Direct and indirect effects of a dense understory on tree seedling recruitment in temperate forests: habitat-mediated predation versus competition

2008 ◽  
Vol 38 (6) ◽  
pp. 1634-1645 ◽  
Author(s):  
Alejandro A. Royo ◽  
Walter P. Carson
Keyword(s):  
Indirect Effects ◽  
Vegetation Cover ◽  
Acer Saccharum ◽  
Resource Competition ◽  
Seedling Recruitment ◽  
Plant Cover ◽  
Acer Rubrum ◽  
Fagus Grandifolia ◽  
Tree Seedling ◽  
The Impact

In forests characterized by a dense woody and herbaceous understory layer, seedling recruitment is often directly suppressed via interspecific competition. Alternatively, these dense layers may indirectly lower tree recruitment by providing a haven for seed and seedling predators that prey on neighboring plant species. To simultaneously test for resource competition and indirect, habitat-mediated effects, we factorially manipulated understory plant cover (removed versus intact) and predation (exclosures versus controls) at three forested sites. We found that vegetation cover created privileged foraging areas that increased seed removal and seedling predation rates. Predator preference was directly related to seed size with larger seeded species including Prunus serotina Ehrh. and Fagus grandifolia Ehrh. removed more readily than smaller seeded species such as Fraxinus americana L. We found strong species-specific evidence for habitat-mediated indirect effects; establishment of P. serotina and Acer saccharum Marsh.was significantly lower under an intact hay-scented fern ( Dennstaedtia punctilobula (Michx.) T. Moore) canopy when small mammals were present. Competition also played a strong role; both P. serotina and Acer rubrum L. survival as well as A. rubrum emergence were reduced under a fern canopy with or without seed predators. The impact of habitat-mediated indirect effects and resource competition appear to vary predictably based upon predator preferences and differences in the timing of woody seed dispersal and germination relative to vegetation cover phenology. Overall, our results suggest that habitat-mediated indirect effects may be common and occur wherever vegetation provides the potential for creating privileged foraging areas.

Variation in vegetation cover and seedling performance of tree species in a forest-savanna ecotone

2019 ◽  
Vol 35 (2) ◽  
pp. 74-82 ◽  
Author(s):  
Hamza Issifu ◽  
George K. D. Ametsitsi ◽  
Lana J. de Vries ◽  
Gloria Djaney Djagbletey ◽  
Stephen Adu-Bredu ◽  
...  
Keyword(s):  
Vegetation Cover ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Tree Cover ◽  
First Year ◽  
Transplant Experiment ◽  
Tree Seedling ◽  
Savanna Woodland ◽  
Specific Effects ◽  
Species Specific

AbstractDifferential tree seedling recruitment across forest-savanna ecotones is poorly understood, but hypothesized to be influenced by vegetation cover and associated factors. In a 3-y-long field transplant experiment in the forest-savanna ecotone of Ghana, we assessed performance and root allocation of 864 seedlings for two forest (Khaya ivorensis and Terminalia superba) and two savanna (Khaya senegalensis and Terminalia macroptera) species in savanna woodland, closed-woodland and forest. Herbaceous vegetation biomass was significantly higher in savanna woodland (1.0 ± 0.4 kg m−2 vs 0.2 ± 0.1 kg m−2 in forest) and hence expected fire intensities, while some soil properties were improved in forest. Regardless, seedling survival declined significantly in the first-year dry-season for all species with huge declines for the forest species (50% vs 6% for Khaya and 16% vs 2% for Terminalia) by year 2. After 3 y, only savanna species survived in savanna woodland. However, best performance for savanna Khaya was in forest, but in savanna woodland for savanna Terminalia which also had the highest biomass fraction (0.8 ± 0.1 g g−1 vs 0.6 ± 0.1 g g−1 and 0.4 ± 0.1 g g−1) and starch concentration (27% ± 10% vs 15% ± 7% and 10% ± 4%) in roots relative to savanna and forest Khaya respectively. Our results demonstrate that tree cover variation has species-specific effects on tree seedling recruitment which is related to root storage functions.

