Large Pine Research Articles

Biogenic secondary organic aerosol participates in plant interactions and herbivory defense.

Biogenic secondary organic aerosols (SOAs) can be formed from the oxidation of plant volatiles in the atmosphere. Herbivore-induced plant volatiles (HIPVs) can elicit plant defenses, but whether such ecological functions persist after they form SOAs was previously unknown. Here we show that Scots pine seedlings damaged by large pine weevils feeding on their roots release HIPVs that trigger defenses in neighboring conspecific plants. The biological activity persisted after HIPVs had been oxidized to form SOAs, which was indicated by receivers displaying enhanced photosynthesis, primed volatile defenses, and reduced weevil damage. The elemental composition and quantity of SOAs likely determines their biological functions. This work demonstrates that plant-derived SOAs can mediate interactions between plants, highlighting their ecological significance in ecosystems.

Stand diversity increases pine resistance and resilience to compound disturbance

BackgroundDrought, fire, and insects are increasing mortality of pine species throughout the northern temperate zone as climate change progresses. Tree survival may be enhanced by forest diversity, with growth rates often higher in mixed stands, but whether tree defenses are likewise aided remains in question. We tested how forest diversity-productivity patterns relate to growth and defense over three centuries of climate change, competition, wildfire, and bark beetle attack. We used detailed census data from a fully mapped 25.6-ha forest dynamics plot in California, USA to conduct a spatially explicit, dendroecological assessment of large-diameter Pinus lambertiana survival following fire reintroduction. Our structural equation models investigated direct and indirect pathways by which growth, defense, and forest composition together mediated pine resistance and resilience.ResultsIn the historical era of frequent, mixed-severity fire (pre-1900), trees that were ultimately resistant or susceptible to the post-fire bark beetle epidemic all showed similar growth and defenses, as measured by axial resin duct traits. During the era of fire exclusion (1901–2012), however, susceptible trees had slower growth. Following fire re-entry in 2013, both growth and defense declined precipitously for susceptible trees, resulting in fatal bark beetle attack. Spatial analysis showed that monodominant crowding by shade-tolerant competitors contributed to the long-term stress that prevented susceptible trees from recuperating defenses quickly following fire re-entry. For beetle-resistant trees, however, we found positive feedbacks between diversity, growth, and survival: trees in species-rich communities had higher growth rates pre-fire, which promoted a rapid recuperation of defenses following fire that helped trees resist bark beetle attack. Overall, this associational resistance outweighed associational susceptibility (+8.6% vs. −6.4% change in individual tree survival odds), suggesting a relaxation effect that ultimately allowed 58% of large pines to survive.ConclusionsThough climate change threatens forest biodiversity, biodiversity is key to forest climate adaptation in return. Our findings demonstrate centennial-scale feedbacks by which forest diversity increases pine resistance and resilience to climate-amplified disturbances. The spatially explicit, dendroecological framework provides new insights into diversity-productivity theory, while also informing climate-adaptive forest management by identifying thresholds of tree density and richness that maximize large pine survival.

Study on the Detection Technology of Injection Residue in the Trunk of Large (Ancient) Pine

Study on the Detection Technology of Injection Residue in the Trunk of Large (Ancient) Pine

Can Moisture-Indicating Understory Plants Be Used to Predict Survivorship of Large Lodgepole Pine Trees During Severe Outbreaks of Mountain Pine Beetle?

Abstract Why do some mature lodgepole pines survive mountain pine beetle outbreaks while most are killed? Here we test the hypothesis that mature trees growing in sites with vascular plant indicators of high relative soil moisture are more likely to survive mountain pine beetle outbreaks than mature trees associated with indicators of lower relative soil moisture. Working in the Clearwater Valley of south central British Columbia, we inventoried understory plants growing near large-diameter and small-diameter survivors and nonsurvivors of a mountain pine beetle outbreak in the mid-2000s. When key understory species were ranked according to their accepted soil moisture indicator value, a significant positive correlation was found between survivorship in large-diameter pine and inferred relative high soil moisture status—a finding consistent with the well-documented importance of soil moisture in the mobilization of defense compounds in lodgepole pine. We suggest that indicators of soil moisture may be useful in predicting the survival of large pine trees in future pine beetle outbreaks. Study Implications: A recent outbreak of the mountain pine beetle resulted in unprecedented levels of lodgepole pine mortality across southern inland British Columbia. Here, we use moisture-dependent understory plants to show that large lodgepole pine trees growing in sites with high relative moisture are more likely than similar trees in drier sites to survive severe outbreaks of mountain pine beetle—a finding that may be related to a superior ability to mobilize chemical defense compounds compared with drought-stressed trees.

