 km to the north-east (approximately as far as the Vistula river line) in order to include south-western part of Mazowsze.

Influence of Environmental Factors on Forest Understorey Species in Northern Mexico

Background: Understorey plants are key to maintaining forest structure and functioning. They protect the soil, improve its structure and fertility, reduce water run-off and sustain the below-ground biota, amongst other ecological services. However, little is known about the environmental conditions that regulate the occurrence of these plants. This study focuses on determining how canopy cover influences the occurrence of understorey species and identifying the most important soil properties that affect these species. The study area was a pine-oak forest in the Sierra Madre Occidental, an important source of ecological services for northwestern Mexico. Methods: To assess the conditions influencing the presence of herbaceous and shrub species, 25 soil variables were examined in relation to the species occurring in forest gaps and under the canopy. Sampling was conducted in five plots, each of 100 × 100 m. In each plot, 4 subplots, each of 20 × 20 m, were each subdivided in a grid of 2 × 2 m units, in which the presence-absence of herbaceous and shrub species was recorded (2000 units in total). Soil samples were extracted for analysis from the central point in each subplot. Data were analyzed using a Binomial Logistic Model (BLM) and Random Forest (RF) classification. Results: Understorey species were more strongly affected by soil variables than by their location in gaps or below canopy. The concentrations of Ca, P, K, Fe, Na, C, Zn, Mn, nitrates, organic matter, sand, silt, and percentage water saturation were statistically significantly associated with the presence of some plant species, whilst no significant differences were found in regard to preference for gaps or canopy, although several species were more frequent in open areas. Conclusions: Given the importance of the understorey cover in forest system functioning, we propose that understorey should be considered in integrated management and conservation practices for the temperate forests of northern Mexico.

Influence of avocado orchard landscapes on amphibians and reptiles in the trans‐Mexican volcanic belt

AbstractCommercial fruit orchards are embedded in a landscape of native forest and diverse kinds of agroecosystems. The landscape structure of these systems is a major driver of biodiversity response. Generally, it is assumed that high levels of biodiversity occur in perennial systems largely due to their high structural complexity. However, little is known about the influence of other landscape attributes on these levels of biodiversity. Avocado (Persea americana) constitutes about 25 percent of the global fresh fruit trade. In Mexico, avocado trees flourish about the same altitude as pine–oak forests (POFs). We studied the response of the local herpetofauna to conversion of POF to avocado orchards (AOs). We also explored the effects of forest cover on species that differ in their levels of habitat specialization. In the avocado belt in Michoacan, we sampled 12 sites representing a gradient of AO embedded in native POF to evaluate the variation in structure of local assemblages of amphibians and reptiles. Reduction of POF cover negatively affected specialist frog and snake species, but this relationship varied among buffers around sampling sites. Generalist species of amphibians and lizards showed increased abundances and richness in sites with low POF cover, whereas snake richness and abundance were higher in sites with high POF cover. Our study suggests that POF conversion to AO is a driver favoring the persistence and success of generalist but not specialist herpetofauna species. Therefore, to conserve the diversity of amphibians and reptiles in these agroecosystems, it is important to ensure high proportion of POF patches.Abstract in Spanish is available with online material.

Transition from Fire-Dependent Open Forests: Alternative Ecosystem States in the Southeastern United States

Land use and fire exclusion have influenced ecosystems worldwide, resulting in alternative ecosystem states. Here, I provide two examples from the southeastern United States of fire-dependent open pine and pine-oak forest loss and examine dynamics of the replacement forests, given continued long-term declines in foundation longleaf (Pinus palustris) and shortleaf (Pinus echinata) pines and recent increases in commercial loblolly (Pinus taeda) and slash (Pinus elliottii var. elliottii) pines. Shortleaf pine-oak forest historically may have been dominant on about 32 to 38 million ha, a provisional estimate based on historical composition of 75% of all trees, and has decreased to about 2.5 million ha currently; shortleaf pine now is 3% of all trees in the northern province. Longleaf pine forest decreased from about 30 million ha, totaling 75% of all trees, to 1.3 million ha and 3% of all trees in contemporary forests of the southern province. The initial transition from open pine ecosystems to closed forests, primarily comprised of broadleaf species, was countered by conversion to loblolly and slash pine plantations. Loblolly pine now accounts for 37% of all trees. Loss of fire-dependent ecosystems and their foundation tree species affect associated biodiversity, or the species that succeed under fire disturbance.