Physical and historical determinants of the pre- and post-settlement forests of northwestern Pennsylvania

2003 ◽  
Vol 33 (9) ◽  
pp. 1683-1697 ◽  
Author(s):  
Gordon G Whitney ◽  
Joseph P DeCant
Keyword(s):  
19Th Century ◽  
Acer Saccharum ◽  
Petroleum Industry ◽  
Acer Rubrum ◽  
Fagus Grandifolia ◽  
Quercus Alba ◽  
Old Field ◽  
European Settlement ◽  
Northern Portion ◽  
The 19Th Century

Our analysis of the early land survey records and more recent U.S. Forest Service inventory data documents the changing nature of northwestern Pennsylvania's forests following European settlement. Initially, the northern portion of the four-county study area was dominated by forests of Fagus grandifolia Ehrh. and Acer saccharum Marsh. associated with the richer, finer-textured soils of the rolling Glaciated Appalachian Plateau. Up to 80% of the region was cleared for farming in the 19th century. Marginal farmland was abandoned and reverted to forests in the 20th century. Fires and leached, nutrient-poor soils favored the dominance of Quercus spp. and Castanea dentata (Marsh.) Borkh. in the presettlement forests of the rugged Unglaciated Appalachian Plateaus to the south. The rough nature of the terrain discouraged the early clearance of the plateaus' forests. The advent of the petroleum industry and its insatiable demand for barrels in the 19th century, however, assured the selective removal of the larger (>20 in. (50 cm) DBH) Quercus alba L. from the region's woods. The increasing homogeneity of northwestern Pennsylvania's forests today is due to the sharp decline of the more distinctive indicator species and the rise of a number of opportunistic old-field or gap species, notably Prunus serotina Ehrh. and Acer rubrum L.

La végétation forestière du delta de Lanoraie, Québec

1991 ◽  
Vol 69 (8) ◽  
pp. 1839-1852 ◽  
Author(s):  
L. Lamontagne ◽  
C. Camiré ◽  
C. Ansseau
Keyword(s):  
Populus Tremuloides ◽  
Acer Saccharum ◽  
Abies Balsamea ◽  
Acer Rubrum ◽  
Fagus Grandifolia ◽  
The Other ◽  
Moisture Regime ◽  
Acidic Ph ◽  
Mature Trees ◽  
Forest Sites

The vegetation and the soil characteristics of the sandy terraces of the Lanoraie Delta, Quebec, were sampled at 84 forest sites using the methods of Whittaker and Canada Soil Information System. The ordination results show that the soil moisture regime (xeric–hydric) and the pH (3.5–5.0) are the main factors responsible for the spatial distribution of the vegetation. When these results (ordination analysis) and those of the cluster analysis are superimposed, the relationship between the five vegetation groups studied and particular ecological conditions can be seen. Thus, two groups of vegetation dominated by conifers are found in the middle of the terraces. One of these is dominated by Tsuga canadensis and the other by Abies balsamea and Picea rubens. These two groups are found on podzolic, gleyed soils with a mounded microrelief, which are strongly acidic (pH < 3.5) and have a hydric–mesic moisture regime. The remaining three vegetation groups are dominated by deciduous species. Among these, two groups arise from human activities such as logging or farming. One of these is dominated by Fagus grandifolia, Acer saccharum, Acer rubrum, and Quercus rubra and is composed of mature trees. The other is dominated by Pinus strobus, Polulus grandidentata, Populus tremuloides, or Betula papyrifera and is composed of young trees. These two types occupy the edge of the terraces where the topography is flat and the soil podzolic with a moderately to slightly acidic pH (4.0–5.0) and a xeric–mesic moisture regime. Finally the third group, dominated by Acer rubrum, is found on medium acidic (pH = 4.0), gleyed soils with a hydric–mesic moisture regime. This study shows that Acer rubrum is the best suited species for sandy, acidic, and nutrient-poor sites of the Lanoraie Delta. Key words: Lanoraie Delta, multivariate analysis, vegetation classification, Acer rubrum.

scholarly journals Insect herbivores increase mortality and reduce tree seedling growth of some species in temperate forest canopy gaps

