Links between biomass and tree demography in a northern hardwood forest: a decade of stability and change in Hubbard Brook Valley, New Hampshire

2011 ◽  
Vol 41 (7) ◽  
pp. 1369-1379 ◽  
Author(s):  
Natalie S. van Doorn ◽  
John J. Battles ◽  
Timothy J. Fahey ◽  
Thomas G. Siccama ◽  
Paul A. Schwarz

We resurveyed a network of sampling plots (n = 371) 10 years after its establishment in Hubbard Brook Experimental Forest (New Hampshire, USA) to quantify recent trends in tree biomass and demography. We found no significant change in live-tree biomass during the decade. Total biomass was 246 Mg·ha–1 (95%CI = 235–258) in 1995–1996 and 245 Mg·ha–1 (95%CI = 234–256) in 2005–2006. Annual mortality during the period for trees ≥ 10 cm diameter at breast height (1.37 m) averaged 9.7 trees·ha–1·year–1 (95% CI of annual mortality rate = 1.36%–1.84%·year–1). Tree recruitment into the census pool was 8.4 trees⋅ha–1·year–1 (95% CI = 5.8–10.6). Although overall forest biomass remained constant, there were marked shifts in the relative dominance of the canopy species. For example, the live biomass of Betula alleghaniensis Britton declined by 7%, whereas the live biomass of Picea rubens Sarg. increased by 6% and that of Acer saccharum Marshall increased by 4%. There was no instance of recruitment significantly exceeding mortality for the major species. Relative growth rates ranged from 1.03%·year–1 for Betula papyrifera Marshall to 1.99%·year–1 for Abies balsamea (L.) Mill. Our results confirmed earlier reports that the forest at Hubbard Brook is no longer aggrading. Current live-tree biomass is lower than expected. Although effects of novel disturbances documented on a regional level have not led to directional changes in tree demography at Hubbard Brook, we suggest that these novel stressors are depressing the biomass potential of the forest.

1998 ◽  
Vol 28 (3) ◽  
pp. 494-498 ◽  
Author(s):  
Jason D Demers ◽  
Thomas D Lee ◽  
James P Barrett

The relationships between tree species distribution and substrate characteristics were examined at the upper elevational limit of sugar maple (Acer saccharum Marsh.) in the White Mountain National Forest, New Hampshire. Four tree species were studied: sugar maple, balsam fir (Abies balsamea (L.) Mill.), red spruce (Picea rubens Sarg.), and yellow birch (Betula alleghaniensis Britton). At 51 individual trees (>=2.5 cm diameter at breast height) of each species, "substrate type" was described based on the parent material, soil horizons, depth and texture of the B and C horizons, nature of surface boulders, and the depth to and type of impermeable layer. Substrate type was significantly (p < 0.001) associated with tree species. Sugar maple was relatively more frequent on deep fine and compact tills, less frequent on washed or shallow till, and absent on shallow, organic, or grus (weathered granite) substrates. Red spruce, balsam fir, and yellow birch were less sensitive to substrate type. Red spruce and yellow birch were most frequent on organic material or grus over rock. Balsam fir most frequently occurred on washed till. As the frequency of substrates favorable to sugar maple declined with elevation, it is possible that the upper elevational range limit of this species is influenced by substrate availability.


2006 ◽  
Vol 21 (2) ◽  
pp. 195-211 ◽  
Author(s):  
Bongghi Hong ◽  
Dennis P. Swaney ◽  
David A. Weinstein

2012 ◽  
Vol 9 (8) ◽  
pp. 3381-3403 ◽  
Author(s):  
T. R. Feldpausch ◽  
J. Lloyd ◽  
S. L. Lewis ◽  
R. J. W. Brienen ◽  
M. Gloor ◽  
...  

Abstract. Aboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer the following questions: 1. What is the best H-model form and geographic unit to include in biomass models to minimise site-level uncertainty in estimates of destructive biomass? 2. To what extent does including H estimates derived in (1) reduce uncertainty in biomass estimates across all 327 plots? 3. What effect does accounting for H have on plot- and continental-scale forest biomass estimates? The mean relative error in biomass estimates of destructively harvested trees when including H (mean 0.06), was half that when excluding H (mean 0.13). Power- and Weibull-H models provided the greatest reduction in uncertainty, with regional Weibull-H models preferred because they reduce uncertainty in smaller-diameter classes (≤40 cm D) that store about one-third of biomass per hectare in most forests. Propagating the relationships from destructively harvested tree biomass to each of the 327 plots from across the tropics shows that including H reduces errors from 41.8 Mg ha−1 (range 6.6 to 112.4) to 8.0 Mg ha−1 (−2.5 to 23.0). For all plots, aboveground live biomass was −52.2 Mg ha−1 (−82.0 to −20.3 bootstrapped 95% CI), or 13%, lower when including H estimates, with the greatest relative reductions in estimated biomass in forests of the Brazilian Shield, east Africa, and Australia, and relatively little change in the Guiana Shield, central Africa and southeast Asia. Appreciably different stand structure was observed among regions across the tropical continents, with some storing significantly more biomass in small diameter stems, which affects selection of the best height models to reduce uncertainty and biomass reductions due to H. After accounting for variation in H, total biomass per hectare is greatest in Australia, the Guiana Shield, Asia, central and east Africa, and lowest in east-central Amazonia, W. Africa, W. Amazonia, and the Brazilian Shield (descending order). Thus, if tropical forests span 1668 million km2 and store 285 Pg C (estimate including H), then applying our regional relationships implies that carbon storage is overestimated by 35 Pg C (31–39 bootstrapped 95% CI) if H is ignored, assuming that the sampled plots are an unbiased statistical representation of all tropical forest in terms of biomass and height factors. Our results show that tree H is an important allometric factor that needs to be included in future forest biomass estimates to reduce error in estimates of tropical carbon stocks and emissions due to deforestation.


