Aboveground Biomass Increment Research Articles

Predicting Aboveground Biomass Increment of Tropical Forests from Litter-fall

Predicting Aboveground Biomass Increment (ABI) of forests is important in evaluating primary productivity, and hence aboveground C sequestration rate and C policy implementation. Although there are direct methods such as remote sensing to predict the ABI, it is important to develop ground-based indirect methods, particularly for tropical forests, due to their stratification, complex structure and high diversity, which cannot be imaged properly using the direct methods. Present study developed regression models from a global database of tropical forests to predict the ABI from annual litter-fall. The new models could predict up to 92% and 66% of the variability of the ABI of the disturbed/managed and natural tropical forests, respectively, compared to 69% of the variability predicted by previous models, although they have used a part of the present database which was only available at that time. Field prediction of the new models by using a wet zone forest and a dry zone forest in Sri Lanka showed that the ABIs of the two forests (7-8 Mg ha-1 yr-1) are towards the upper limit (10 Mg ha-1 yr-1) of the tropical forests of the world. It is clear from this study that the new approach may be a better method for predicting the ABI in future research as well as tropical forest inventories. It is recommended however, that the models should be validated before their wider applications.DOI: http://dx.doi.org/10.4038/cjsbs.v42i1.5897 Ceylon Journal of Science (Bio. Sci.) 42 (1): 35-40, 2013

Repelencia al agua en suelos forestales afectados por incendios y en suelos agrícolas bajo distintos manejos y abandono

Soil water repellency determines the water available in the soil system, the runoff generation and the geomorphologic processes. This study examines the soil wettability during the summer of 2008 and 2009 in forest soils with different fire history, and in agricultural soils with different managements. Water repellency was assessed using the Water Drop Penetration Time test (WDPT). Results indicate that water repellency is more frequent and persistent in forest soils than in agricultural ones. In the former, water repellency is reduced a year after a fire and is not recovered during at least 12 years. In agricultural soils, it is found under no till treatment, whereas sites treated with herbicides or tillage were virtually unaffected. Water repellency is exhibited because of the increment of aboveground biomass and organic matter content as the vegetation is recovered following a wildfire or after abandoned crop fields, and after adding reaping or with green manure. In any case, water repellency levels are not either high or continuous enough to produce important runoff and erosion rates in the agricultural soils, although this can occur after forest fires if the soil it is not still protected by the vegetation recovery. Land abandonment trigger the water repellency on soils, and in our case fire reduce it for some years.

Estimating Aboveground Biomass and Average Annual Wood Biomass Increment with Airborne Leaf-on and Leaf-off LiDAR in Great Lakes Forest Types

Estimating Aboveground Biomass and Average Annual Wood Biomass Increment with Airborne Leaf-on and Leaf-off LiDAR in Great Lakes Forest Types

Effects of species richness, identity and environmental variables on growth in planted mangroves in Kenya

Anthropogenic impacts on biodiversity across a wide range of ecosystems are well docu- mented; however the responses of ecosystems to re- duced diversity are still poorly understood. We investi- gated the effects of species richness, species identity and environmental variables on aboveground biomass increment using replanted mangroves at Gazi Bay, Kenya. We planted 32 plots (36 m 2 ) with 8 treat - ments: all possible combinations of the trees Avicennia marina, Bruguiera gymnorrhiza, and Ceriops tagal and an unplanted control. Trees were planted in July and August 2004 and monitored annually until 2009. Growth was slow in the first 2 yr of the study, but by 2007 there was a significant treatment effect on aboveground biomass. A. marina showed strong competitive traits, with the best growth overall and enhanced growth of individual trees when planted in mixed species plots. The highest biomass was recorded in 3-species mixes; partitioning the net effects of species mixing showed a strong species selection effect, but there was also a complementarity effect in some of the three species plots. Biomass was positively correlated with presence of A. marina and negatively correlated with sediment salinity. We conclude that there is variation in the stages of plant development at which species richness effects manifest themselves; in addition the effects of environmental variables have a bearing on the nature and direction of the relationship between species richness and ecosystem function.

