Optimum foliar nitrogen concentration in pine and its change with stand age

1981 ◽  
Vol 11 (3) ◽  
pp. 563-572 ◽  
Author(s):  
Hugh G. Miller ◽  
John D. Miller ◽  
Jean M. Cooper

Levels of nitrogen in foliage associated with optimum growth of pine were determined in two hydroponic experiments in the glasshouse and two forest fertilizer experiments each designed to cover the full response range for Pinusnigra var. maritima (Ait.) Melv. During the years prior to canopy closure optimum nitrogen concentrations declined with the logarithm of tree weight, falling from 3.3% in very young seedlings to 1.5% in forest trees of 2.0–2.5 m in height. After canopy closure the level increased to about 2.0%. At all stages the concentrations associated with maximum height growth were less than those for maximum volume, weight, or diameter increment. The relationships in the forest experiments, which are on sand dunes in the north of Scotland, could be improved by including factors of rainfall during the previous August and September and of temperature in June of the same year, but this did not alter the optima. It is concluded that for diagnostic purposes critical foliar nitrogen levels must be qualified by the age or developmental stage of the trees.

1995 ◽  
Vol 25 (3) ◽  
pp. 516-526 ◽  
Author(s):  
R.P. Brockley

The effects of spring and fall applications of urea and ammonium nitrate fertilizer on the nutrition and growth of lodgepole pine (Pinusconforta Dougl. var. latifolia Engelm.) were evaluated at three locations in the interior of British Columbia over a 6-year period. Ammonium nitrate was generally more effective at increasing 1st-year foliar nitrogen concentration than was urea, irrespective of season of application. Spring-applied ammonium nitrate was especially effective in increasing foliar nitrogen levels. Despite the apparent superiority of ammonium nitrate over urea in improving foliar nitrogen status, the basal area increment of fertilized trees in the three trials was not affected by nitrogen source. The effect of season of application on basal area increment was not consistent across all sites or between measurement periods. Spring-applied ammonium nitrate produced the smallest 0- to 3-year basal area and height increments in two of the trials. The negative effects of fertilization on foliar sulphur concentration may partially explain the poor basal area and height response following fertilization at one site and the relatively small response to spring-applied ammonium nitrate at another site. Because spring-applied ammonium nitrate is more effective at increasing foliar nitrogen concentration, it is most likely to create a nitrogen:sulphur imbalance, at least over the short term. Further studies are warranted to test the hypothesis that ammonium nitrate is better than urea at stimulating tree growth when accompanied by sulphur additions.


1992 ◽  
Vol 22 (8) ◽  
pp. 1089-1093 ◽  
Author(s):  
R. Trowbridge ◽  
F.B. Holl

An overdense lodgepole pine (Pinuscontorta Dougl. ex Loud.) stand was knocked down and the site was prepared by broadcast burn, windrow burn, or mechanical forest floor removal. Inoculated alsike clover (Trifoliumhybridum L.) was seeded at 0, 10, 20, and 30 kg/ha for the three different site preparation treatments to determine the effects of (i) site preparation on infection and effectiveness of the clover–Rhizobium symbiosis and clover percent cover and (ii) the clover–Rhizobium N2-fixing symbiosis on survival, early growth, and foliar nitrogen concentration of lodgepole pine seedlings. The N2-fixing symbiosis established well in all treatments. Clover percent cover increased with increasing rate of seeding, although by relatively few percent in the clover seeded plots. Broadcast burning, windrow burning, and mechanical forest floor removal did not affect the establishment of the N2-fixing symbiosis or clover percent cover. Lodgepole pine survival was not affected by the seeding treatments in any year, nor were height measurements during the first three growing seasons. Seedling height was slightly less in clover-seeded plots compared with controls in the fourth growing season. Lodgepole pine seedlings on clover-seeded plots had decreased diameter growth compared with controls during the first three growing seasons, but incremental diameter growth no longer showed this effect by the fourth growing season. Needle mass (g/100 needles) was less in clover-seeded plots at the end of the second growing season, but this effect was reversed by the fourth growing season, when both needle mass and foliar nitrogen concentration in lodgepole pine foliage were greater in clover-seeded plots.