Consistently lower sap velocity and growth over nine years of rainfall exclusion in a Mediterranean mixed pine-oak forest

Mediterranean forests face an intensification of droughts caused by ongoing climate change. To improve our understanding of tree and forest responses to increasing drought, we explored over nine years, the effects of a 30% rainfall exclusion experiment on the water potential, sap velocity and primary and secondary growth of two co-occurring species (Quercus ilex and Pinus halepensis) in a French Mediterranean forest. In addition, native embolism was measured after six and nine years of exclusion onset. Water potentials decreased earlier during summer drought for both species in the rainfall exclusion plot, and to a higher extent during the drought peak for Q. ilex, involving earlier stomatal closure and reduced sap velocity. Sap velocity reduction persisted throughout the years in the exclusion plot. Outside summer the water potential difference between predawn and midday was similar between treatment which indicate that reduced water transport efficiency may be linked to decrease hydraulic conductance. Such differences were neither related to differences in xylem embolism, that remained similar between treatments, nor to change in secondary growth. In contrast primary growth measurements indicate that P. halepensis trees, and Q. ilex to a lesser extent, experienced reduction in total leaf areas in response to the rainfall exclusion. Globally, our results suggest that increase drought lead, for both species, to a decrease in sap velocity not mediated by increase embolism but rather by a reduction in primary growth. So far little conclusion can be drawn regarding the competitive advantage of one species over the other in the context of increasing drought related to climate change.

About naturalization of Berberis aquifolium in the territory of Nature Reserves of the Southern Coast of the Crimea

At the present stage of development of the economies of different states, the problem of biological invasions is considered one of the top-priorities. A special place among the different areas of research of biological invasions is occupied by the study of the most aggressive and dangerous alien plants in Protected Areas, as they pose a threat to the conservation of ecosystems and their biodiversity. The paper provides information on the phytocenotic diversity of communities with Berberis aquifolium Purch in native - in North America, as well as data on the distribution and degree of naturalization of the species in Eurasia, Australia, and New Zealand. It is established that Mahonia in many regions has the status of an invasive species, it is found both in anthropogenic disturbed and in natural communities, inhabiting a wide range of ecotopes (forest parks, meadows, forests, coastal dunes, etc.). On the Southern Coast of the Crimea, communities with Berberis aquifolium Purch were identified in forest park stands, as well as in coniferous and mixed forests, which belong to the classes Erico-Pinetea, Quercetea pubescentis according to the Braun-Blanquet classification. Preliminary data on the invasion of the species in the natural communities of two Protected Areas (PAs) - "Yalta Mountain Forest" and "Cape Martyan" are presented. The species is most widespread at altitudes from 200 to 400 m above sea level in pine, oak-hornbeam-pine and oak-pine forests belonging to the class Erico-Pinetea . In the lower forest belt at an altitude of up to 200 m above sea level, it is found in the pubescent oak-hornbeam and ash-oak-dogwood communities with Juniperus excelsa , J. deltoides , and Pinus pallasianae , which are part of the class Quercetea pubescentis .

Diversity, species richness distribution and centers of endemism of Lycianthes (Capsiceae, Solanaceae) in Mexico

Spatial patterns of plant diversity matter. Identifying areas of high species richness and endemism are crucial for understanding the evolution of plant diversity and community assemblages as well establishing sustainablility and conservation priorities. Lycianthes is the third most species-rich genus in the Solanaceae with 187 taxa (152 species, 10 subspecies and 25 varieties) native to the Americas and Asia-Pacific region. However, the distributions of the taxa are uneven and usually concentrated along mountain ranges in the Neotropic. In Mexico, the main mountain chains are known as the Mexican Transition Zone (MTZ), so we expected the highest species richness and endemism to be found there. Our aims were twofold; first, to determine the Lycianthes species richness in Mexico; and second, to analyze the spatial patterns. We used 2305 georeferenced records obtained from specimens examined in herbaria, electronic specimen databases and specimens cited in the literature. Then, we analyzed species richness and endemism using a grid-cell of 50 × 50 km, political divisions, biogeographic provinces, vegetation types, and elevation. In addition, endemism was quantified using weighted endemism (WE) and corrected weighted endemism (CWE). In Mexico, there were 48 taxa of Lycianthes, which included 44 species and four varieties. Of these, 20 species and two varieties were endemic. We found 14 cells of high species richness and eight centers of endemism, all located across the MTZ. The pine-oak forest resulted in the richest plant community followed by the cloud forest along an elevational gradient of 1000–2000 m. Likewise, endemism was found within the pine-oak forest of the MTZ, between 1000–2000 m of elevation. The geological history and climatic conditions of the MTZ could explain the diversity of Lycianthes there.

