Multiple Controls of Cliff-Edge Distribution Patterns of Thuja Occidentalis and Acer Saccharum at The Stage of Seedling Recruitment

1991 ◽  
Vol 79 (1) ◽  
pp. 183 ◽  
Author(s):  
R. M. Bartlett ◽  
R. J. Reader ◽  
D. W. Larson
Ecography ◽  
1992 ◽  
Vol 15 (3) ◽  
pp. 262-266 ◽  
Author(s):  
Uta Matthes-Sears ◽  
Christoph Neeser ◽  
Douglas W. Larson

2018 ◽  
Vol 12 (3–4) ◽  
pp. 75-94 ◽  
Author(s):  
Z. Barkaszi ◽  
◽  
I. Zagorodniuk ◽  

1990 ◽  
Vol 68 (11) ◽  
pp. 2371-2380 ◽  
Author(s):  
U. Matthes-Sears ◽  
D. W. Larson

Thuja occidentalis L. and Acer saccharum Marsh, show mutually exclusive distribution patterns along forested cliff edges of the Niagara Escarpment; T. occidentalis occurs at the cliff edge and on the cliff face, whereas A. saccharum occurs with increasing frequency away from the cliff edge. To reveal the controls of such patterns, seasonal and diurnal courses of net photosynthesis (Pn), stomatal conductance (gs), and xylem water potential were measured in situ and related to fluctuations in light, temperature, and moisture. For each species, saplings growing in the cedar zone near the cliff edge were compared with saplings growing in the deciduous forest zone farther from the cliff edge on the plateau. The carbon uptake of both species was most often limited by light; limitation by temperature, atmospheric, or soil moisture was rare. Acer saccharum was slightly better adapted than T. occidentalis to growth at the low light levels in both zones because of a greater light-use efficiency. During severe drought, both species showed reductions in Pn and gs when growing near the cliff edge. In the deciduous forest, in contrast, Pn of T. occidentalis, but not A. saccharum, was significantly reduced, suggesting that A. saccharum may outcompete T. occidentalis for water. In the spring and fall, T. occidentalis had higher Pn and gs in the deciduous forest than at the cliff edge. However, all differences in gas exchange rates between trees in the deciduous forest and at the cliff edge were small and relatively rare. During most of the growing season, Pn and gs differed little between saplings in the two zones. This suggests that the pattern of abundance is not controlled to a substantial degree by carbon gain at the sapling stage. Key words: photosynthesis, water potential, Acer saccharum, Thuja occidentalis, plant zonation, cliff–forest ecotone.


2005 ◽  
Vol 35 (4) ◽  
pp. 978-989 ◽  
Author(s):  
John P Caspersen ◽  
Megan Saprunoff

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.


1990 ◽  
Vol 68 (9) ◽  
pp. 1931-1941 ◽  
Author(s):  
R. M. Bartlett ◽  
U. Matthes-Sears ◽  
D. W. Larson

In cliff-edge forests along the Niagara Escarpment, an array of species, including Thuja occidentals, is restricted to the cliff edge while different species, including Acer saccharum, are increasingly dominant away from the cliff on the plateau. This paper presents detailed analyses of 13 components of the physical environment, measured over an 18-month period, as they change across the plateau and towards the cliff edge. Statistically significant differences between the cliff-edge habitat and the adjacent deciduous forest were found in most of the 13 variables, and the results indicate a strong environmental gradient between the cliff edge and deciduous forest habitats. Lower and more rapidly fluctuating soil moisture levels combined with low photosynthetically active radiation at the cliff edge suggest that conditions there are frequently more severe for plants than in the deciduous forest in summer. Additionally, the cliff edge was snow free during the winter and the soils were frozen for a more protracted period than the deciduous forest soils. Soil and litter depths decreased significantly from the deciduous forest toward the cliff edge. The effects of these differences are discussed with reference to the characteristics of species that dominate the deciduous and coniferous cliff-edge zones. Key words: cliff, gradient, Thuja occidentalis, Acer saccharum, microclimate, Niagara Escarpment.


2008 ◽  
Vol 38 (6) ◽  
pp. 1634-1645 ◽  
Author(s):  
Alejandro A. Royo ◽  
Walter P. Carson

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.


2020 ◽  
Vol 13 (2) ◽  
pp. 112-121
Author(s):  
Sudiyar . ◽  
Okto Supratman ◽  
Indra Ambalika Syari

The destructive fishing feared will give a negative impact on the survival of this organism. This study aims to analyze the density of bivalves, distribution patterns, and to analyze the relationship of bivalves with environmental parameters in Tanjung Pura village. This research was conducted in March 2019. The systematic random system method was used for collecting data of bivalves. The collecting Data retrieval divided into five research stasions. The results obtained 6 types of bivalves from 3 families and the total is 115 individuals. The highest bivalve density is 4.56 ind / m², and the lowest bivalves are located at station 2,1.56 ind / m²,  The pattern of bivalve distribution in the Coastal of Tanjung Pura Village is grouping. The results of principal component analysis (PCA) showed that Anadara granosa species was positively correlated with TSS r = 0.890, Dosinia contusa, Anomalocardia squamosa, Mererix meretrix, Placamen isabellina, and Tellinella spengleri were positively correlated with currents r = 0.933.


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