Methyl jasmonate, salicylic acid, and oxalic acid affects growth, inducible defenses, and pine weevil resistance in Norway spruce.

The large pine weevil (Hylobius abietis) is a major regeneration pest in commercial forestry. Pesticide application has historically been the preferred control method, but pesticides are now being phased out in several countries for environmental reasons. There is, thus, a need for alternative plant protection strategies. We applied methyl jasmonate (MeJA), salicylic acid (SA) or oxalic acid (OxA) on the stem of 2-year-old Norway spruce (Picea abies) plants to determine effects on inducible defenses and plant growth. Anatomical examination of stem cross-sections 9 weeks after application of 100 mM MeJA revealed massive formation of traumatic resin ducts and greatly reduced sapwood growth. Application of high concentrations of SA or OxA (500 and 200 mM, respectively) induced much weaker physiological responses than 100 mM MeJA. All three treatments reduced plant height growth significantly, but the reduction was larger for MeJA (~55%) than for SA and OxA (34-35%). Lower MeJA concentrations (5-50 mM) induced comparable traumatic resin duct formation as the high MeJA concentration but caused moderate (and non-significant) reductions in plant growth. Two-year-old spruce plants treated with 100 mM MeJA showed reduced mortality after exposure to pine weevils in the field, and this enhanced resistance-effect was statistically significant for three years after treatment.

Response of stream macroinvertebrate communities to forest harvesting in the Piedmont region of North Carolina

Forest disturbances have significant effects on water quality and quantity, river geomorphology, and the ecology of receiving waterbodies. Riparian forests provide numerous functions for aquatic communities including retaining fine sediments and nutrients, controlling water temperature, and providing food sources and habitat for aquatic organisms. Forestry Best Management Practices (BMPs) use riparian forests as buffers to mitigate potential sources of disturbance to aquatic ecosystems from forest management. The objective of this study was to quantify the impacts of timber harvest on stream macroinvertebrates in the Piedmont region. We assessed the changes in macroinvertebrate communities and identified their relationships with specific hydrologic and water quality parameters. We used a paired watershed approach to quantify the response of watershed hydrology and water quality to clearcut forest harvesting with the use of BMPs in the Hill Demonstration Forest and Umstead Research Farm in central North Carolina. We sampled macroinvertebrates and monitored water quality in the first-order streams, and surveyed vegetation within riparian zones one year preharvest (2010) and four years postharvest (2011–2014). We found more sensitive species (indicated by biotic index classifications), scrapers, and Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa from the harvested watershed than in the reference watershed at the Umstead Research Farm site. No differences were detected between the reference and treatment watersheds at the Hill Demonstration Forest site. More sensitive species were present in watersheds with the highest pine basal area and in-stream total organic carbon (TOC) loads. More scrapers were present in watersheds with low hardwood basal area, high stream flow, and more vines. EPT abundance was higher in watersheds with high stream flow, large pine trees, and thick leaf litter layer. EPT abundance was lower in watersheds with large hardwood trees and high TOC loads. Overall, sensitive species, scrapers, and EPT abundance were lower in the Umstead Research Farm reference watershed than in any other watershed. We conclude that, in contrast to similar studies in the region, clearcut harvesting with the use of BMPs did not cause detectable negative effects on macroinvertebrate communities. Moreover, water quality as determined by macroinvertebrates may even be improved in some cases following clearcutting. This study provides a better understanding of how macroinvertebrate communities in Piedmont streams change after harvesting and what watershed characteristics may be driving these changes. This information is useful in characterizing macroinvertebrates in headwaters in the Piedmont, and helps land managers protect aquatic resources across the region.