Possible Negative Effect of General Flowering on Tree Growth and Aboveground Biomass Increment in a Bornean Tropical Rain Forest

AbstractWe tested the effect of general flowering (GF), community‐wide masting, and drought stress on current‐year tree diameter growth and aboveground biomass increment (ABI). General flowering but not drought had a marginally significant negative effect on tree growth and ABI at the community level. Analyses of dominant species clarified this pattern.

Aboveground net primary productivity in tropical forest regrowth increases following wetter dry-seasons

Aboveground net primary productivity (ANPP) represents an important integrated measure of resource effects on forest ecosystem functions. Rates of ANPP, as well as resource availability controls over ANPP, are poorly understood for tropical forest regrowth following agricultural abandonment, although such regrowth accounts for a large and growing proportion of tropical landscapes. Here, we report on the response of ANPP to inter-annual variability in dry-season precipitation and to four years of dry-season irrigation in a forest regrowth stand in eastern Amazonia. ANPP was most strongly correlated with previous-year annual and dry-season precipitation inputs, suggesting a lag effect of the influence of precipitation on ANPP. The dry-season irrigation experiment provides some confirmation of this lag effect: ANPP response to treatment was significant for 2002 and 2003, following strong previous-year dry seasons, but not during the first treatment year (2001) or 2004, following the weak 2003 dry season. ANPP response to both inter-annual precipitation variability and to dry-season was largely due to a response in aboveground biomass increment rather than litterfall. Drought constraints on aboveground biomass increment suggest that the potential of forest regrowth to sequester atmospheric carbon will decrease with projected reductions in regional rainfall.

Effectiveness of soil N availability indices in predicting site productivity in the oil sands region of Alberta

Background and aims Quantitative relationships between soil N availability indices and tree growth are lacking in the oil sands region of Alberta and this can hinder the development of guidelines for the reclamationof the disturbed landscape after oil sands extraction. The aim of this paper was to establish quantitative relationships between soilN availability indices and tree growth in the oil sands region of Alberta. Methods In situ N mineralization rates, in situ N availabilitymeasuredinthefieldusingPlant RootSimulators (PRS™probes),laboratoryaerobicandanaerobicsoilN mineralization rates, and soil C/N and N content were determined for both the forest floor and the 0–20 cm mineral soil in eight jack pine (Pinus banksiana Lamb.) stands in the oil sands region in northern Alberta. Tree growth rates were determined based on changes in tree ring width in the last 6 years and as mean annual aboveground biomass increment. Results Soil N availability indices across those forest stands varied and for each stand it was several times higher in the forest floor than in the mineral soil. The in situ and laboratory aerobic and anaerobic soil N mineralization rates, soil mineralized N, in situ N availability measured using PRS probes, soil C/N ratio and N content in both the forest floor and mineral soil,

Experimenting the design-based k-NN approach for mapping and estimation under forest management planning

Estimation and mapping of forest attributes are a fundamental support for forest management planning. This study describes a practical experimentation concerning the use of design-based k-Nearest Neighbors (k-NN) approach to estimate and map selected attributes in the framework of inventories at forest management level. The study area was the Chiarino forest within the Gran Sasso and Monti della Laga National Park (central Italy). Aboveground biomass and current annual increment of tree volume were selected as the attributes of interest for the test. Field data were acquired within 28 sample plots selected by stratified random sampling. Satellite data were acquired by a Landsat 5 TM multispectral image. Attributes from field surveys and Landsat image processing were coupled by k-NN to predict the attributes of interest for each pixel of the Landsat image. Achieved results demonstrate the effectiveness of the k-NN approach for statistical estimation, that is compatible with the produced forest attribute raster maps and also proves to be characterized, in the considered study case, by a precision double than that obtained by conventional inventory based on field sample plots only.

