Red Maple Acer Rubrum Research Articles

Effect of Herbivory on the Nutritional Value of Six Hardwood Species for White-Tailed Deer in the Allegheny Forest

Abstract Herbivores alter plant quantity and quality through direct tissue consumption and indirectly via the structural and chemical allocational strategies plants deploy in response to herbivory. Herein, we examine how browsing by white-tailed deer Odocoileus virginianus alters nutritional quality of six regenerating hardwood species: red maple Acer rubrum, black cherry Prunus serotina, birch Betula spp., pin cherry Prunus pennsylvanica, white ash Fraxinus americana, and American beech Fagus grandifolia. Using an established, large-scale experiment that manipulated deer access to fenced plots, we tested whether browsing altered the nutritional quality and biomass as well as nutritional capacity to support deer of six hardwood species in an early successional hardwood forest of Pennsylvania, USA. Pin cherry was the most nutritious of the six species, with greater dry matter digestibility and digestible protein and lesser neutral detergent fiber. Areas exposed to browsing had less browse biomass of stems and leaves yet greater digestible protein, an effect driven by digestible protein of pin cherry. We found no effect of browsing on neutral detergent fiber or dry matter digestibility. Although deer browsing reduced biomass of the six hardwood species, it did not alter the nutritional capacity to support lactating females in the summer. Our results confirm that browsing limits tree regeneration and available browse and provides conservative conclusions on how deer can alter their diet quality.

Private land management is more important than public land in sustaining oaks in temperate forests in the eastern U.S.

Preserving the abundance and stocking of oaks (Quercus spp.) has become increasingly challenging in temperate hardwood forests of the eastern US in recent decades due to a remarkable shift in dominance to mesophytic species (e.g., red maple Acer rubrum). Studies have shown that efforts to sustain oaks while restraining maples yield limited success. Given that a significant portion of forestlands in the eastern U.S. are privately owned, it is critical to assess whether current forest management on cross-ownership forests can achieve those objectives. However, such assessments are rare. In this study, we employed a landscape modeling approach to investigate the long-term outcomes (i.e., 150-year forest composition and structure) of business-as-usual management and alternative management in a large, temperate hardwood forest landscape in Ohio, US. The business-as-usual management continues the current existing management practices, whereas the alternative management increases the pace and scale of forest management on both private and public lands to favor oaks. We compared the basal area and relative dominance for oaks (including Q. alba, Q. coccinea, Q. prinus, Q. rubra, and Q. velutina) and maples (including A. rubrum, A. saccharinum, and A. saccharum). Our results demonstrate that the implementation of business-as-usual management practices on both private and public lands may not effectively ensure the long-term sustainability of oak populations, but instead promote the proliferation of maple species over time. By contrast, alternative management on both private and public lands can effectively sustain oaks across a range of diameter classes while mitigating the growth of large, dominant maples. Our study emphasizes the influential role of private lands in driving oak-maple dynamics at the regional scale, as they can generate significant regional effects even when public lands continue with their business-as-usual management practices. Starting conditions based on landownership are crucial considerations for understanding these dynamics over time.

Climate calibration of the Spring Index model for more accurate broad-scale first leaf predictions

Phenological models are needed for forecasting plant and ecosystem responses to climate change. Due to a lack of considering local adaptation induced variations in climatic requirements of plant species for phenological development, traditional uniform/non-spatial models that cover broad geographic regions are susceptible to systematic prediction biases. This study presents a climate calibration method that incorporates climate adaptation patterns of plant species into a widely used Spring Index (SI) First Leaf (FL) model. Multi-year (2009-2021) phenological observation data for a most frequently observed shrub species(common lilac Syringa vulgaris) and a most frequently observed tree species(red maple Acer rubrum) in the eastern USA from the USA-National Phenology Network (USA-NPN) were used to develop and validate the calibrated models. Climatic gradients defined by latitudinal temperature variations were used to predict varied climatic requirements of the populations of each species. Prior to calibration, SI FL predictions showed consistent geographic biases and yielded large prediction errors (especially for red maple, RMSE = 30 d). Calibrated SI FL predictions yielded reduced errors (e.g. RMSE = 16 d for red maple) and were freed from significant geographic biases (α = 0.05) in all cases. The calibration method accounted for both intraspecific and interspecific variations, leading to more accurate broad-scale first leaf predictions for the species tested. The climate-calibrated SI FL allows for more accurate tracking of the onset of spring over extensive geographic areas and would support spatially explicit natural resource and environmental conservation efforts under climate change.

