A trial was conducted in a 7-year old citrus orchard of the National Horticultural Research Institute, Nigeria, to investigate the effect of different levels of organo-mineral fertilizers as it affect the economic returns of sweet orange (Citrus sinensis L. Osbeck var. Agege 1). The treatments consisted of: (1). 10 tha Poultry 1 manure (PM), (2). 15 t ha PM, (3) 20 t ha-1 PM, (4). 0.45 t ha NPK...

Nurse plant facilitation in stressful environments can produce an environment with relatively low stress under its canopy. These nurse plants may produce the conditions promoting intense competition between coexisting species under the canopy, and canopies may establish stress gradients, where stress increases toward the edge of the canopy. Competition and facilitation on these stress gradients...

In this study, the structurally heterogeneous canopy of a 12-ha plot in an old-growth Douglas-fir forest was analyzed using three-dimensional (3-D) canopy modeling, geographic information system (GIS), and spatial statistics. Using this approach, we were able to depict how species composition and spatial distribution affect the 3-D structure of canopies. We were also able to slice the canopy an...

High intensity canopy height LIDAR data affords model-based estimation of tree locations. The analysis of spatial point patterns is a natural extension of this modeling capability. Identification of within-stand clusters (features) of trees deviating significantly in height from those of surrounding trees (clutter) is important for inventory and forest management purposes. We demonstrate a nonp...

Trees make our cities and urban areas more livable. provide many benefits, known as ecosystem services, to residents. Cities often management plans care for their trees increase the benefits provided by forests. These include goals tree cover. This study assessed cover in 300 Florida (U.S.A.) cities. Each city’s canopy coverage (a percentage of how much a city is covered leafy tops trees) was a...

The importance of lianas through time and their effect on tree reproduction are evaluated for the first time in a Southeast Asian Dipterocarp forest. We quantified flower and seed production by lianas and trees for 13 years, assessed liana loads in the crowns of all trees larger than 30 cm in diameter at breast height (1.3 m) in 2002 and 2014, and assessed levels of reproduction for the same tr...

Light models for vegetation canopies based on the turbid medium analogy are usually limited by the basic assumption of random foliage dispersion in the canopy space. The objective of this paper was to assess the effect of three possible sources of non-randomness in tree canopies on light interception properties. For this purpose, four threedimensional (3-D) digitized trees and four theoretical ...

To date, it is not clear which are the factors that most influence tropical forest recovery from hurricanes. Increased canopy openness and increased detritus (debris) deposition are two of the most likely factors, but due to their simultaneous occurrence during a hurricane, their relative effects cannot be separated without a manipulative experiment. Hence, in the Luquillo Experimental Forest (...

The forest architecture hypothesis for diversity maintenance C an tree species coexist by differing in size? T. Kohyamai recently put forward a convincing case that they can. While there is no shortage of plausible hypotheses for coexistence of competing species, few have received satisfactory tests. The 'forest architecture' hypothesis of Kohyama, however, is refreshing in that it has received...

Weusedtree-rings toreconstruct long-termpatternsof suppression, releaseandgrowthamongfivesympatric canopy tree species representing the full range of shade tolerance in a seasonal tropical forest in western Thailand. We expected that the frequency and duration of suppression and release events would be positively correlated with shade tolerance. All five species showed evidence of major andmode...