Carbon allocation in a Costa Rican dry forest derived from tree ring analysis

The rising discussion on carbon balance of tropical forests often does not consider the sequestration potential of secondary dry forests, which are becoming an increasing importance due to land use change and reforestation. We have developed an easy applicable tool for the estimation of biomass increment of tropical secondary forest stands on the base of tree ring analysis. The existence of annual rings was shown by a combination of anatomical examination and radiocarbon estimations. With tree ring analysis, forest inventories and destructive sampling the above-ground biomass increment of secondary forest stands of age between 9 and 48 years in the dry forest region of Guanacaste, Costa Rica were estimated. The above-ground biomass increment of the tree layer varies between 2.4 and 3.2Mg/hayr in different stands. Lianas contribute with up to 23% additional production. Differences in productivity among the stands along a chronosequence were not significant. The measured carbon allocation potential of 1.7–2.1MgC/hayr lies in the range of reported values from other tropical dry forests and old growth humid forests as well.

Diversity-Carbon Flux Relationships in a Northwest Forest

While aboveground biomass and forest productivity can vary over abiotic gradients (e.g., temperature and moisture gradients), biotic factors such as biodiversity and tree species stand dominance can also strongly influence biomass accumulation. In this study we use a permanent plot network to assess variability in aboveground carbon (C) flux in forest tree annual aboveground biomass increment (ABI), tree aboveground net primary productivity (ANPPtree), and net soil CO2 efflux in relation to diversity of coniferous, deciduous, and a nitrogen (N)-fixing tree species (Alnus rubra). Four major findings arose: (1) overstory species richness and indices of diversity explained between one third and half of all variation in measured aboveground C flux, and diversity indices were the most robust models predicting measured aboveground C flux; (2) trends suggested decreases in annual tree biomass increment C with increasing stand dominance for four of the five most abundant tree species; (3) the presence of an N-fixing tree species (A. rubra) was not related to changes in aboveground C flux, was negatively related to soil CO2 efflux, and showed only a weak negative relationship with aboveground C pools; and (4) stands with higher overstory richness and diversity typically had higher soil CO2 efflux. Interestingly, presence of the N-fixing species was not correlated with soil inorganic N pools, and inorganic N pools were not correlated with any C flux or pool measure. We also did not detect any strong patterns between forest tree diversity and C pools, suggesting potential balancing of increased C flux both into and out of diverse forest stands. These data highlight variability in second-growth forests that may have implications for overstory community drivers of C dynamics.

Carbon stocks in selected dry and wet zone forests of Sri Lanka

Understanding forest C sequestration of the tropical region is of paramount importance to reduce atmospheric CO2. Present study investigated C stocks of two selected wet (Udawattakele – Kandy) and dry zone (Sigiriya sanctuary) forests of Sri Lanka. Litter and soil samples were collected randomly in monthly intervals to cover an annual cycle. Plant biomass C stocks were calculated from standard biomass equations. Soil C was determined by chemical oxidation and loss on ignition (LOI) methods. Above ground biomass increment (AGBI) was predicted by a developed model.The wet zone forest contained higher plant biomass C (249 t C/ha), annual biomass increment (4.85 t C/ha/yr), soil C stock (108 t C/ha) and litter fall C stock (5.73 t C/ha) than those of the dry zone forest of which the corresponding values were 77.0 t C/ha, 4.72 t C/ha, 93.6 t C/ha and 4.72 t C/ha, respectively. Higher amounts of fine root and floor litter C stocks (2.7 t C/ha and 2.36 t C/ha, respectively) were present in the dry zone forest than the wet zone forest (2.4 t C/ha and 2.01 t C/ha, respectively).Total ecosystem C stock (361 t/ha) was higher in the wet zone forest than the dry zone forest (176 t/ha). In the dry zone forest, ca. 53% of the total C stock was in the soil, and ca. 44% was in the plant biomass, and corresponding values of the wet zone forest were 30% and 69%, respectively. Although these proportions were different, higher C stocks in the soil as well as plant biomass were stored in the wet zone forest contributing more towards C sequestration.

