Vertical profile and canopy organization in a mixed deciduous forest

Abstract

A combination of optical measurements of leaf heights and observations on litterfall provided a vertical and temporal description of the leaf community structure in a tall, Liriodendron forest on the Maryland coastal plain. Leaf area, mass, and number were bimodally distributed with height. Median leaf number occurs far below (7-8 m) and median leaf mass far above (22-23 m) the median leaf area (18-19 m). Tree species exhibited leaf stratification into 3 height levels: understory (0-10 m), mid canopy (10-25 m), and overstory (25-37 m). Species leaf area in litterfall was related to the species basal area, although representation of leaf number in litterfall was not correlated with stem numbers for species in the stand. Species also showed a clear phenological sequence of leaf fall.Abbreviations." LAD = Leaf Area Duration; LAI = Leaf Area Index; SLA = Specific Leaf Area.

Isotopic characteristics of canopies in simulated leaf assemblages

“…Average annual precipitation (MAP) in this area is 108 cm and the region is classified as a humid subtropical climate (Kö ppen classification by FAO GeoNetwork). This seasonally deciduous forest is dominated by Liriodendron tulipifera in the upper and mid-canopy, Fagus grandifolia in the lower mid-canopy and Carpinus caroliniana in the understory (Parker et al, 1989;Brown and Parker, 1994). Most foliage is produced during spring leaf flush when the canopy is open (Brown and Parker, 1994), although canopy closure of >99% light attenuation is reached at the height of the summer growing period.…”

“…In tropical closedcanopy forests most leaf biomass occurs in the upper canopy. Well-lit leaves have higher photosynthetic rates and have shorter life spans compared to more shaded leaves, although this is not always observed (Parker et al, 1989;Wright and Cannon, 2001;Santiago and Wright, 2007). Reich et al (1991) found, on a global scale, an inverse logarithmic relationship between leaf life span and net photosynthetic rate.…”

Land use change affects earthworm communities in Eastern Maryland, USA

“…The current landscape of SERC is a patchwork of several stages of old field succession and other land cover such as grass and buildings. Forests at SERC have been classified into the Tulip poplar association [6,7,18]. The most common tree species include tulip poplar (Liriodendron tulipifera), sweetgum (Liquidambar styraciflua), red maple (Acer rubrum), several oaks (Quercus spp.…”

The reflection of deciduous forest communities in leaf litter: implications for autochthonous litter assemblages from the fossil record

“…With few exceptions, however (Kunkel-Westphal and Kunkel 1979;Turnbull and Madden 1983;Carpenter and Horowitz 1988), these studies are concerned primarily with total litter mass and nutrient cycling and either they do not categorize foliage mass by species (Klinge and Rodrigues 1968;Bongers et al 1988;Dantas and Phillipson 1989) or they do not provide detailed information on the position of trees in the source forest (Coulter and Allaway 1979;Kunkel-Westphal and Kunkel 1979;Mayack et al 1989). A recent study by Parker et al (1989) is one of the first to investigate littersource forest relationships on a per-species basis, although the motivation was not for paleoecological analysis.…”