A three decade assessment of climate‐associated changes in forest composition across the north‐eastern USA

Summary Climate‐associated changes in forest composition have been widely reported, particularly where changes in abiotic conditions have resulted in high mortality of sensitive species and have disproportionately favoured certain species better adapted to these newer conditions. In the north‐eastern USA and south‐eastern Canada, few studies have examined climate‐related influences associated with forest composition, and none have considered broad‐scale changes over a long temporal (>25 years) period. We used US Forest Service Forest Inventory and Analysis data from 1983 to 2014 across four north‐eastern states (Maine, New Hampshire, New York and Vermont) to assess temporal and spatial changes in the occurrence and abundance of American beech Fagus grandifolia Ehrh, sugar maple Acer saccharum L., red maple Acer rubrum L. and birch Betula spp. saplings. We also tested the effects of biotic and abiotic factors on the distribution of the four studied deciduous species over the entire period examined. Occurrence and abundance of American beech have increased substantially over the past three decades, whereas the occurrence and abundance of three other deciduous species have decreased in all ecological provinces of the north‐eastern USA, except the Midwest Broadleaf ecological province. Consequently, a clear shift in species composition is currently underway in the beech‐maple‐birch (BMB) forests of the north‐eastern USA, with uncertain consequences for future ecosystem structure and function. In the studied region and over the entire period examined, the distribution of increased occurrence and abundance of beech relative to the three other deciduous species were associated with higher temperature and precipitation as well as higher conspecific basal area and dead tree basal area. Synthesis and applications. The change from beech‐maple‐birch forests to more beech‐dominated forests with beech encroachment to new forest areas across the north‐eastern USA may continue if higher intensity harvesting and disturbances (i.e. large‐scale canopy openings) do not occur. This would be a significant management concern as beech is associated with a widespread bark disease, is commercially less desirable, and can limit natural regeneration from other species. Our results emphasize the need for management strategies such as higher intensity harvesting methods, vegetation control and limiting browsing pressure to reduce beech dominance.

Recognizing cross‐ecosystem responses to changing temperatures: soil warming impacts pelagic food webs

The energy and materials that move across ecosystem boundaries influence food web structure and key ecosystem functions. Despite the acknowledged importance of such ecological subsidies, surprisingly little information is available regarding the role of environmental temperature in influencing subsidy quality and the response of the recipient ecosystem. We evaluated the impacts of temperature‐mediated changes in leaves from deciduous trees, an important subsidy from terrestrial to freshwater ecosystems, on both the producer‐based and detritivore‐based components of a pelagic pond food web in a field mesocosm experiment. We hypothesized that variation in leaf chemistry driven by increased soil temperature would alter both the quality of leaf subsidies and the pond response. We collected red maple Acer rubrum leaves from heated and ambient temperature plots from the long‐term soil warming experiment at the Harvard Experimental Forest and added them to 167‐l field mesocosms containing established plankton communities, creating ‘no leaf’, ‘ambient leaf’ and ‘heated leaf’ treatments during autumn 2012. We then monitored physical, chemical, and biological responses to treatments until the mesocosms froze six weeks later. Experimental soil warming altered the chemical composition of deciduous leaves, the physical and chemical environment of the aquatic ecosystems to which leaves were added, and the pelagic pond food webs as measured by community composition. Compared to leaves from ambient‐temperature soils, leaves from warmed soils initially resulted in lower water column phosphorus and dissolved organic carbon, reducing bacterial densities. However, the diminished carbon and phosphorus resulting from soil warming also increased light availability that ultimately stimulated cladoceran zooplankton relative to ambient‐temperature leaves. Our results suggest that changes in temperature can alter ecological subsidies in unanticipated ways, and suggest that accurately predicting the potential consequences of climate change will require conducting research across ecosystem boundaries.