Aboveground productivity of an unsuccessful 140-year-old Cryptomeria japonica plantation in northern Kyushu, Japan

We measured the aboveground biomass, biomass increment and litterfall production of a 140-year-old, abandoned Cryptomeria japonica plantation in order to infer the effects of topography on biomass production. The plantation was unsuccessful and the naturally regenerated broad-leaved trees contributed 93.4% (374.2 Mg ha−1) of the total aboveground biomass (400.2 Mg ha−1). Comparing between different slope positions, aboveground biomass decreased downslope corresponding to the decrease in broad-leaved tree biomass. The biomass of C. japonica did not vary with slope position. Biomass increment and litterfall production of the broad-leaved trees also decreased downslope. However, litterfall production per unit biomass and aboveground net primary production per unit biomass increased downslope. Results of a path analysis showed that biomass increment of C. japonica decreased with increasing topographical convexity, whereas biomass and litterfall production of broad-leaved tree increased. Litterfall production of broad-leaved tree decreased with increasing biomass of C. japonica, suggesting that, despite their small biomass, the presence of residual C. japonica may have negative effects on the distribution and productivity of the broad-leaved trees. Our results indicated that total aboveground biomass of the study site was comparable to that of old-growth C. japonica plantations. We inferred that the variation in aboveground biomass of the broad-leaved trees was largely determined by the topography, while their productivity was affected by interactions with planted C. japonica.

Transformation of solar radiation in Norway spruce standsinto produced biomass - the effect of stand density

The present paper is focused on an assessment of the effects of stand density and leaf area development on radiation use efficiency in the mountain cultivated Norway spruce stand. The young even-aged (17-years-old in 1998) plantation of Norway spruce was divided into two experimental plots differing in their stand density in 1995. During the late spring of 2001 next cultivating high-type of thinning of 15% intensity in a reduction of stocking density was performed. The PAR regime of investigated stands was continually measured since 1992. Total aboveground biomass (TBa) and TBa increment (ΔTBa) were obtained on the basis of stand inventory. The dynamic of LAI development showed a tendency to be saturated, i.e. the LAI value close to 11 seems to be maximal for the local conditions of the investigated mountain cultivated Norway spruce stand in the Beskids Mts. Remarkable stimuli (up to 17%) of LAI formation were started in 2002, i.e. as an immediate response to realized thinning. Thus, the positive effect of thinning on LAI increase was confirmed. The data set of absorbed PAR and produced TBa in the period 1998–2003 was processed by the linear regression of Monteith's model, which provided the values of the coefficient of solar energy conversion efficiency into biomass formation (ε). The differences in ε values between the dense and sparse plot after realized thinning amounted to 18%.

Parameter and prediction uncertainty in an optimized terrestrial carbon cycle model: Effects of constraining variables and data record length

[1] Many parameters in terrestrial biogeochemical models are inherently uncertain, leading to uncertainty in predictions of key carbon cycle variables. At observation sites, this uncertainty can be quantified by applying model-data fusion techniques to estimate model parameters using eddy covariance observations and associated biometric data sets as constraints. Uncertainty is reduced as data records become longer and different types of observations are added. We estimate parametric and associated predictive uncertainty at the Morgan Monroe State Forest in Indiana, USA. Parameters in the Local Terrestrial Ecosystem Carbon (LoTEC) are estimated using both synthetic and actual constraints. These model parameters and uncertainties are then used to make predictions of carbon flux for up to 20 years. We find a strong dependence of both parametric and prediction uncertainty on the length of the data record used in the model-data fusion. In this model framework, this dependence is strongly reduced as the data record length increases beyond 5 years. If synthetic initial biomass pool constraints with realistic uncertainties are included in the model-data fusion, prediction uncertainty is reduced by more than 25% when constraining flux records are less than 3 years. If synthetic annual aboveground woody biomass increment constraints are also included, uncertainty is similarly reduced by an additional 25%. When actual observed eddy covariance data are used as constraints, there is still a strong dependence of parameter and prediction uncertainty on data record length, but the results are harder to interpret because of the inability of LoTEC to reproduce observed interannual variations and the confounding effects of model structural error.