Adsorptive Removal of Dye (Methylene Blue) Organic Pollutant from Water by Pine Tree Leaf Biomass Adsorbent

In this laboratory batch adsorption study, the raw pine tree leaf biomass solid waste adsorbent material was used for the removal of methylene blue (MB) dye from water at different physicochemical process conditions. The characteristics of adsorbents were determined for particle size, surface area, the existence of functional group identification, and the morphology of the adsorbent surface. The adsorption was performed at different process conditions, which include solution pH, dye concentrations, adsorbent doses, and temperature, respectively. In this study, it was found that MB dye adsorption increased with increases in solution pH and adsorbate MB dye concentration but decreased with adsorbent doses and temperature at fixed process conditions. The Langmuir isotherm model was best fitted with the experimental equilibrium data, with a higher linear regression coefficient (R2) value of 99.9% among the two widely used Langmuir and Freundlich adsorption isotherm model equations. The maximum Langmuir monolayer adsorption capacity of raw pine leaf was found to be 36.88 mg/g, which was comparable with other reported adsorbent capacities towards methylene blue (MB) dye adsorption. The value of the separation factor, RL, from the Langmuir isotherm model equation gives an indication of favorable adsorption. Thermodynamic parameters such as standard Gibbs free energy change (ΔG0), standard enthalpy change (ΔH0), and standard entropy change (ΔS0) indicated that the methylene blue (MB) dye adsorption by pine tree leaf biomass was spontaneous and exothermic in nature and that the mechanism of adsorption was mainly physical adsorption. Finally, limitations and future studies are also discussed here. The outcome of this batch adsorption study may result in the valorization of locally available large pine tree leaf residue waste, which could be used in water purification.

Ordinal Date and Tree Diameter Influence Swallow-Tailed Kite (Elanoides forficatus) Nest Survival

ABSTRACT Swallow-tailed Kites (Elanoides forficatus) continue to rebound from population declines during the late 19th and early 20th centuries, and they are considered a species of concern in several southeastern states in the United States. During 2018–2019, we located and monitored 132 active Swallow-tailed Kite nests in and around the Corkscrew Regional Ecosystem Watershed Wildlife and Environmental Area in southwest Florida, USA, to determine how nest site characteristics affect nest survival. Including both years, the earliest active nest (with eggs or young) was discovered on 12 March and the latest nest fledged young on 23 July. Modeled survival of nests from the onset of incubation to fledging was 57.7% (95% CI: 44.5–68.9) and apparent nest survival was 48.7%. Daily survival rate was negatively correlated with ordinal date. Consequently, nests initiated early in the nesting season (mid-March) were more than three times as likely to fledge young as nests initiated late in the season (mid-May). Daily nest survival was positively correlated with nest tree diameter at breast height, indicating that Swallow-tailed Kites had greater nest survival when using larger, more mature trees. We found 99.0% (n = 102) of Swallow-tailed Kite nests in south Florida slash pine (Pinus elliottii var. densa) trees and one nest in bald cypress (Taxodium distichum). Trees used for nesting in our study area were among the largest nest trees reported for the species. Our results suggest that the large pine trees and large cypress trees formerly available in old growth bottomland hardwoods and lowland pine forests of the United States may have provided superior nesting opportunities for Swallow-tailed Kites.

Red-cockaded woodpecker habitat characteristics associated with partial brood loss in the Upper East Gulf Coastal Plain, USA

Some red-cockaded woodpecker (RCW) Dryobates borealis populations remain understudied. This is notable because management that incorporates population demographics and site characteristics may benefit RCW recovery. The Oakmulgee Ranger District of the Talladega National Forest (Alabama, USA) has no wiregrass Aristida stricta, small forest stand sizes, rolling topography, and contains an understudied RCW population. Our goal in the Oakmulgee was to characterize RCW habitat, possibly identify ways in which habitat differed from other regions, and estimate associations between habitat and reproductive output. We found that 70.2 and 92.5% of sampled stands met recovery standard thresholds for small and large pine basal area (BA) as defined in the United States Fish and Wildlife Service (USFWS) RCW Recovery Plan. While 74.6% of longleaf pine Pinus palustris-dominated stands met the threshold for overstory hardwood canopy composition, 60.0% of loblolly pine P. taeda-dominated stands did not. Few stands met the recommended percentage of herbaceous understory (19.8%) or recommended absence of hardwood midstory. A lower rate of partial brood loss was associated with a greater area of large pines (≥25.4 cm diameter at breast height; DBH), a smaller area of small pines (≥10 and <25.4 cm DBH), a larger area burned in the dormant season, and higher RCW density. In our models, hardwood overstory and midstory did not influence egg or hatchling production. Hardwoods in the Oakmulgee could contribute to unfavorable habitat, as indicated in the USFWS RCW Recovery Plan, as well as relate to variation in habitat across the RCW’s range. Regions of the RCW’s range are understudied, and limited staffing and funding impede advances in understanding and conservation.