Testing a growth efficiency hypothesis with continental-scale phenological variations of common and cloned plants

Variation in the timing of plant phenology caused by phenotypic plasticity is a sensitive measure of how organisms respond to weather and climate variability. Although continental-scale gradients in climate and consequential patterns in plant phenology are well recognized, the contribution of underlying genotypic difference to the geography of phenology is less well understood. We hypothesize that different temperate plant genotypes require varying amount of heat energy for resuming annual growth and reproduction as a result of adaptation and other ecological and evolutionary processes along climatic gradients. In particular, at least for some species, the growing degree days (GDD) needed to trigger the same spring phenology events (e.g., budburst and flower bloom) may be less for individuals originated from colder climates than those from warmer climates. This variable intrinsic heat energy requirement in plants can be characterized by the term growth efficiency and is quantitatively reflected in the timing of phenophases-earlier timing indicates higher efficiency (i.e., less heat energy needed to trigger phenophase transitions) and vice versa compared to a standard reference (i.e., either a uniform climate or a uniform genotype). In this study, we tested our hypothesis by comparing variations of budburst and bloom timing of two widely documented plants from the USA National Phenology Network (i.e., red maple-Acer rubrum and forsythia-Forsythia spp.) with cloned indicator plants (lilac-Syringa x chinensis 'Red Rothomagensis') at multiple eastern US sites. Our results indicate that across the accumulated temperature gradient, the two non-clonal plants showed significantly more gradual changes than the cloned plants, manifested by earlier phenology in colder climates and later phenology in warmer climates relative to the baseline clone phenological response. This finding provides initial evidence supporting the growth efficiency hypothesis, and suggests more work is warranted. More studies investigating genotype-determined phenological variations will be useful for better understanding and prediction of the continental-scale patterns of biospheric responses to climate change.

Numerical response of birds to an irruption of elm spanworm ( Ennomos subsignarius [Hbn.]; Geometridae: Lepidoptera) in old-growth forest of the Appalachian Plateau, USA

Populations of forest birds were studied during two years of an outbreak of the elm spanworm Ennomus subsignarius (Hbn.) in a silviculturally unmanaged, old-growth conifer–northern hardwood forest on the Appalachian Plateau, PA. Canopy defoliation of hardwoods (mostly American beech Fagus grandifolia and red maple Acer rubrum) increased by at least 50% during the local peak of the outbreak (1993); territorial densities of birds were the highest (15% greater) during the regional peak of the outbreak (1994). Compared to a nearby but uninfested forest of similar age and composition, total bird abundance was as much as 22–33% higher at sites with extensive spanworm defoliation. In addition to canopy gleaners, several other foraging guilds exhibited one or more significant numerical responses to outbreak location or intensity, including bark foraging, understory gleaning, ground foraging, and pursuing species. Like other irruptions of forest Lepidoptera, populations of arboreal canopy-gleaning Parulinae (the warblers D. magnolia, D. fusca) were especially prone to fluctuate during this geometrid irruption.

Electrical resistance and stem water relations in Verticillium‐infected red maple1

AbstractAn inverse relationship exists between stem water potential and electrical resistance (ER) in healthy red maple Acer rubrum L. (r = ‐ .93 to r = ‐ .98). Stem ER of red maple seedlings was measured at 1 to 2 day intervals during a 14 week course of infection by Verticillium dahliae Klebahn. No significant differences (P = .05) in ER were found between moderately to severely infected and control plants, although stem water potential of infected plants was significantly lower than the control plants. In plants which displayed only slight if any symptoms and in which no significant change in stem water potential occurred, ER of the infected plants was significantly lower than that of the control plants.