Legacy effects of seed dispersal mechanisms shape the spatial interaction network of plant species in Mediterranean forests

Abstract Seed dispersal by frugivores plays a key role in structuring and maintaining tree diversity in forests. However, little is known about how the spatial legacy of seed dispersal and early recruitment shapes spatial patterns and the spatial interaction network of plant species in mature forest communities. We analysed two fully mapped mixed Pine–Oak forest communities using spatial point pattern analysis to determine (a) the detailed structure of the intraspecific spatial patterns of saplings and adults, (b) the intra‐ and interspecific spatial interaction of saplings, adults and saplings relative to adults, (c) the spatial patterns of species richness at the community level and (d) whether seed dispersal mechanisms affect the plant–plant interaction networks and the ratio of adult to sapling neighbourhood densities used as surrogate for spatial self‐thinning. The intraspecific spatial patterns of saplings and adults showed in general complex nested cluster structures that were similar for sapling and adult stages, despite substantial self‐thinning in some dry‐fruited species. The spatial network of saplings was characterized by positive spatial interactions. Adults of several tree species facilitated saplings in their proximity; however, adults of dry‐fruited species, but not those of fleshy‐fruited ones, lost almost all positive interactions that occurred at the sapling stage. Besides, interaction strength between adults was positive and often significantly stronger if both species were fleshy‐fruited. At the community level, the forests were structured into multispecies clumps across all life stages. Synthesis. Our analyses highlight the importance of the spatial legacy of seed dispersal and early recruitment in the assembly of plant communities. Particularly, animal seed dispersal can lead to multispecies clusters and positive spatial associations across life stages in Mediterranean forests, with surprisingly little signatures of negative interactions. Our analysis suggests that changes of the spatial structure across plant life stages are driven by seed dispersal mechanisms and subsequent spatial self‐thinning, generating a spatial footprint at the sapling stage that conditions the long‐term interactions between adult plants. Combining spatial point pattern analysis with network analysis and species traits is a promising way to disentangle the processes underlying observed patterns of local diversity.

Features of coarse woody debris volume formation in fresh sudibrova conditions in Zmiini islands tract of Kaniv Nature Reserve

Dead wood (woody debris) is an important component of forest ecosystems. It performs a number of ecological and environmental functions. The article studies the peculiarities of the formation of coarse wood detritus volume and its qualitative structure in forests in the conditions of fresh sudibrova of the Zmiiini Islands tract of Kaniv Nature Reserve. The study of dead wood was carried out in 140-year-old pine-oak forests of natural origin on a permanent sample plot (0.24 ha) by identifying and measuring of standing and lying deadwood components. It was found that dead wood in the forest ecosystem was formed due to the dying of trees of five species: common oak (Quercus robur L.), Scots pine (Pinus sylvestris L.), Norway maple (Acer platanoides L.), small-leaved lime (Tilia cordata Mill.) and common hornbeam (Carpinus betulus L.), and has a volume 56.3 m3·ha–1. Dead wood volume is dominated by standing dead trees — 82.1%, and the share of lying dead wood, respectively, is 17.9%. The main part of dead wood volume is formed by two tree species — common oak and Scots pine, the share of which together is 94.3%. Common oak and Scots pine is characterized by a predominance of standing dead wood, while for other tree species — lying dead wood. In general, dead wood is formed by detritus of I–IV classes of destruction, at the same time detritus of class II decomposition has a significant advantage (70.5%), recently dead wood has a much smaller share (I class, 24.8%), and other classes of destruction have insignificant shares, which together do not exceed 5.0%. No woody detritus of the last (V) class of destruction was detected. Volume of standing dead wood is 46.2 m3·ha–1, and is formed by whole and broken dead trees. In terms of species composition, common oak has a significant advantage (74.5%), Scots pine has a much smaller share (25.1%), and the share of Norway maple is insignificant (0.4%). The total standing dead wood volume is dominated by wood of class II destruction (33.0 m3·ha–1, 71.4%) compared with class I (13.2 m3·ha–1, 28.6%). Lying dead wood is represented by four classes of destruction (I–IV), however, no woody debris was found at the late (last) stage of decomposition (class V). In terms of volume, the second class of destruction has an absolute advantage (6.7 m3·ha–1, 66.3%), much less class III detritus (2.3 m3·ha–1, 22.8%). Lying dead wood of common oak is represented by all four classes of destruction, among which III (40.5%) and I (33.3%) classes predominate. Lying dead wood of other tree species is characterized by the predominance of II or III classes of destruction. The main factors in the formation of woody detritus in the pine-oak forest in the Zmiiini Islands tract could be the impact of adverse climatic conditions (long periods without precipitation in summer), which led to the weakening of individual trees and their death, gusts of wind that broke individual tree trunks, low-intensity snow breaks, and the influence of biotic factors (insects, pathogens).