Spatial determinants of tree recruitment in mixed stands in southeastern Poland- silver fir's interaction with lowland tree species

Silver fir (Abies alba Mill.) is a typical mountain tree species, but it can also grow in lowlands below 300 m a.s.l., where it must coexist with a variety of competitors. Much less were studied in the northeastern part of its natural range, where annual precipitation varies between 500 and 600 mm, distinctly less than in the mountains. The general objective of this study was to investigate the regeneration process of silver fir in mixed lowland forests in regions with water shortage. The evaluation of spatial relationships between old, dominant and newly established trees was used to clarify the mechanisms of tree species coexistence. The study was conducted in managed and protected stands in Janów Forests in the southeastern part of Poland. We selected mature forest stands (oldest trees older than 100 years) representing three types of mixed stands in nature reserves, as well as in comparable managed forests. Data was collected on 500 m2 sample plots established randomly in each stand category (20 sample plots × 6 stands). Silver fir as the target tree showed statistically significant segregation from other species in 15 cases. Small silver fir trees were associated with large pines in two forest types and segregated form large firs in one. The spatial relationships between fir and black alder were negative. Black alder was the second species with the most statistically significant spatial relationships with other tree species (11 cases). Alders separated from large pines and large firs and from medium and small silver firs. Strong segregation of medium-sized hornbeam from the small class of silver fir was observed. Our study showed that silver fir natural regeneration and colonization of new areas at the northeastern limit of its range are limited by low seed rain density, interactions with other competing species, and local site conditions. Areas with moderately high water table are potentially suitable for fir regeneration, but black alder has a competitive advantage in wetter parts of forest stand. The major advantage of such sites is the absence of beech populations, which are an important competitor to fir in the central European mountains, but a likely equally important limitation would be the presence of hornbeam populations. Our results suggest that less intensive cuttings at carefully selected places are more conducive to fir regeneration than more intensive salvage cuttings.

Анализ фаунистического сходства сообществ пернатых хищников некоторых местообитаний Алтайского края и республики Алтай

Birds of the orders Falconiformes, Accipitriformes, and Strigiformes are at the top of the food chain, and therefore, they are the most vulnerable to changes in the natural environment caused by human activities. The condition of populations of birds of prey can serve as a criterion for the well-being of a biotope. The current state of nesting groups of many species of birds of prey in Altai Krai is of great concern. The survival of many of them is now in question, as numerous threats are generated by lumbering, mining, farming, poaching, growing energy infrastructure, and other human activities. In this regard, there is an urgent need for a detailed study of the species composition and population numbers of birds of prey and owls in the Altai region, as well as regular monitoring of populations that still exist. In this paper, we made a comparative analysis of breeding groups of raptors of different habitats of the Russian part of the Altai region: the Ukok plateau, the Ulandryk River gorge, the Anui River valley and the Kasmalinsky pine forest. Data on the species composition are taken from both our works and literature. We carried out a comparative analysis of breeding groups of birds using the coefficients of faunistic similarity of Jaccard and Sörensen. Since we had to compare more than two breeding groups, we used Mountford cluster analysis to order the similarity coefficients, which consists in sequentially combining the most similar groups. The results of the analysis of the Jaccard and Sörensen coefficients turned out to be very similar. The greatest similarity of the nesting species composition was found between the Anui River valley and Kasmalinsky pine forest (Кj=0.63; Кs=0.77). More significant differences were found between the Ukok plateau and the Ulandryk River gorge (Кj=0.44; Кs=0.60). And the maximum differences were found between the Kasmalinsky pine forest and the Ulandryk gorge (Кj=0.17; Кs=0.29). These differences can be explained by the specifics of the physical and geographical conditions and vegetation cover of different habitats of the Altai region. The poor species composition of raptors in the Ulandryk Gorge (7 species of birds of prey and 1 species of owls) is due to the complete absence of woods in this habitat. Therefore, there are no tree-nesting species here. The gorge is inhabited only by those species of raptors that can build their nests on the rocks. There are also no species here that require special types of prey, which are not sufficient in this biotope. The richness of the species composition of raptors (18 species of birds of prey and 8 species of owls) in the Kasmalinsky pine forest is because most species are dendrophiles and find here the optimal substrate for nests – large pines. The forage base here is also optimal for most species of raptors. Only specific mountain-steppe and high-mountain species do not nest in the pine forest. According to the species composition of raptors, habitats such as the Ukok plateau and the Anui river valley are in an intermediate position between the Ulandryk gorge and the Kasmalinsky pine forest. Both have rocky outcrops suitable for nesting and trees. Therefore, in these biotopes birds that prefer nesting both on rocks and in trees can be found.