Assessing the impacts of climate change and nitrogen deposition on Norway spruce (Picea abies L. Karst) growth in Austria with BIOME-BGC

The aim of this paper is to determine whether a detectable impact of climate change is apparent in Austrian forests. In regions of complex terrain such as most of Austria, climatic trends over the past 50 years show marked geographic variability. As climate is one of the key drivers of forest growth, a comparison of growth characteristics between regions with different trends in temperature and precipitation can give insights into the impact of climatic change on forests. This study uses data from several hundred climate recording stations, interpolated to measurement sites of the Austrian National Forest Inventory (NFI). Austria as a whole shows a warming trend over the past 50 years and little overall change in precipitation. The warming trends, however, vary considerably across certain regions and regional precipitation trends vary widely in both directions, which cancel out on the national scale These differences allow the delineation of 'climatic change zones' with internally consistent climatic trends that differ from other zones. This study applies the species-specific adaptation of the biogeochemical model BIOME-BGC to Norway spruce (Picea abies (L.) Karst) across a range of Austrian climatic change zones, using input data from a number of national databases. The relative influence of extant climate change on forest growth is quantified, and compared with the far greater impact of non-climatic factors. At the national scale, climate change is found to have negligible effect on Norway spruce productivity, due in part to opposing effects at the regional level. The magnitudes of the modeled non-climatic influences on aboveground woody biomass increment increases are consistent with previously reported values of 20-40 kg of added stem carbon sequestration per kilogram of additional nitrogen deposition, while climate responses are of a magnitude difficult to detect in NFI data.

An estimation of Scots pine (Pinus sylvestris L.) ecosystem productivity on reclaimed post-mining sites in Poland (central Europe) using of allometric equations

The work presents determination of the productivity of post-mining ecosystems (PME) derived from the aboveground biomass and annual biomass increment of Scots pine (Pinus sylvestris L.) stands. Single tree biomass assessment data from 42 cut trees were used in developing local allometric equations which may be used as an index during post-mining reforestation projects. The total biomass of pine ecosystems was determined from dendrometric measurements of sample plots with the use of elaborated equations. Forest floor vegetation was determined using the harvest method. Control plots were set up in the vicinity of the mining-sites at a managed forest on natural pine sites (NPS). Results confirm wide ecological amplitude of pine and indicate a high PME productivity on all substrates (2.79–4.34Mgha−1yr−1).

Dominance by the introduced tree Rhamnus cathartica (common buckthorn) may limit aboveground carbon storage in Southern Wisconsin forests

Many ecosystems are now dominated by introduced species, and because dominant species drive ecosystem properties, these changes lead to increased uncertainty in estimates of carbon storage and cycling. We examined aboveground biomass in forests dominated by the introduced tree Rhamnus cathartica (common buckthorn) relative to forests dominated by native species, and measured aboveground biomass increment over a three-year period (2005–2008). Three of the four lowest biomass levels occurred in R. cathartica-dominated forests, and biomass in these forest types was stored primarily in trees 10–20cm DBH. By contrast, forests dominated by native trees (including those with R. cathartica understories) had the six highest biomass levels, and biomass was stored primarily in trees >50cm DBH. On average, forests dominated by R. cathartica stored half as much aboveground biomass (14.6±3.3kg/m2) as forests dominated by native tree species (28.9±8.3kg/m2). R. cathartica-dominated forests also had half the aboveground biomass increment of native-dominated forests (0.28 vs. 0.60kg/m2/year). Although known anecdotally as a fast-growing species, R. cathartica growth rates declined with increasing size. Between 2005 and 2008, R. cathartica individuals <10cm DBH grew faster than native species; however, R. cathartica individuals >10cm DBH grew consistently slower than native species. Overall, our findings indicate that intrinsic size limitations on R. cathartica will lead to lower biomass stocks in forests where it acts as a canopy dominant relative to forests dominated by native tree species.