2010 ◽  
Vol 34 (4) ◽  
pp. 515-540 ◽  
Author(s):  
S.G. Tesfamichael ◽  
J.A.N. van Aardt ◽  
F. Ahmed

This study explores the utility of small-footprint, discrete return lidar data in deriving important forest structural attributes with the primary objective of estimating plot-level mean tree height, dominant height, and volume of Eucalyptus grandis plantations. The secondary objectives of the study were related to investigating the effect of lidar point densities (1 point/m2, 3 points/m2, and 5 points/m2) on height and volume estimates. Tree tops were located by applying local maxima (LM) filtering to canopy height surfaces created at each density level, followed by buffering using circular polygons. Maximum and mean height values of the original lidar points falling within each tree polygon were used to generate lidar mean and dominant heights. Lidar mean value was superior to the maximum lidar value approach in estimating mean plot height (R2∼0.95; RMSE∼7%), while the maximum height approach resulted in superior estimates for dominant plot height (R2 ∼0.95; RMSE∼5%). These observations were similar across all lidar point density levels. Plot-level volume was calculated using approaches based on lidar-derived height variables and stems per hectare, as well as stand age. The level of association between estimated and observed volume was relatively high (R2=0.82—0.94) with non-significant differences among estimates at high lidar point densities and field observation. Nearly all estimates, however, exhibited negative biases and RMSE ranging in the order of 20—43%. Overall, the results of the study demonstrate the potential of lidar-based approaches for forest structural assessment in commercial plantations, even though further research is required on improving stems per hectare (SPHA) estimation.


2017 ◽  
pp. 31-54
Author(s):  
Martin Bobinac ◽  
Sinisa Andrasev ◽  
Andrijana Bauer-Zivkovic ◽  
Nikola Susic

The paper studies the effects of two heavy selection thinnings on the increment of Norway spruce trees exposed to ice and snow breaks in eastern Serbia. In a thinning that was carried out at 32 years of age, 556 candidates per hectare were selected for tending, and at the age of 40, of the initial candidates, 311 trees per hectare (55.9%) were selected as future trees. In all trees at 41-50 age period, diameter increment was higher by 31%, basal area increment by 64% and volume increment by 67% compared to 32-40 age period. The collective of indifferent trees is significantly falling behind compared to future trees in terms of increment values in both observed periods. However, the value of diameter, basal area and volume increments, of the collective of "comparable" indifferent trees are lower in comparison to the values of increments of future trees by 10-15% in the 32-40 age period, and by 15-21% in the 41-50 age period and there are no significant differences. The results show that heavy selective thinnings, initially directed at a larger number of candidates for tending at stand age that does not differ much from the period of carrying out first "commercial" thinnings, improve the growth potential of future and indifferent trees, where it is rational to do the tree replacement for the final crop in "susceptible" growth stage to snow and ice breaks.


1985 ◽  
Vol 117 (1) ◽  
pp. 23-32 ◽  
Author(s):  
J. Wayne Brewer ◽  
John L. Capinera ◽  
Robert E. Deshon ◽  
Mary L. Walmsley

AbstractThe influence of nitrogen levels in foliage of white-fir, Abies concolor, and Douglas-fir, Pseudotsuga menziesii, seedlings on various biological characteristics of the western spruce budworm, Choristoneura occidentalis Freeman, was studied. Seedlings were grown under greenhouse conditions and provided with nutrient solutions to maintain five foliar nitrogen levels ranging from 1.29 to 4.42% dry weight for white fir and 1.43 to 3.94% for Douglas fir. Larvae confined to treated seedlings were monitored through the next generation. Larval mortality was higher, and development time longer, at both upper and lower extremes of foliar nitrogen than at mid-level. Mean pupal weight was significantly greater for larvae reared on white fir with the mid-range foliar-nitrogen level. Mean number, and weight, of eggs laid were highest when larvae fed on foliage from the mid-range nitrogen level. Total number of larvae produced was lowest at the high and low extremes of foliar nitrogen levels.