Крупные хищные птицы в заповеднике «Нургуш», Кировская область, Россия

Крупные хищные птицы в заповеднике «Нургуш», Кировская область, Россия

Acetamiprid used to preventHylobius abietisdamaging young trees poses a very low risk of causing water contamination provided good forestry practices are followed

AbstractA study of chemical runoff following the use of acetamiprid as a pre-treatment and top-up spray to prevent damage from the large pine weevil (Hylobius abietis L.) to young trees was undertaken at a restock site in mid-Wales. The site was specifically selected to pose a high risk of chemical runoff, being a high elevation, headwater catchment with stagnopodzol soils, subject to high rainfall. Water samples were collected before, during and after each treatment from six points around the site, as well as from a nearby stream that acted as a control. Only 1 of the 90 water samples collected detected acetamiprid at levels above the limit of quantification of 0.005 μg l−1 (i.e. 0.000000005 g in 1 l of water) and this appeared to be due to wash-off of residues from the plastic bags the trees had been delivered to the site in, which had been temporarily placed within a dry road drain. The recorded concentration of 0.1022 μg l−1 of acetamiprid was low, being only 20 per cent of the Predicted No Effect Concentration (PNEC) of 0.5 μg l−1. Neither of the top-up spray applications resulted in water contamination at any of the sampling points. The results show that the good forestry practice measures employed were effective in preventing contamination of stream waters by acetamiprid. The use of 10-m buffers between forest drains and receiving streams, as per standard good forestry practice in the UK, should be more than adequate to prevent any chemical runoff contaminating watercourses. However, it is recommended that forest practice is further tightened in relation to the placement and handling of planting bags on site. Bags should not be placed within or near road or forest drains, and they should be removed from the site at the end of each day.

IDENTIFIKASI KOMPONEN UTAMA MINYAK ATSIRI DAUN UJUNG ATAP (Baeckea frutescens L.) DAN UJI AKTIVITAS ANTIBAKTERI TERHADAP BAKTERI Escherichia coli IDENTIFICATION OF MAIN COMPONENTS OF LEAF TIP ESSENTIAL OIL (Baeckea frutescens L.) AND ANTIBACTERIAL ACTIVITY TEST AGAINST Escherichia coli BACTERIA

Baeckea frutescens L is a tropical plant that usually grows in coastal areas. Its leaves resemble needles with trees that resemble large pines. Baeckea frutescens L can be found in various regions in Indonesia, one of which is in Nanjung Village, Ketapang Regency, and West Kalimantan. Baeckea frutescens L essential oil was obtained by isolation using steam distillation. The results obtained from the isolation of the essential oil of Baeckea frutescens L was a yield of 0.0037% (v/v) and a density of 0.874 g/mL. Baeckea frutescens L essential oil was then analyzed using GC-MS. The results of the analysis showed that there were 32 compounds, with the main compounds being -ocimene, eucalyptol, -myrcene, -humulene, -terpineol. The results of the antibacterial activity test against Escherichia coli bacteria, concentrations of 5% (15.9 mm), 2.5% (15.6 mm), 1.25% (12.9 mm) and 0.625% (11.8 mm).