Hummingbird-plant interactions along an altitudinal gradient in northwestern Mexico

Comparing ecological networks along environmental gradients can enable a better understanding of the environmental filtering and coexistence mechanisms that determine community assembly. In the present study, we assessed hummingbird-plant network metrics at three sites along an altitudinal gradient in the Sierra Madre Occidental corresponding to tropical forest (148 and 289 m a.s.l.), ecotone (1131 and 1423 m a.s.l.) and pine-oak forest (1800 and 2218 m a.s.l.). We evaluated variation in the specialization (d’) of the hummingbird species and their visited plant species across altitude. We determined if hummingbird species inside the modules of the general network were separated by biogeographical origin, migratory behavior, or morphology. We assessed whether the role in the modular partition of hummingbird and plant species in the general network was related to traits of species. Finally, determined which traits were associated with the importance of different species within the network. We recorded 1050 interactions between 20 species of hummingbirds and 64 species of plants. We found that network metrics in the ecotone differed from other sites, reflecting the convergence between temperate and tropical forest flora and the midpoint in hummingbirds' altitudinal migration. As in previous studies, we found that hummingbird specialization was related to the bill length and found that the migratory status, particularly the altitudinal migratory species, was associated with the hummingbird specialization. The abundance of hummingbird species and flowers (ornithophilous and non-ornithophilous) along the gradient plays a central role in the importance within the network and in the formation of the modules.

Ecology typological assessment of forest vegetation of the North-Eastern Forest-Steppe of Ukraine

Recently, significantly increases the need for a detailed study of various aspects of the modern natural, spontaneous and artificially generated phytodiversity as the main element of the formation and regeneration of natural ecotypes structural elements for building national ecological network. It is necessary to examine various aspects of the natural and spontaneous vegetation formed. Based on the ecological specifics of the North-Eastern Forest-Steppe of Ukraine, a detailed analysis of natural and artificially formed forests on the floodplain, pine terrace and plateau of the rivers of the Dnieper and Seversky Donets basins, as well as in ravine-beam systems is required. Peculiarities of forest vegetation conditions, distribution of tree species and ecological conditions of their growth are given. According to forest management data, the area of the North-Eastern Forest-Steppe covered with forest vegetation is 336110.3 ha. The distribution of forest areas by edatopes is as follows: trophotopes — oak wood (220640.2 ha, 65.64%), sugruds (54739.2 ha, 16.29%), subors (52174.5 ha, 15.52%) and pine forests (8556.4 ha, 2.55%); hygrotopes — fresh conditions (282960.3 ha, 84.19%), dry (35576.7 ha, 10.59%), damp (12179.5 ha, 3.62%), moist (4634.3 ha, 1.38%), wet (749.0 ha, 0.22%) and very dry conditions (10.5 ha, 0.003%). There are 38 types of forests areas covered with forest vegetation, which are dominated by fresh maple-linden forest (183442.0 ha, 54.58%), a slightly smaller area occupied by fresh oak-pine forest (47040.9 ha, 14.00%) and linden-oak-pine sugrud (33999.3 ha, 10.12%), as well as dry maple-linden forest (28697.7 ha, 8.54%). The composition of forest-forming species is quite diverse and is represented by 60 species of woody and shrubby plants. The main forest-forming species is Quercus robur (190153.9 ha, 56.58%). Pinus sylvestris (86212.1 ha, 25.65%) and Fraxinus excelsior (20318.5 ha, 6.05%) have slightly smaller areas, all other species occupy small areas. Research a variety of forest habitats will provide an opportunity to plan the conservation, reproduction and protection of phytodiversity, including species of sozophytes from different conservation lists, as well as to balance the provision of ecosystem services by tree and shrub plantations of the North-Eastern Forest-Steppe of Ukraine.

Migratory Seasonality and Phenology by Birds in a Temperate Forest with Two Disturbance Conditions