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3102 ◽  
Author(s):  
Nathan P. Lemoine ◽  
Deron E. Burkepile ◽  
John D. Parker
Keyword(s):  
Tree Species ◽  
Forest Canopy ◽  
Acer Rubrum ◽  
Fagus Grandifolia ◽  
Tree Seedlings ◽  
Insect Herbivores ◽  
Pioneer Species ◽  
Tree Seedling ◽  
Selective Predation ◽  
Forest Diversity

Insect herbivores help maintain forest diversity through selective predation on seedlings of vulnerable tree species. Although the role of natural enemies has been well-studied in tropical systems, relatively few studies have experimentally manipulated insect abundance in temperate forests and tracked impacts over multiple years. We conducted a three-year experiment (2012–2014) deterring insect herbivores from seedlings in new treefall gaps in deciduous hardwood forests in Maryland. During this study, we tracked recruitment of all tree seedlings, as well as survivorship and growth of 889 individual seedlings from five tree species:Acer rubrum,Fagus grandifolia,Fraxinusspp.,Liriodendron tulipifera, andLiquidambar styraciflua. Insect herbivores had little effect on recruitment of any tree species, although there was a weak indication that recruitment ofA. rubrumwas higher in the presence of herbivores. Insect herbivores reduced survivorship ofL. tulipifera, but had no significant effects onA. rubrum,Fraxinusspp.,F. grandifolia, orL. styraciflua. Additionally, insects reduced growth rates of early pioneer speciesA. rubrum,L. tulipifera, andL. styraciflua, but had little effect on more shade-tolerant speciesF. grandifoliaandFraxinusspp. Overall, by negatively impacting growth and survivorship of early pioneer species, forest insects may play an important but relatively cryptic role in forest gap dynamics, with potentially interesting impacts on the overall maintenance of diversity.

Tree seedling growth and mortality responses to manipulations of calcium and aluminum in a northern hardwood forest

2002 ◽  
Vol 32 (6) ◽  
pp. 954-966 ◽  
Author(s):  
Richard K Kobe ◽  
Gene E Likens ◽  
Christopher Eagar
Keyword(s):  
Acer Saccharum ◽  
Abies Balsamea ◽  
Fagus Grandifolia ◽  
Diameter Growth ◽  
Tree Seedlings ◽  
Betula Alleghaniensis ◽  
Hubbard Brook Experimental Forest ◽  
Tree Seedling ◽  
Soil Calcium ◽  
Dependent Growth

To assess potential forest compositional responses to exchangeable soil calcium (Caexch) and aluminum (Alexch), we characterized light-dependent growth and mortality of tree seedlings under amendments of CaCl2 and AlCl3 at Hubbard Brook Experimental Forest (HBEF), New Hampshire, U.S.A. Seedlings of Acer saccharum Marsh., Fagus grandifolia Ehrh., Betula alleghaniensis Britton, Abies balsamea (L.) Mill., and Picea rubens Sarg. were transplanted into field plots, which were randomly assigned to control, CaCl2, or AlCl3 treatments and stratified across <1 to 35% full sun. Acer saccharum and P. rubens exhibited significantly higher mortality in Al-amended than Ca-amended or control plots. Acer saccharum showed significant increases in relative diameter growth in Ca-amended plots versus controls; all other species showed nonsignificantly higher relative diameter growth under Ca amendments. We incorporated significant seedling responses into a model of forest dynamics (SORTIE) to assess potential changes in species composition under Alexch increases and Caexch losses. SORTIE predicts that further increases in Alexch would have negligible effects on canopy composition within 200 years but that the estimated Caexch depleted from HBEF between 1968 and 1995 and its influence on seedling dynamics could lead to substantial decreases in A. saccharum canopy dominance within a single forest generation (<125 years).