Southern Pine Beetle Dendroctonus frontalis (Coleoptera: Curculionidae: Scolytinae)

The southern pine beetle (SPB), Dendroctonus frontalis Zimmermann, has been the most economically important forest insect in the pine timber industry in the southern United States. From 1960 through 1990, the bark beetle caused economic losses estimated at $900 million (Price et al. 1992). From 1998 to 2002, a four-year outbreak in the southern Appalachian Mountains affected more than 1 million acres with an economic loss of more than $1 billion (Clarke and Nowak 2009). In 2001,17,599 acres of pine forest were damaged by SPB in Florida alone, causing an estimated $38 million in damages.
 While the spectacular outbreaks have captured attention, equally interesting are the long periods of the beetle absence between outbreaks, and the factors that maintain its low populations. Recent observations suggest that in natural conditions the beetle is a rare insect, and rarely responds with an outbreak unless silvicultural practices create a suitable environment: overstocked, even-aged, large pine stands. Despite many decades of research on the beetle ecology, we lack a complete understanding of its population dynamics, and its original (preindustrial) ecology remains elusive (Asaro et al. 2017). Fortunately, silvicultural practices leading to resistant stands are now commonplace, and principally include thinning (either mechanical or by fire) and rapid detection and removal of infestations (Nowak et al. 2015).

Comprehensive comparison of treatments for controlling the large pine weevil (Hylobius abietis) in Central Europe

Adults of the large pine weevil (Hylobius abietis) cause serious damage to coniferous seedlings and are among the most important forest pests in Europe. Seedling protection by chemicals is gradually being restricted or banned for environmental reasons, and non-chemical alternatives are therefore needed. In this 3-year study, we compared the following five treatments for protecting Norway spruce seedlings against H. abietis in the Central European mountains where the weevil is especially abundant: alpha-cypermethrin sprays (the only chemical treatment); coating with sprayed glue (Vermifix); wax coating with C and F types (Norsk Wax); and physical protection with collars. The same block design was set up at a clear-cut site and at a nursery site to compare seedling mortality and wax quality under “wild conditions” with pests and under “ideal conditions” without pests. Repeated application of alpha-cypermethrin was the most effective and least expensive method to protect seedlings against H. abietis. Among the four non-chemical methods, repeated application of glue was the most effective. Because collars were moderately effective but not cost-effective, we do not recommend the use of collars. Wax was inexpensive and environmentally safe but protected seedlings for only 1 year; the newer F type of wax performed better than the C type of wax, and perhaps the F type can be improved. In general we found that seedlings at sites with high numbers of H. abietis require protection for at least 3 years. We conclude by providing an overview of all methods currently available for managing H. abietis in forests.

조경수의 생산 관리를 위한 식재 수종 및 규모의 시계열 분석 - 수도권 민간건설 아파트 단지를 중심으로 -

This study was conducted to understand the change time-series of landscape trees planted in apartment complexes and to predict the demand for pine trees among landscape trees. From 2003 to 2020, the average number of trees used in apartment complexes in the Seoul metropolitan area were 51, and various types of trees were used in the late 2010s compared to the mid-to-late 2000s. The average planting quantity was 149,567trees/1 complex, and the time series change was not noticeable. Comparing evergreen trees and deciduous trees, there was a difference between the planted species and the planted quantity. Compared to evergreen trees, deciduous trees were planted with relatively diverse species. Evergreen trees were planted in large quantities, with fewer varieties than deciduous trees. The types of trees and shrubs consist of a ratio of 6:4, and shrubs accounted for 97.6% of the total planting volume. Compared to the amount of planting, the varieties of trees planted are not diverse. When analyzing the planting status of pine trees with high preference and use value of landscaping trees, the planting volume tends to increase, and in particular, the planting ratio of large pine trees is increasing. Predicting the demand for pine tree planting in apartment complexes will continue to increase the amount of planting, especially with special trees with a root diameter of 40 cm or more. In response to these changes in demand for landscaping trees, a strategy is required to discover and produce various plant materials. In particular, since the demand for large pine trees is continuously expected to increase, production management should be carried out so that pine trees with the shape and specifications required by the market can be supplied.