Objective: The objective was to infer the effect of the variables phenology (migration-non-migration), seasonal (rainfall-dry season), sex and forest condition on the abundances of birds (resident-migratory) in a semi-preserved and disturbed oak pine forest.
 Design/methodology/approach: It was carried out in Monte Tlaloc, State of Mexico, under two conditions of apparent disturbance, semi-preserved oak pine forest and disturbed oak pine forest. Ten bird samplings were carried out with "count on point" with a fixed radius of 25 m, covering the 4 seasons of the year and migratory periods. With the previous data, the Relative Abundance Index (RAI) was estimated. To infer the effect of the variables phenology, seasonality, sex and forest condition on the abundances of birds, generalized linear models were elaborated.
 Results: The IAR of the birds registered in the semi-considered pine forest indicates that the species with the lowest presence was Aphelocoma ultramarina (0.002) and with the highest frequency Empidonax sp. (0.13), unlike to that found in the disturbed pine forest where the lowest IAR corresponded to Colaptes auratus (0.003) and with the highest appearance was Ptiliogonys cinereus (0.23). The Generalized Linear Model suggested that forest condition and phenology are significantly related to the frequency of species.
 Limitations on study/implications: In this study it was found that the abundance of birds was affected by the condition of the forest and that the phenology (migration-non-migration), seasonal (rain-dry season), sex and condition of the forest were related to the abundance of birds. Four species classified as under Special Protection and two Threatened according to NOM-059 were registered as well as the presence of four endemic species which highlights the importance of conserving these ecosystems.
 Findings/conclusions: The fauna communities present in Monte Tláloc highlight the importance of conserving the pine-oak forests since this site is part of the Eje Neovolcanico Transversal.

Wild turkey (Meleagris gallopavo mexicana) monitoring: Innovation in sampling and estimator of population density

Objective: To estimate the population of wild turkey (Meleagris gallopavo, mexicana) and its density in ecosystems of its distribution.Design / methodology / approach: A method based on random sampling with a population density estimator was designed. The design was based on the observation of wild turkeys that go to attraction sites (feedlots) of 2,500 m 2 (50 X 50 m) counted in 12 h a day, three consecutive days. For the total of random sites, the criterion of one site for every 300 ha of surface under study was used. The study was carried out on March 1, 2 and 3, 2019 in 3,000 ha of pine-oak forest, in Monte Escobedo, Zacatecas, Mexico. Observations were made from a fixed point 25 m from each site, from 6:00 a.m. to 6:00 p.m. The attraction sites were located at a random distance within 10 systematically fixed transects in the study area.Results: The results showed a population of 66 turkeys in 3,000 ha, with a density of 0.022 turkeys ha -1 . Limitations / implications: The application of the method was useful for the monitoring of wild turkey in the pine-oak forest, showing that it is a method that does not affect the population, which does not require long sampling times, is reliable, low-cost, and easy to carry out. The method is not reliable in ecosystemsthat do not allow the location of high visibility sites.Findings / conclusions: Considering the distribution of wild turkey in Mexico, the method is a new alternative applicable to population studies of wild turkey.

Investigating linkages between the size-growth relationship and drought, nitrogen deposition, and structural complexity in western U.S. Forests

Understanding how stand structure responds to stresses such as drought and pollution could aid forest managers in evaluating silvicultural treatment success, predicting treatment durability, and designing adaptive management approaches. The size-growth relationship (SGR), a measure of growth partitioning among different size trees in a stand, may provide a means of linking stresses impacting individual trees to forest stand development and growth. No study to date has tested SGR’s response to drought and pollution, specifically N deposition, across landscapes. We combined Forest Inventory and Analysis (FIA) stand development and plot-level lichen bioindicator data on N deposition with climate data denoting moisture availability. Using linear regression, we examined SGR, stand structural complexity, individual tree growth and mortality in largely multi-aged, mixed species stands in California, Oregon, and Washington, USA, coniferous and pine-oak forests. Our goals were to determine a) the influence of moisture availability and/or N deposition on SGR, b) whether SGR translates to differences in stand structural complexity over time, and c) the extent to which SGR mediates the impacts of abiotic stress on tree growth and mortality. Consistent with previous research, our results indicated that SGR increased with stand density, indicative of larger trees possessing a disproportionate advantage in aboveground competition for light. SGR declined linearly with stand age, trending over time towards disproportionately slow large-tree growth. SGR strongly increased with low-moderate bioindicated N deposition, which is consistent with past findings that SGR increases with site quality and suggests that N deposition disproportionately increases growth in larger trees. We did not find evidence that drought stress (as indicated by the Palmer Drought Severity Index) influenced SGR. Stands that were already more structurally complex showed further gains in complexity under high SGR (disproportionately rapid large-tree growth), whereas stands that were initially structurally simpler increased in complexity under low SGR (disproportionately slow large tree growth). As such, individual-tree growth and mortality may drive changes in complexity. Our results support the utility of SGR as a predictor of how stress impacts stand structure, but only when accounting for initial structural complexity. Our findings also have implications for the design and durability of silvicultural treatments, given that silvicultural prescriptions often involve the manipulation of tree size distributions. Moreover, these findings underscore the importance of accounting for the historical influence of N deposition on stand development during treatment planning, as well as the likelihood of socioeconomic changes altering N deposition in the future.