Author(s):  
Eduard Koster

The literature on aeolian processes and on aeolian morphological and sedimentological features has shown a dramatic increase during the last decade. A variety of textbooks, extensive reviews, and special issues of journal volumes devoted to aeolian research have been published (Nordstrom et al. 1990; Pye and Tsoar 1990; Kozarski 1991; Pye 1993; Pye and Lancaster 1993; Cooke et al. 1993; Lancaster 1995; Tchakerian 1995; Livingstone and Warren 1996; Goudie et al. 1999). However, not surprisingly the majority of these studies discuss aeolian processes and phenomena in the extensive warm arid regions of the world. The results of aeolian research in the less extensive, but still impressive, cold arid environments of the world are only available in a diversity of articles. At best they are only briefly mentioned in textbooks on aeolian geomorphology (Koster 1988, 1995; McKenna-Neuman 1993). Likewise, the literature with respect to wind-driven deposits in western Europe is scattered and not easily accessible. The aeolian geological record for Europe, as reflected in the ‘European sand belt’ in the north-western and central European Lowlands, which extends from Britain to the Polish–Russian border, is known in great detail (Koster 1988; van Geel et al. 1989; Böse 1991). Zeeberg (1998) showed that extensive aeolian deposits progress with two separate arms into the Baltic Region, and into Belorussia and northernmost Ukraine. Recently, Mangerud et al. (1999) concluded that the sand belt extends even to the Pechora lowlands close to the north-western border of the Ural mountain range in Russia. Sand dunes and cover sands are widespread and well developed in this easternmost extension of the European sand belt. The northerly edges of this sand belt more or less coincide with the maximal position of the Late Weichselian (Devensian, Vistulian) ice sheet, while the southern edges grade into coverloams or sandy loess and loess (Mücher 1986; Siebertz 1988; Antoine et al. 1999). However, along these southern edges the dune fields and sand sheets regionally are derived from different sources, such as the sands of the Keuper Formation or the floodplains of the Rhine and Main rivers.


Author(s):  
Robert Van de Noort

The North Sea is not renowned for its islands, and much of the modern land–sea interface is sharp, especially along the coasts of Jutland, North and South Holland and much of England. Nevertheless, the North Sea does contain a surprisingly large number of islands and archipelagos, which can be presented with reference to a clear north–south divide. In the northern half of the North Sea, most islands are of hard rock with shallow soils, and their islandness is the result of ongoing glacio-isostatic uplift of previously drowned lands and sea-level rise. With the exception of the Shetland and Orkney archipelagos, few of these islands are found at a great distance from the mainland, and the majority of the countless islands, islets, and rock outcrops off the North Sea coasts of Norway, Sweden, Scotland, and north-east England can be found within a few miles of the mainland. In the southern half of the North Sea, the islands are mainly made up of sand and clay and, in their history if not today, were frequently sandbanks formed by the sea utilizing both marine and riverine sediments. Most of the islands of the Wadden Sea in Denmark, Germany, and Holland are sandbanks elevated by aeolian-formed sand dunes. Further south, the core of the large islands of Zeeland is principally formed of riverine sands and marine clays intercalated with peat, reflecting coastal wetland conditions at various times in the Post-glacial and Holocene (Vos and Van Heeringen 1997). As with Zeeland, the islands on the English side of the North Sea, such as Mersey Island in the Blackwater estuary and Foulness Island in Essex, have now been incorporated into the mainland. Only a few islands cannot be so simply classified:Helgoland in the German Bight, a Sherwood Sandstone stack of Triassic date, is the best known example. Island archaeology, as we have seen (chapter 2), has for many decades approached islands as environments that were relatively isolated from the wider world.


1875 ◽  
Vol 2 (12) ◽  
pp. 587-588
Author(s):  
T. Mellard Reade

I am not aware that any geological notice has been taken of the effect of the wind on a flat sandy shore, further than the simple removal of the sand therefrom, and its collection on the sea-margin in the shape of sand dunes.At the present moment a walk on the shore at Blundellsands has vividly impressed me with the efficacy of this agent—wind—as a denuder.Though I have frequently observed the phenomenon I am about to describe, after continued gales from the North-West, I never saw it displayed in so uniform a manner as now.


2017 ◽  
Vol 63 (No. 11) ◽  
pp. 511-518 ◽  
Author(s):  
Mohammadi Zohreh ◽  
Limaei Soleiman Mohammadi ◽  
Lohmander Peter ◽  
Olsson Leif

The aim of the study is to estimate the aboveground carbon sequestration and to determine the economic value of forests in carbon sequestration as a way of mitigating climate change. This research was conducted at Asalem forests in the north of Iran. In order to estimate the amount of annual carbon sequestration, the annual volume growth of stand was determined using the diameter increment data and tariff. The amount of carbon sequestration was estimated based on wood density and using the allometric equation. The carbon model was obtained for each species. The value of sequestrated carbon in stumpage and the net present value of carbon sequestration were determined in order to estimate the economic value of carbon sequestration. Results indicated that the annual volume growth per hectare and the carbon stored are 6.023 m<sup>3</sup>·yr<sup>–1</sup> and 2.307 t·ha<sup>–1</sup>, respectively. Finally, the carbon sequestration value of stumpage and the net present value of carbon sequestration are 11,023.753 and 790.361 (10,000 IRR·t<sup>–1</sup>·ha<sup>–1</sup>), respectively. Our results are very useful in estimating the total economic value of Asalem forests and other Iranian Caspian forests in the future.


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