Comparison of monocultures of perennial sow-thistle and spring barley in estimated shoot radiation-use and nitrogen-uptake efficiencies

Shoot radiation-use efficiency (RUE) and nitrogen-uptake efficiency (UPE) of monocultures of perennial sow-thistle (Sonchus arvensis L.) and spring barley (Hordeum distichon L.) were quantified to assess the significance of these traits for the relative performance of the two species. RUE and UPE were derived for shoot growth and N uptake by calibrating a mechanistic model to above-ground biomass and N observations in an outdoor box experiment, conducted during two years at two soil nitrogen levels in Central Sweden. The model, which is driven by climate variables, predicts above-ground biomass and nitrogen increment as a function of intercepted radiation, temperature, and nitrogen availability. Observed values of leaf area and root development are used as input. Shoot RUE in S. arvensis was only 56% of the RUE in spring barley (1.35 and 2.40 g dry weight MJ−1, respectively). On the other hand, shoot UPE in S. arvensis at low N supply during early season was seven times higher than in barley (0.07 and 0.01 d−1, respectively). For S. arvensis, UPE was higher at the low soil nitrogen level than at high level, while the reverse was found for barley, at a given amount of biomass per area unit. We suggest that the higher shoot UPE in S. arvensis at low nitrogen supply, in comparison with the low UPE of annual small grain crops at low soil nitrogen levels, is a contributing cause for the observed increase in S. arvensis in organic farming.

Increased tree carbon storage in response to nitrogen deposition in the US

Spatially extensive evidence for nitrogen-induced stimulation of forest growth has been lacking. Analysis of forest inventory data from the northeastern and north-central US collected during the 1980s and 1990s indicates that nitrogen deposition enhanced above-ground carbon storage by 61 kg per kg of nitrogen deposited. Human activities have greatly accelerated emissions of both carbon dioxide and biologically reactive nitrogen to the atmosphere1,2. As nitrogen availability often limits forest productivity3, it has long been expected that anthropogenic nitrogen deposition could stimulate carbon sequestration in forests4. However, spatially extensive evidence for deposition-induced stimulation of forest growth has been lacking, and quantitative estimates from models and plot-level studies are controversial5,6,7,8,9,10. Here, we use forest inventory data to examine the impact of nitrogen deposition on tree growth, survival and carbon storage across the northeastern and north-central USA during the 1980s and 1990s. We show a range of growth and mortality responses to nitrogen deposition among the region’s 24 most common tree species. Nitrogen deposition (which ranged from 3 to 11 kg ha−1 yr−1) enhanced the growth of 11 species and decreased the growth of 3 species. Nitrogen deposition enhanced growth of all tree species with arbuscular mycorrhizal fungi associations. In the absence of disturbances that reduced carbon stocks by more than 50%, above-ground biomass increment increased by 61 kg of carbon per kg of nitrogen deposited, amounting to a 40% enhancement over pre-industrial conditions. Extrapolating to the globe, we estimate that nitrogen deposition could increase tree carbon storage by 0.31 Pg carbon yr−1.

Carbono e nutrientes na biomassa aérea arbórea, vegetação sob coberto e solo numa cronossequência de povoamentos de pinhal bravo

Biomass and nutrient amounts accumulated in the above ground biomass along the rotation period of maritime pine stands of the Leiria National Forest were evaluated. Amounts of biomass and nutrients of understory were also assessed. Furthermore, mass and nutrients in organic soil layers, as well as nutrient amounts in mineral soil layers (up to 100 cm depth) were evaluated. A strong increment of above ground biomass and accumulated nutrients was observed along the rotation period, with maximum at the end. A similar increment of organic C and nutrients was also observed in the mineral soil layers in the later rotation stage, being mostly allocated to the top soil layers (0-20 cm). Organic C was equally distributed by the above ground biomass and mineral soil, while N and Ca were mostly allocated to the soil. Phosphorus was largely allocated to the organic soil layers and harvest residues, and Mg and K showed an intermediate pattern. Results suggest that system disturbances associated with stand exploitation (harvesting, log removal, harvest residues removal, microclimate changes) may provoke strong variations on the organic C stock and nutrient availability. Proper site management to avoid organic matter and nutrient losses are crucial to assure system sustainability.