Entity

Time filter

Source Type


Boyd I.L.,University of St. Andrews | Freer-Smith P.H.,Japan Forestry and Forest Products Research Institute | Gilligan C.A.,University of Cambridge | Godfray H.C.J.,University of Oxford
Science | Year: 2013

Trees and forests provide a wide variety of ecosystem services in addition to timber, food, and other provisioning services. New approaches to pest and disease management are needed that take into account these multiple services and the different stakeholders they benefit, as well as the likelihood of greater threats in the future resulting from globalization and climate change. These considerations will affect priorities for both basic and applied research and how trade and phytosanitary regulations are formulated. Source


Kerr G.,Japan Forestry and Forest Products Research Institute
Forestry | Year: 2014

In 1898, François de Liocourt published a manuscript 'The management of silver fir forests', which is now considered a seminal paper on the subject of uneven-aged silviculture. The objective of this paper is to review de Liocourt's manuscript and examine its main findings and how they have subsequently been interpreted. De Liocourt's study examined data from seven stands dominated by European silver fir (Abies alba Mill.) close to Gérardmer in northeast France managed using the selection system. He observed that the diameter frequency distributions from the stands all had a characteristic shape and were very similar. He also found that it was possible to derive a frequency distribution that closely resembled those found in the forests using the mathematics of number sequences. These findings were considered by de Liocourt to suggest more precise methods of managing these forests. Subsequently, the paper has been interpreted in a number of different ways, not all of which are accurate. These discrepancies are examined but all authorities who have referenced de Liocourt's paper should be congratulated for their desire to acknowledge the importance of this influential study. © 2013 © Crown copyright 2013. Source


Hydraulic limitations associated with increasing tree height result in reduced foliar stomatal conductance (g s) and light-saturated photosynthesis (A max). However, it is unclear whether the decline in A max is attributable to height-related modifications in foliar nitrogen concentration (N), to mesophyll conductance (gm) or to biochemical capacity for photosynthesis (maximum rate of carboxylation, V cmax). Simultaneous measurements of gas exchange and chlorophyll fluorescence were made to determine g mand V cmax in four height classes of Pinus densiflora Sieb. & Zucc. trees. A s the average height of growing trees increased from 3.1 to 13.7 m, g mdecreased from 0.250 to 0.107 mol m -2 s -1, and the CO 2 concentration from the intercellular space (C i) to the site of carboxylation (C c) decreased by an average of 74mol mol -1. Furthermore, V cmax estimated from C c increased from 68.4 to 112.0mol m -2 s -1 with the increase in height, but did not change when it was calculated based on C i. In contrast, A max decreased from 14.17 to 10.73mol m -2 s -1. Leaf dry mass per unit area (LMA) increased significantly with tree height as well as N on both a dry mass and an area basis. A ll of these parameters were significantly correlated with tree height. In addition, g mwas closely correlated with LMA and g s, indicating that increased diffusive resistance for CO 2 may be the inevitable consequence of morphological adaptation. Foliar N per unit area was positively correlated with V cmax based on C c but negatively with A max, suggesting that enhancement of photosynthetic capacity is achieved by allocating more N to foliage in order to minimize the declines in A max. Increases in the N cost associated with carbon gain because of the limited water available to taller trees lead to a trade-off between water use efficiency and photosynthetic nitrogen use efficiency. In conclusion, the height-related decrease in photosynthetic performance appears to result mainly from diffusive resistances rather than biochemical limitations. © 2011 The Author. Published by Oxford University Press. A ll rights reserved. Source


Ikeda H.,Japan Forestry and Forest Products Research Institute
Nature communications | Year: 2012

The evolution of flight is a key innovation that may enable the extreme diversification of insects. Nonetheless, many species-rich, winged insect groups contain flightless lineages. The loss of flight may promote allopatric differentiation due to limited dispersal power and may result in a high speciation rate in the flightless lineage. Here we show that loss of flight accelerates allopatric speciation using carrion beetles (Coleoptera: Silphidae). We demonstrate that flightless species retain higher genetic differentiation among populations and comprise a higher number of genetically distinct lineages than flight-capable species, and that the speciation rate with the flightless state is twice that with the flight-capable state. Moreover, a meta-analysis of 51 beetle species from 15 families reveals higher genetic differentiation among populations in flightless compared with flight-capable species. In beetles, which represent almost one-fourth of all described species, repeated evolution of flightlessness may have contributed to their steady diversification since the Mesozoic era. Source


Hanane S.,Japan Forestry and Forest Products Research Institute
Integrative Zoology | Year: 2014

The woodpigeon (Columba palumbus) is a common and widespread bird in Morocco (North Africa). I examined, over 2 years (2010 and 2011), the breeding density and nest placement of this game species in relation to nest site habitat and degree of human disturbance. The study area was in the Middle Atlas Tighboula mountain forest, Morocco, in a disturbed and an undisturbed site. Using data collected in the 2 study sites, I aimed to identify the factors influencing the placement of nests within holm oak trees (Quercus rotundifolia) and their densities. I found that habitat structures, influenced by grazing disturbance, have affected nesting density and the location of nests of this species. Woodpigeons place their nests in a higher position (3.42 ± 0.19 m) when disturbance intensity is high and lower (1.68 ± 0.1 m) when disturbance intensity is low, and show higher nesting density in less disturbed zone (3.1 ± 0.4 nests/ha) than in highly disturbed zones (1.4 ± 0.2 nests/ha). Grazing disturbance could pose a threat to population persistence at a broader scale and could potentially reduce the abundance of this species by altering the composition and the structure of the forest nesting habitat. Further multi-scale studies are needed to assess the effects of different levels of grazing disturbance on woodpigeon nest density and placement, and to enhance our knowledge of the breeding behavior of this game species under variable environments. © 2013 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd. Source

Discover hidden collaborations