Mature forests hold maximum live biomass stocks

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.

Download Full-text

Sampling Intensity for Estimating Fuel Moisture Content in Lodgepole Pine and White Spruce Trees

International Journal of Wildland Fire ◽

10.1071/wf9920001 ◽

1992 ◽

Vol 2 (1) ◽

pp. 1 ◽

Cited By ~ 2

Author(s):

SJ Titus ◽

PM Woodard ◽

AF Johnson

Keyword(s):

Moisture Content ◽

Coefficient Of Variation ◽

Lodgepole Pine ◽

White Spruce ◽

Size Class ◽

Fuel Moisture ◽

Probability Level ◽

Content Variation ◽

Live Biomass ◽

Fuel Moisture Content

The moisture content of live and dead foliage and roundwood on 30 lodgepole pine and 27 white spruce trees was determinedduring the summer of 1987. Sample trees were selectedrandomly throughout Alberta, Canada, without regard for weather. Five sub-samples were taken for each of the five roundwood diameter size classes (< 0.5cm,0.5 - 1 cm, 1.0- .0cm,3.0- 5.0cm, 5.0-7.0cm and 7.0-10.0 cm). Moisture content of live biomass was quite similar between species for the same fuel size class, regardless of when sampling occurred. Moisture content variation within trees was about half of the variation between trees for the same fuel size class. The coefficient of variation in moisture was much less for live material (generally < 0.3) than for dead biomass (always > 0.6). Average fuel moisture content for populations of lodgepole pine and white spruce trees may be estimated to within + 10% at the 68% probability level by sampling less than 20 trees and with only 3 fuel sub-samples per tree.

Download Full-text

Nutrients cause grassland biomass to outpace herbivory

Nature Communications ◽

10.1038/s41467-020-19870-y ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

E. T. Borer ◽

W. S. Harpole ◽

P. B. Adler ◽

C. A. Arnillas ◽

M. N. Bugalho ◽

...

Keyword(s):

Human Activities ◽

Food Resource ◽

Grazing Intensity ◽

Fire Risk ◽

Nutrient Supply ◽

Nutrient Inputs ◽

High Vertebrate ◽

Herbivore Exclusion ◽

Live Biomass ◽

Consumer Control

AbstractHuman activities are transforming grassland biomass via changing climate, elemental nutrients, and herbivory. Theory predicts that food-limited herbivores will consume any additional biomass stimulated by nutrient inputs (‘consumer-controlled’). Alternatively, nutrient supply is predicted to increase biomass where herbivores alter community composition or are limited by factors other than food (‘resource-controlled’). Using an experiment replicated in 58 grasslands spanning six continents, we show that nutrient addition and vertebrate herbivore exclusion each caused sustained increases in aboveground live biomass over a decade, but consumer control was weak. However, at sites with high vertebrate grazing intensity or domestic livestock, herbivores consumed the additional fertilization-induced biomass, supporting the consumer-controlled prediction. Herbivores most effectively reduced the additional live biomass at sites with low precipitation or high ambient soil nitrogen. Overall, these experimental results suggest that grassland biomass will outstrip wild herbivore control as human activities increase elemental nutrient supply, with widespread consequences for grazing and fire risk.

Download Full-text

MAJOR FIELD TEST EVALUATES A SHORELINE CLEANER TO SAVE OILED MARSH GRASS

International Oil Spill Conference Proceedings ◽

10.7901/2169-3358-1997-1-397 ◽

1997 ◽

Vol 1997 (1) ◽

pp. 397-402 ◽

Cited By ~ 2

Author(s):

S. R. Pezeshki ◽

R. D. DeLaune ◽

A. Jugsujinda ◽

G. P. Canevari ◽

R. R. Lessard

Keyword(s):

