A function describing all-sized trunk diameter distribution in warm-temperate rain forests

1988 ◽  
Vol 101 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Takashi Kohyama
Tropics ◽  
1996 ◽  
Vol 6 (4) ◽  
pp. 383-392 ◽  
Author(s):  
Takashi KOHYAMA ◽  
Shin-ichiro AIBA

2013 ◽  
Vol 88 (3) ◽  
pp. 701-744 ◽  
Author(s):  
Peter J. Grubb ◽  
Peter J. Bellingham ◽  
Takashi S. Kohyama ◽  
Frida I. Piper ◽  
Alfredo Valido

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 135 ◽  
Author(s):  
Justin Morgenroth ◽  
David Nowak ◽  
Andrew Koeser

Background and Objectives: The structural diversity of an urban forest affects ecosystem service provision, and can inform management, planning, as well as policy. Trunk diameter at breast height (DBH) is amongst the most common measures of tree structure due to its ease of measurement and strong relationships with other structural and non-structural urban forest characteristics. Materials and Methods: In this study, the DBH distributions of urban forests are summarised for 38 American cities with a combined population of over 30 million people and a range of geographic, climatic, and demographic conditions. The Anderson–Darling (AD) test was used to test the hypothesis that all DBH distributions came from a common population. Moreover, structural diversity was compared using the Shannon–Wiener index. Results: The AD test results failed to identify any statistically significant differences in DBH distributions. However, qualitatively, the DBH distributions have two primary forms, which have important functional, management, and planning implications. The vast majority of cities have an exponentially inverse-proportional distribution, such that the proportion of trees in each successively larger DBH class decreases exponentially. The Shannon–Wiener index indicates an uneven DBH distribution in the cities with an exponentially inverse-proportional diameter distribution; these cities are dominated by trees in the smallest diameter class. Potential explanations for a large proportion of trees in the smallest diameter classes include a large number of small, naturally regenerating trees; a preference for smaller trees in urban areas; or a recent increase in tree planting efforts. Conclusions: Despite no statistical differences in DBH distributions for the 38 study cities, the functional, management, and planning implications will differ considerably.


2008 ◽  
Vol 35 (2) ◽  
pp. 243-251 ◽  
Author(s):  
RAGNAR K. KINZELBACH

The secretarybird, the only species of the family Sagittariidae (Falconiformes), inhabits all of sub-Saharan Africa except the rain forests. Secretarybird, its vernacular name in many languages, may be derived from the Arabic “saqr at-tair”, “falcon of the hunt”, which found its way into French during the crusades. From the same period are two drawings of a “bistarda deserti” in a codex by the Holy Roman Emperor Frederick II (1194–1250). The original sketch obviously, together with other information on birds, came from the court of Sultan al-Kâmil (1180–1238) in Cairo. Careful examination led to an interpretation as Sagittarius serpentarius. Two archaeological sources and one nineteenth century observation strengthened the idea of a former occurrence of the secretarybird in the Egyptian Nile valley. André Thevet (1502–1590), a French cleric and reliable research traveller, described and depicted in 1558 a strange bird, named “Pa” in Persian language, from what he called Madagascar. The woodcut is identified as Sagittarius serpentarius. The text reveals East Africa as the real home of this bird, associated there among others with elephants. From there raises a connection to the tales of the fabulous roc, which feeds its offspring with elephants, ending up in the vernacular name of the extinct Madagascar ostrich as elephantbird.


2012 ◽  
Vol 28 (5) ◽  
pp. 437-443 ◽  
Author(s):  
Terrence P. McGlynn ◽  
Evan K. Poirson

Abstract:The decomposition of leaf litter is governed, in part, by litter invertebrates. In tropical rain forests, ants are dominant predators in the leaf litter and may alter litter decomposition through the action of a top-down control of food web structure. The role of ants in litter decomposition was investigated in a Costa Rican lowland rain forest with two experiments. In a mesocosm experiment, we manipulated ant presence in 50 ambient leaf-litter mesocosms. In a litterbag gradient experiment, Cecropia obtusifolia litter was used to measure decomposition rate constants across gradients in nutrients, ant density and richness, with 27 separate litterbag treatments for total arthropod exclusion or partial arthropod exclusion. After 2 mo, mass loss in mesocosms containing ants was 30.9%, significantly greater than the 23.5% mass loss in mesocosms without ants. In the litter bags with all arthropods excluded, decomposition was best accounted by the carbon: phosphorus content of soil (r2 = 0.41). In litter bags permitting smaller arthropods but excluding ants, decomposition was best explained by the local biomass of ants in the vicinity of the litter bags (r2 = 0.50). Once the microarthropod prey of ants are permitted to enter litterbags, the biomass of ants near the litterbags overtakes soil chemistry as the regulator of decomposition. In concert, these results support a working hypothesis that litter-dwelling ants are responsible for accelerating litter decomposition in lowland tropical rain forests.


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