Forest composition at varying distances from a coal-burning power plant

Examination of the effects of sulphurous emissions from a coal-burning power plant on the vegetation of a mixed oak forest with white pine Pinus strobus L. and hemlock Tsuga canadensis (L.) Carr revealed that species diversity and importance values of certain species were inversely related to distance from the source of emission. Diversity and importance of white pine Pinus strobus L. and sweet birch Betula lenta L. increased with distance whereas the importance of white oak Quercus alba L. and red maple Acer rubrum L. decreased. Differences with distance were greater downwind than upwind. The data fitted hyperbolic equations using the reciprocal of distance from the emission source. Species richness and diversity were more sensitive indicators of pollution damage than growth assessments of individual overstorey species or groups of species.

Attractiveness to Nitidulidae (Coleoptera) of Natural Attrahents of Tree and Fungus Origin Supplemented with Vinegar and Water in an Appalachian Hardwood Foresest1

A feeder station was designed and tested to draw matinhabiting Nitidulidae (Coleoptera) to surfaces on feeder blocks where they can be counted or collected alive for subsequent testing to determine if they were carrying spores of the oak wilt fungus, Ceratocyslis fagacearum (Bretz) Hunt. Daily observations were made on the number and genera of Nitidulidae attracted to the fungus-inoculated and non inoculated red oak, Quercus rubra L., and red maple Acer rubrum L., feeder blocks kept moist with water or vinegar for 12 days in August ]965. More than twice as many nitidulids were observed on oak blocks than on maple blocks. Blocks moistened with vinegar attracted greater numbers of Carpophilus , the most abundant genus, than blocks moistened with water. Larger numbers of this genus were observed on blocks inoculated with C. pluriannulata (Hedge.) C. Moreau, a fungus closely related to C. fagacearum but nonpathogenic, than on the noninocuated blocks. Few Carpophilus spp., Stelidota sp., and Coleoptems spp. were found on blocks inoculated with Penicillium sp.

Natural Regeneration of Southern White Cedar

Although locally a natural resource of great importance, southern white cedar Chama~ecyparis thyoides has remained one of our least known forest trees. Aside from brief studies by Mohr (i899), Pinchot (i899), and Krinbill (19I5), all very limited as to data, little has been done to discover the silvical characteristics of this valuable timber tree of the coastal swamps. Consequently when the Appalachian Forest Experiment Station, in cooperation with the State Foresters of Virginia, North Carolina, and New Jersey, initiated a general study 2 during the past year, facts were discovered about southern white cedar that should be of interest to both the silviculturist and the ecologist. In this brief preliminary account of these investigations it will be impossible to more than touch upon the high lights. A more detailed report will appear at a later date. Although the southern white cedar is fastidious in respect to its habitat requirements it has a great variety of associates. This variety may be indicated by mentioning only some of the more important examples in different latitudinal parts of its range: in the northern part, as far south as New Jersey, pitch pine Pinus rigida, black gum Nyssa sylvatica, gray birch Betula populifolia and red maple Acer rubrum; in Virginia, North Carolina and South Carolina, pond pine Pinus serotina, red maple, water gum Nyssa biflora, white bay Magnolia glauca and bald cypress Taxodium distichum; in South Carolina, loblolly bay Gordonia lasianthus; in Florida and Alabama, titi Cliftonia monophylla; in Florida, Georgia, Alabama, and Mississippi, water gum, red maple, white bay and slash pine Pinus caribaea. Nevertheless, southern white cedar exhibits a strong tendency to grow in pure evenaged stands throughout the greater part of its range. A marked characteristic of such stands is a dense tangle of shrubs and vines underneath, which makes passage difficult. The hardwood-cypress swamps surrounding the white cedar glades of the Dismal Swamp and Albemarle Sound regions of North Carolina are generally underlain by a clay or sandy clay subsoil. In the cedar glades the pro-