Spartina Alterniflora ◽

Field Test ◽

Field Tests ◽

Field Studies ◽

Test Site ◽

Field Conditions ◽

Marsh Vegetation ◽

Beneficial Effects ◽

Live Biomass ◽

South Louisiana

ABSTRACT Extensive greenhouse studies using intact cores of marsh vegetation including Spartina alterniflora demonstrated the potential of a shoreline cleaner (Corexit 9580) to remove oil from plant canopy. Because of these positive results, a permit to conduct a full-scale field test was obtained by Louisiana State from regulatory agencies in June 1995. Field tests were conducted in a Louisiana marsh at a wildlife refuge in August 1995. The test site contained replicated 8 ft X 8 ft test plots that included the following treatments: oiled with South Louisiana crude oil, oiled and chemically cleaned after 2 days using Corexit 9580, and control. Significant initial reductions in plant stomatal conductance, transpiration, and CO2 fixation rates in response to the “oil” and “oil + Corexit 9580” treatments were noted, which were followed by substantial recovery in the “oil + Corexit 9580” treatment. Use of the cleaner improved the survival and regeneration capability of treated plots because of the low initial mortality rates and the rapid restoration of plant gas exchange activities. Plots treated with “oil + Corexit 9580” had a significantly greater number of live shoots throughout the measurement period in 1995. Biomass harvests conducted at the end of the 1995 growing season revealed that live biomass per unit area of marsh was significantly reduced under all treatments. The second harvest in 1996 indicated that live biomass had recovered to levels close to those of control plots. Our field studies demonstrated that oil can be removed using Corexit 9580 in the field without any detectable adverse effects on plants, In addition, the beneficial effects of Corexit 9580 in rapidly restoring plant transpiration pathways under field conditions was evident. However, plants under all treatments recovered, showing that Spartina alterniflora, given adequate time, can recover from oiling with South Louisiana crude. Additional studies using more stressful oil types such as Bunker C are needed to examine the effectiveness of Corexit 9580 in cleaning plant canopies under field conditions.

Download Full-text

Variation in aboveground tree live biomass in a central Amazonian Forest: Effects of soil and topography

Forest Ecology and Management ◽

10.1016/j.foreco.2006.06.024 ◽

2006 ◽

Vol 234 (1-3) ◽

pp. 85-96 ◽

Cited By ~ 205

Author(s):

Carolina V. de Castilho ◽

William E. Magnusson ◽

R. Nazaré O. de Araújo ◽

Regina C.C. Luizão ◽

Flávio J. Luizão ◽

...

Keyword(s):

Amazonian Forest ◽

Live Biomass

Download Full-text

Mapping growing stock volume and forest live biomass: a case study of the Polissya region of Ukraine

Environmental Research Letters ◽

10.1088/1748-9326/aa8352 ◽

2017 ◽

Vol 12 (10) ◽

pp. 105001 ◽

Cited By ~ 10

Author(s):

Andrii Bilous ◽

Viktor Myroniuk ◽

Dmytrii Holiaka ◽

Svitlana Bilous ◽

Linda See ◽

...

Keyword(s):

Growing Stock ◽

Live Biomass ◽

Stock Volume

Download Full-text

Nest spacing and architecture, and swarming of males of Dinoponera quadriceps (Hymenoptera, Formicidae) in a remnant of the Atlantic Forest in Northeast Brazil

Brazilian Journal of Biology ◽

10.1590/s1519-69842004000200022 ◽

2004 ◽

Vol 64 (2) ◽

pp. 357-362 ◽

Cited By ~ 12

Author(s):

A. Vasconcellos ◽

G. G. Santana ◽

A. K. Souza

Keyword(s):

Atlantic Forest ◽

Climatic Factors ◽

Light Trap ◽

Spatial Arrangement ◽

Territory Size ◽

Nest Density ◽

Northeast Brazil ◽

Live Biomass ◽

Ant Nest ◽

Almost All

Dinoponera quadriceps is a queenless neotropical ponerinae ant. Nest spacing and abundance were investigated in a remnant of the Atlantic forest in Northeast Brazil. Males were captured with a light trap between August 1994 and July 1996. Nest density varied from 15 to 40 ha-1. An overdispersion of nests suggests that the intraspecific competition may be an important factor regulating their spatial arrangement. Territory size was correlated with worker population size of the colonies. The nests had up to 16 chambers, with variations in their architecture closely related to habitat diversification. Populations varied from 12 to 97 adult workers per nest, with a mean density of 1,618 workers ha-1 and a live biomass of 461 g ha-1 (n = 13 nests). Males swarm continually throughout almost all months of the year, suggesting that production and swarming are more influenced by mechanisms that regulate the sexual activity of workers than by climatic factors.