Using witness trees to assess forest change in southeastern Ohio

2001 ◽  
Vol 31 (10) ◽  
pp. 1708-1718 ◽  
Author(s):  
James M Dyer
Keyword(s):  
Acer Saccharum ◽  
Acer Rubrum ◽  
Fagus Grandifolia ◽  
Forest Composition ◽  
Significant Shift ◽  
Quercus Alba ◽  
Forest Change ◽  
Composition And Structure ◽  
Successional Species ◽  
Witness Trees

In 1787, the U.S. Congress authorized the sale of the "Ohio Company Purchase", ca. 5000 km2 in Appalachian Ohio. The land was surveyed using a township and range system shortly thereafter. Data on >5600 witness trees were transcribed from the survey records, and witness tree locations were plotted on a digital map. This information was used to evaluate presettlement forest composition and structure and to investigate vegetation-site relationships before widespread alteration of the forests had taken place. Presettlement conditions were compared with present conditions using forest inventory and analysis (FIA) data. Two hundred years ago, the forests of southeastern Ohio were dominated by large individuals of Quercus alba L., Carya Nutt. spp., Quercus velutina Lam., and Fagus grandifolia Ehrh. These four taxa accounted for 74% of all witness trees. Although almost 70% of the region is forested today, the second-growth forest has witnessed a decrease in Quercus and Carya and an increase in Acer saccharum Marsh., Acer rubrum L., and many early successional species in smaller size classes. Despite the significant shift in forest composition and structure, species in general seem to be occupying similar positions in the present-day landscape compared with the presettlement forest; topographic variables most strongly control species occurrence in this landscape.

Seedling recruitment in a northern temperate forest: the relative importance of supply and establishment limitation

2005 ◽  
Vol 35 (4) ◽  
pp. 978-989 ◽  
Author(s):  
John P Caspersen ◽  
Megan Saprunoff
Keyword(s):  
Acer Saccharum ◽  
Temperate Forest ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Abies Balsamea ◽  
Common Species ◽  
Fagus Grandifolia ◽  
Betula Alleghaniensis ◽  
Recruitment Failure ◽  
Niche Differences

We quantified supply and establishment limitation as components of seedling recruitment for five species common to the temperate forests of central Ontario. Establishment limitation was the primary cause of recruitment failure for the three most common species: Acer saccharum Marsh., Betula alleghaniensis Britt., and Tsuga canadensis (L.) Carrière. The main barrier to establishment (including germination and seedling emergence) was a lack of suitable substrates, rather than a lack of light. Supply limitation, on the other hand, was the primary cause of recruitment failure for two less common species, Abies balsamea (L.) Mill. and Fagus grandifolia Ehrh. The cause of supply limitation was a lack of parent trees, in the case of A. balsamea, and low fecundity, in the case of F. grandifolia. Our results suggest that niche differences (i.e., germination requirements) are more important than dispersal in structuring temperate forest communities. Our results also suggest that availability of suitable substrates is the primary factor limiting seedling recruitment following logging.

La végétation des contreforts des Laurentides : une analyse des gradients écologiques et du niveau successionnel des communautés

1990 ◽  
Vol 68 (2) ◽  
pp. 391-401 ◽  
Author(s):  
Sylvie Gauthier ◽  
Daniel Gagnon
Keyword(s):  
Acer Saccharum ◽  
Acer Rubrum ◽  
Ecological Factors ◽  
High Elevation ◽  
Fagus Grandifolia ◽  
Community Type ◽  
Two Factors ◽  
Community Types ◽  
Topographic Positions ◽  
Vegetation Variation

The forest vegetation of the foothills of the Laurentians was studied to determine which ecological factors are most strongly correlated with vegetation variation. Vegetation and ecological factors were sampled within 78 plots distributed systematically on 19 transects. Ordination and classification analyses show that soil moisture and richness, two factors strongly associated to topographical variations, are the ecological factors that best explain vegetation distribution. Eleven community types were identified. Oligotrophic–xeric community types, characterized by Pinus strobus and Quercus rubra, are generally found in sites at high elevation, where soils are thin, well drained and nutrient poor. The Acer saccharum community types, of the mesotrophic–mesic group, are situated at the base of slopes with deep, rich soils. Fagus grandifolia, Acer rubrum, and Tsuga canadensis characterize a third group of oligotrophic–mesic community types, found on sites with relatively poorly drained and nutrient-poor soils, in topographic positions intermediate to the first two groups. A community type successionnal status index, based on the homogeneity and similarity of the tree and sapling strata, shows that natural and anthropogenic disturbances are also responsible for part of the vegetation variation. Hemlock and beech forests are the most successionnally advanced community types of the oligotrophic–mesic group. On richer soils fed by seepage, the maple–hickory community type is also relatively stable. These results contribute to the ongoing discussion about the eventual outcome of succession on mesic sites in northeastern North America.