PINUS SYLVESTRIS L. REGENERATION FROM SEED TREES IN VACCINIOSA AND MYRTILLOSA

Scots pine (Pinus sylvestris L.) is an economically important tree species in temperate forests, including Latvia. Purposeful selection work has resulted in the provision of faster-growing planting material for forest planting. Natural restoration initially requires less investment, it has several disadvantages. When using this method, it must be considered that the forest stands will have an uneven species composition, the age and height of the trees will differ. The study was carried out in young naturally regenerated stands in Vacciniosa and Myrtillosa forest site type and compared with planted stands The aim of the study was to evaluate the natural regeneration and last 5 year tree height increment of Scots pine regenerated from the seed trees in the Vacciniosa and Myrtillosa, compared to planted stands, as well as to assess the impact of tree health on pine height increment. In total 10 young stands were surveyed, 66 sample plots were established and 704 trees were measured. The area of the temporary sample plot was 25 m2 with a radius of 2.82 m. Comparing the annual height increases of Scots pine, both in naturally regenerated and planted young stands in Vacciniosa and Myrtillosa, it was found that there are statistically significant differences between forest types, stand origin type, as well as in existing stands in the last 5 years by years (p <0.05). The most significant damage to young pine stands is caused by needle cast, ungulates, and large pine weevil.

Canopies, the Final Frog-tier: exploring responses of a specialist treefrog to prescribed fire in a pyrogenic ecosystem

BackgroundPine flatwoods of the southeastern United States were shaped by frequent fires. Land managers use prescribed fires to control fuels but also to restore historical fire dynamics. Broad outcomes of this practice are well-understood, but impacts on many organisms are still being explored. Frogs, for example, have upland and wetland requirements, limited mobility, and skin susceptible to desiccation. Treefrogs spend most of their lives in uplands away from water. When fire approaches, animals may escape to an unburned area, shelter in place, or be killed by the fire. We examined which of these mechanisms is the prevailing short-term response for a specialist treefrog in a pyrogenic flatwood system.ResultsWe assessed the short-term impacts of prescribed fire on the dynamics of an upland flatwood specialist, the pinewoods treefrog Dryophytes femoralis, using a replicated before-after-control-impact field experiment. We set pipes as treefrog refugia at 3 m, 6 m, 9 m, and 9+ m in 12 pine trees spread evenly across two treatments: reference trees in units burned in 2020 and trees in units with 2021 prescribed fire. Prescribed fires occurred on 16 April and 21 July 2021. Every 2 weeks between 5 March and 5 September, we checked pipes for frogs and assigned them unique color marks. We observed 78 individuals with 199 additional recaptures. We modeled abundance (as raw counts), survival, and vertical movement using mark-recapture methods, multi-state, and mixed linear models with a Bayesian framework. Survival and recapture were comparable among prescribed fire treatments, but abundances and movement probability varied. Frogs in trees in areas burned during the study were more likely to stay in place and less likely to descend to lower heights. We observed more frogs in trees after a 2021 fire compared to reference trees.ConclusionsThe prevailing mechanism for resiliency to fire for pinewoods treefrogs was migration up large pines, then likely recolonization to lower vegetation layers when plants regreen post-fire. This substantiates conclusions from other works that the integrity of mature pines is key to sustaining native biodiversity. Future work and management should consider the three-dimensional structure of habitat when developing burn prescriptions and study designs.

Comparison of foraging tool use in two species of myrmicine ants (Hymenoptera: Formicidae)

Many ant species are known to exhibit foraging tool use, during which ants place various debris items (e.g., pieces of soil, leaves, pine needles, etc.) into liquid food, and then they carry the food-soaked tools back to the nest. In the present study, we compared the tool-using behavior in captive colonies of two closely related myrmicine ants with different feeding preferences: Aphaenogaster subterranea, an omnivorous species, and Messor structor, a mainly granivorous seed-harvester species. We supplied foraging ants with honey-water baits and six types of objects they could use as tools: sand grains, small soil grains, large soil grains, pine needles, leaves, and sponges. We found that the workers of A. subterranea both dropped more tools into honey-water baits and retrieved more of these tools than the workers of M. structor. While A. subterranea preferred smaller tools over larger ones, tool preferences for M. structor did not differ significantly from random. In addition, tool dropping was significantly faster in A. subterranea, and both the dropping and retrieving of tools began significantly earlier than in M. structor. For Aphaenogaster species that regularly utilize and compete for liquid food sources, the ability to efficiently transport liquid food via tools may be more important than it is for seed-harvester ants. Dropping tools into liquids, however, may still be useful for seed-harvester species as a means to supplement diet with liquid food during periods of seed shortage and also to serve as a means of getting rid of unwanted liquids close to the nest.