Download Full-text

Recent and future productivity of Russian forests under climate change

10.5194/egusphere-egu2020-10316 ◽

2020 ◽

Author(s):

Anatoly Shvidenko ◽

Dmitry Schepaschenko ◽

Sergey Bartalev ◽

Andrey Krasovskii ◽

Anton Platov

Keyword(s):

Remote Sensing ◽

Forest Inventory ◽

Carbon Budget ◽

Forest Cover ◽

Net Primary Production ◽

Co2 Concentration ◽

Growing Stock ◽

Distributed Modelling ◽

Live Biomass ◽

Russian Forests

<p>Knowledge of dynamics of forest productivity, expressed in terms of Growing Stock Volume (GSV), Net Primary Production (NPP), such derivatives like current increments (net and gross growth), is crucial for understanding the impacts of forest ecosystems on the major global biogeochemical cycles and eventually &#8211; on the Earth climate system. This knowledge is not satisfactory in Russia currently (the country&#8217;s forests cover >20% of the global forest area) because 1) data of official forest inventory are obsolete and substantially biased due to the fact that about 50% of Russian forests were inventoried more than 30 years ago; 2) of the above indicators, Russian forest inventory directly defines only GSV, but by the methods, which have substantial systematic errors of unknown size; 3) remote sensing methods themselves still cannot reliably provide some necessary details, like species composition, age and age structure of stands, below ground live biomass etc. In this presentation, we attempted to provide a systematic reanalysis of the estimates of the above indicators. To this end, a special system was developed to update the data of forest inventory for periods after the latest inventory by forest enterprises (about 1700) based on all available ground-based information and a multi-sensor concept of remote sensing. Hybrid forest cover was presented as an aggregation of 12 satellite products at spatial resolution of 150m. The updating of the main biometric indicators of Russian forests was based on the models of the growth and bioproductivity of modal stands. The results of the actualization have showed substantial overestimation of areas by official inventory and underestimation (up to 20%) of GSV. Comparison of obtained results with an independent assessment of the dynamics of areas and GSV, which was made by the Space Research Institute of the Russian Academy of Sciences for the period 2000-2017, showed a high level of compatibility. Using the results of actualization, live biomass was assessed based on a new system of conversion coefficients (Schepaschenko et al. 2018), NPP - on a method described in Shvidenko et al. (2007); and current increments &#8211; using a regionally distributed modelling system on increment dynamics of modal stands. Climate were analyzed for 3 periods: &#8220;historical&#8221; (1948-1975), &#8220;current&#8221;(1975-2017) and &#8220;future&#8221; (using all 4 scenarios RCP (2020-2100)). NPP and increments were estimated for the two last periods using a model, which takes into account selected climatic indicators and fertilization effect of enhanced CO2 concentration. It is shown that use of the obtained results presents substantial possibility for improvement of estimates of the carbon budget of Russian forests, particularly those received by inventory methods, and eliminate the existing discrepancies in estimates of the carbon budget of Russian forests reported in different publications. Projections for future suppose that significant part of Russian forests under &#8220;critical&#8221; scenarios (RCP6.0 and RCP 8.5) have a high probability to reach the tipping point by end of this century.</p>

Download Full-text

Integrating liana abundance and forest stature into an estimate of total aboveground biomass for an eastern Amazonian forest

Journal of Tropical Ecology ◽

10.1017/s0266467400001437 ◽

2000 ◽

Vol 16 (3) ◽

pp. 327-335 ◽

Cited By ~ 133

Author(s):

Jeffrey John Gerwing ◽

Damião Lopes Farias

Keyword(s):

Aboveground Biomass ◽

Amazon Basin ◽

Forest Disturbance ◽

Weighted Average ◽

Canopy Height ◽

Total Biomass ◽

Biomass Equation ◽

Area Index ◽

Amazonian Forest ◽

Live Biomass

This study provides an estimate of aboveground live biomass for an intact eastern Amazonian forest. An allometric regression biomass equation was developed to estimate the aboveground biomass of live lianas. This equation, together with a previously published equation for trees, was then used to estimate the contributions of lianas and trees to the total biomass of forest patches in four stature classes: gap (openings in the canopy of at least 25 m2 with the dominant vegetation < 3 m high), low (3–15 m canopy height), medium (15–25 m canopy height), and high (> 25 m canopy height). Total stand-level biomass was estimated as the weighted average of the stature classes. In 130 ha of surveyed forest, forest stature classes were found in the following proportions: gap phase 8%; low stature 31%; medium stature 44%; and high stature 17%. Total aboveground biomass was found to be three times higher in high stature forest than in low. Liana biomass, however, showed the opposite result, being three times higher in low stature forest. Stand-level aboveground live biomass was estimated at 314 t ha−1 of which 43 t ha−1 (14%) was lianas. Liana leaf area index (LAI) ranged from 1.3 m m−2 in high stature forest to 5.3 m m−2 in low stature. Abundant lianas are generally interpreted as a sign of past forest disturbance. As forests throughout the Amazon basin are increasingly disturbed through human activities, it is likely that their biomass will be underestimated if the contribution of lianas is ignored.

Download Full-text