scholarly journals AN ASSESSMENT OF DISTURBANCE EFFECTS ON PLANT COVER OF NUMTO NATURAL PARK (KHANTY-MANSIYSK AUTONOMOUS OKRUG - UGRA)

2020 ◽  
pp. 81-89
Author(s):  
D. V. Moskovchenko ◽  
S. P. Aref’ev ◽  
V. A. Glazunov ◽  
I. V. Filippov
Keyword(s):  
Vegetation Cover ◽  
Oil And Gas ◽  
Plant Cover ◽  
Oil Extraction ◽  
Oil Field ◽  
Nature Management ◽  
Field Development ◽  
Natural Park ◽  
Oil Deposits ◽  
The Impact

The Numto Natural Park, Khanty-Mansi Autono-mous Okrug - Yugra, Russia, has recently attracted the attention of environmental organizations due to oil extraction operations in its territory. This paper presents the study of the vegetation cover dynamics and the assessment of natural and anthropogenic disturbances of Numto’s ecosystems. Due to the development of oil deposits, more than 60 adventitious plant species arrived to the park, and the synan-thropization index reached 26.4%. Tree rings showed the predominant influence of the climatic and pyrogenic components on the growth of trees. The technogenic impact that had occurred in the 1990s gave a spasmodic increase in cedar growth in the disturbed areas in the form of abnormal hard streaks. Later on, the impact of technogenic factors on the wood growth waned. Satellite imagery helped to determine changes in the vegetation cover. From 2011 to 2018, the area of disturbed sites doubled while the length of infield roads and pipelines increased by 5.7 times. The area of burnt fire sites increased manifold; how-ever, fires occurred at a considerable distance from the oil extraction sites and were of natural origin. Currently, the disturbed ecosystems, including burnt fire sites and fire-damaged ecosystems, occupy 2.1% of the oil deposits area, and the area of pyrogenic disturbances is larger than the area of technogenic ones. Compared to the oil and gas fields in the adjacent areas, the level of disturbance in the Numto Natural Park can be considered low. Since deer pastures were not disturbed by the oil extraction operations, the traditional nature management remains possible. Further oil field development requires ongoing monitoring of the ecosystem condition.

scholarly journals Forest Disturbance Types and Current Analogs for Historical Disturbance-Independent Forests

Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 136
Author(s):  
Brice B. Hanberry
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Forest Disturbance ◽  
Acer Rubrum ◽  
Fagus Grandifolia ◽  
Eastern United States ◽  
Red Maple ◽  
Disturbance Regimes ◽  
Historical Distribution ◽  
Lower Peninsula

Forest classifications by disturbance permit designation of multiple types of both old growth forests and shorter-lived forests, which auto-replace under severe disturbance, and also identification of loss of the disturbance type and associated forest. Historically, fire and flooding disturbance regimes, or conversely, infrequent disturbance, produced unique forests such as disturbance-independent forests of American beech (Fagus grandifolia), eastern hemlock (Tsuga canadensis), and sugar maple (Acer saccharum) in the Eastern United States. However, disturbance has changed to primarily frequent mechanical overstory disturbance, resulting in novel forests. To demonstrate the transition to no-analog forests after disturbance change, I compared historical tree surveys (ca. 1837 to 1857) to current surveys in the Northern Lower Peninsula of Michigan. To establish widespread disturbance change effects, I also located where beech and hemlock are currently most abundant throughout the Eastern US compared to historical distribution of beech–hemlock forests. In the Northern Lower Peninsula of Michigan, beech and hemlock historically were about 30% of all trees, but currently, beech and hemlock are 2% of all trees. Red maple (Acer rubrum) increased from 1% to 11% of all trees and aspen (Populus) increased from 2% to 13% of all trees. The squared-chord difference between historical and current surveys was 0.40, or dissimilar forests. Areas with ≥20% beech and hemlock or ≥15% of either species decreased from about 52 million to 6 million hectares, with current distribution restricted to the Northeastern US. Current forests are dissimilar to historical forests, and this transition appears to be driven by disturbance regimes without historical analogs. Disturbance change may provide perspective in forest management for climate change.

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