Author(s):  
P. F. Cannon

Abstract A description is provided for Isthmiella faullii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Apparently confined to Abies balsamea. DISEASE: Causes a needle blight of Abies balsamea. According to Darker (1932), it 'is the commonest and most destructive of the Hypodermataceae on Abies balsamea in eastern North America'. It is particularly damaging to seedlings and juvenile plants. In northern Ontario, from where the disease was originally identified, infection occurs during the summer, but signs of the disease do not appear until the following spring, when needles become brown and conidiomata develop, conidia being discharged in July, and shortly after this ascomata begin to form, maturing in July of the following year. GEOGRAPHICAL DISTRIBUTION: Reported from Canada: Nova Scotia, Ontario, Quebec and USA: Michigan and New Hampshire. TRANSMISSION: Through air dispersal of ascospores, which directly infect the leaves (Darker, 1932).


1986 ◽  
Vol 20 (9) ◽  
pp. 1825-1828 ◽  
Author(s):  
James A. Fay ◽  
Dan Golomb ◽  
Subramanyam Kumar

2021 ◽  
Vol 19 (1) ◽  
pp. 60-65
Author(s):  
Oktavianus Cahya Anggara ◽  
Laily Agustina Rahmawati

The terminal in Bojonegoro District is Rajekwesi Type A Terminal. It is located close to the CBD that has resulted in a decrease in environmental quality, due to gas emissions released by motor vehicles. The decrease in environmental quality can be overcome with an ecological approach, for example by creating or expanding green open spaces (urban forest). This study aimed to provide information about the capability of urban forest of the terminal to absorb CO2 emissions. This study began with a survey counting the number of motor vehicles at the gateway of the terminal on Sunday, Monday, Wednesday, Friday and Saturday for 24 hours. Then, the measurement of tree biomass was carried out using the nondestructive method. After the data was collected, the amount of CO2 emissions from motor vehicles was calculated by adding up CO2 emissionsin a stationary (idle) position when it was moving. The total CO2 emissions of motor vehicles at Rajekwesi Type A Terminal was 292.058,087 kgCO2/year. The amount of carbon sink (Wtc) of a tree was calculated by multiplying the total biomass (Wt) by the carbon concentration. The amount of Wtc at the urban forest of Rajekwesi Type A Terminal was 4.366,059 kg/year. After the amount of Wtc was found out, the amount of CO2 absorbed by the tree could be found out by multiplying Wtc by the conversion constant of the carbon (C) element to CO2 (3,67). The amount of CO2 absorbed by the trees at the urban forest of Rajekwesi Type A Terminal was 16.023,44 kgCO2/year. If they were compared, the absorption of CO2 was still much smaller than the emission rate. Thus, the function of the urban forest of terminal as an absorber of CO2 emissions was still not optimal.


2016 ◽  
Vol 21 (1) ◽  
pp. 65-70
Author(s):  
Smrita Acharya ◽  
Udhab Raj Khadka

Landslide causes massive loss of lives and properties along with intangible losses in mountainous regions. Yet such intangible losses in ecosystems are rarely considered. The present study assesses the tree biomass lost due to Jure landslide in Sindhupalchowk that destroyed 71 hectare of land. Altogether, 12 plots (250 m2) were sampled through systematic and purposive sampling technique. The total tree biomass was estimated using allometric equation. The study recorded 21 tree species in which Schimawallichiii (Korth.), Lagerstroemia parviflora (Roxb.), Shorea robusta (Gaertn.), Alnus nepalensis (D. Don), Phyllanthus emblica (Linn.) and Celtius australis (Linn.) were dominant. Schima wallichiii had the highest density (320 individual ha-1) and frequency (92%). The total biomass of tree species was 216 ton ha-1 in which Schima wallichiii constituted the highest total tree biomass (82 ton ha-1). In 71 ha landslide area, the landslide caused loss of 15,336 tons of total tree biomass, which equals to 56,283 tons CO2 equivalents. These findings are relevant for assessing post-landslide impacts on the mountain environment. Furthermore, to reduce carbon emissions resulting from forest loss, mitigation of landslide is crucial.Journal of Institute of Science and TechnologyVol. 21, No. 1, 2016,Page: 65-70


1981 ◽  
Vol 45 (9) ◽  
pp. 1421-1437 ◽  
Author(s):  
Noye M. Johnson ◽  
Charles T. Driscoll ◽  
John S. Eaton ◽  
Gene E. Likens ◽  
William H. McDowell

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