Effects of fire severity and season of burn on Betula glandulosa growth dynamics

2004 ◽  
Vol 13 (3) ◽  
pp. 287 ◽  
Author(s):  
William J. de Groot ◽  
Ross W. Wein
Keyword(s):  
Field Experiments ◽  
Fire Severity ◽  
Growth Dynamics ◽  
Fire Regimes ◽  
Height Growth ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
High Soil Moisture ◽  
Wide Range ◽  
Betula Glandulosa

Betula glandulosa survives over a wide range of North American fire regimes by resprouting from the rhizome. Over-winter root carbohydrate reserves are important to sprout production and growth in the following spring. Nursery and field experiments were conducted to examine the effects of seasonal clipping and fire severity (lethal heat applied to different soil depths) on B. glandulosa sprouting and growth, and seasonal burning and clipping on over-winter root carbohydrate storage. Low fire severity increased sprout numbers, and low fire severity in spring caused a large increase in height growth and above-ground biomass production over a 2-year period. Mortality rates increased sharply with higher levels of fire severity. Over-winter total non-structural carbohydrate (TNC) concentrations in roots were significantly higher in plants burned immediately after leaf-flush than in mid-summer burned plants. None of the other seasonal burning or clipping treatments significantly influenced over-winter root TNC. Post-disturbance sprout growth reflected over-winter root TNC levels. B. glandulosa survives a wide range of fire frequencies by growing in plant communities that are most likely to burn in spring or autumn, and seldom burn in summer. This provides the greatest opportunity for maximum over-winter TNC storage. As well, high soil moisture after snowmelt ensures spring fires are almost always of low severity, which promotes increased sprout production, height growth and above-ground biomass.

scholarly journals Systemic Colonization by Metarhizium robertsii Enhances Cover Crop Growth

2020 ◽  
Vol 6 (2) ◽  
pp. 64
Author(s):  
Imtiaz Ahmad ◽  
María del Mar Jiménez-Gasco ◽  
Dawn S. Luthe ◽  
Mary E. Barbercheck
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Field Experiments ◽  
Negative Relationship ◽  
Crop Growth ◽  
Above Ground Biomass ◽  
Crop Species ◽  
Metarhizium Robertsii ◽  
Cereal Rye ◽  
Ground Biomass

Fungi in the genus Metarhizium (Hypocreales: Clavicipitaceae) are insect pathogens that can establish as endophytes and can benefit their host plant. In field experiments, we observed a positive correlation between the prevalence of M. robertsii and legume cover crops, and a negative relationship with brassicaceous cover crops and with increasing proportion of cereal rye in mixtures. Here, we report the effects of endophytic M. robertsii on three cover crop species under greenhouse conditions. We inoculated seeds of Austrian winter pea (Pisum sativum L., AWP), cereal rye (Secale cereale L.), and winter canola (Brassica napus L.) with conidia of M. robertsii to assess the effects of endophytic colonization on cover crop growth. We recovered M. robertsii from 59%, 46%, and 39% of seed-inoculated AWP, cereal rye, and canola plants, respectively. Endophytic M. robertsii significantly increased height and above-ground biomass of AWP and cereal rye but did not affect chlorophyll content of any of the cover crop species. Among inoculated plants from which we recovered M. robertsii, above-ground biomass of AWP was positively correlated with the proportion of colonized root but not leaf tissue sections. Our results suggest that winter cover crops may help to conserve Metarhizium spp. in annual cropping systems.

INTERACTION EFFECTS BETWEEN WATER HARVESTING TECHNIQUES AND SPACING ON GRAIN YIELD AND ABOVE GROUND BIOMASS OF COWPEA

2017 ◽  
Vol 2 (1) ◽  
pp. 58-69
Author(s):  
Armara Macimiliam Galwab ◽  
Prof. Peter Kamau
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Block Design ◽  
Interaction Effects ◽  
Growth And Yield ◽  
Water Harvesting ◽  
Unique Contribution ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Harvesting Techniques

Purpose: The purpose of this study was to determine the interaction effects between  water harvesting techniques and spacing on grain yield and above ground biomass of cowpea.Methodology: A randomized complete block design was used. Field experiments were conducted. The study was conducted at Agriculture demonstration farm (Dakabaricha) and Yayo’s farm(Nagayo) and a private farm Demo farm. There were 18 treatment combinations consisting of three water harvesting techniques and two intra-row spacing.Results: The use of tied ridges (W3/S2) as the first and open ridges (W2/S1) as the second efficient techniques of water harvesting for this specific condition (Arid and semi-arid). In line with the above ground biomass, tied ridges with a spacing of 60 x 20cm planting could be safely recommended as the first and effective type of water harvesting techniques for use as a means of soil and water conservation for rain-fed cowpea under the prevailing conditions. The results of the study also showed that water harvesting techniques had a significant effect on the growth and yield of cowpea (Katumani K80).Unique  Contribution to Theory, Practice and Policy: Farmers are encourage to give more emphasis to water harvesting techniques in situ and drought tolerant crops (DTC) which are high yielding in order to bost the economic of the resource poor residence in the area through capacity building. An assessment of adaptation of more cowpea genotypes at different environments across years is recommended. The investigation provided sufficiently evidence to continue with further studies. 

scholarly journals Biomass and dominance of conservative species drive above-ground biomass productivity in a mediterranean-type forest of Chile

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Ariel Isaías Ayma-Romay ◽  
Horacio E. Bown
Keyword(s):  
Biomass Productivity ◽  
Well Being ◽  
Mediterranean Forests ◽  
Mass Ratio ◽  
Above Ground Biomass ◽  
Niche Complementarity ◽  
Soil Resources ◽  
Ground Biomass ◽  
Wide Range ◽  
Chilean Matorral

Abstract Background Forest productivity has a pivotal role in human well-being. Vegetation quantity, niche complementarity, mass-ratio, and soil resources are alternative/complementary ecological mechanisms driving productivity. One challenge in current forest management depends on identifying and manipulating these mechanisms to enhance productivity. This study assessed the extent to which these mechanisms control above-ground biomass productivity (AGBP) of a Chilean mediterranean-type matorral. AGBP measured as tree above-ground biomass changes over a 7-years period, was estimated for twelve 25 m × 25 m plots across a wide range of matorral compositions and structures. Variables related to canopy structure, species and functional diversity, species and functional dominance, soil texture, soil water and soil nitrogen content were measured as surrogates of the four mechanisms proposed. Linear regression models were used to test the hypotheses. A multimodel inference based on the Akaike’s information criterion was used to select the best models explaining AGBP and for identifying the relative importance of each mechanism. Results Vegetation quantity (tree density) and mass-ratio (relative biomass of Cryptocarya alba, a conservative species) were the strongest drivers increasing AGBP, while niche complementarity (richness species) and soil resources (sand, %) had a smaller effect either decreasing or increasing AGBP, respectively. This study provides the first assessment of alternative mechanisms driving AGBP in mediterranean forests of Chile. There is strong evidence suggesting that the vegetation quantity and mass-ratio mechanisms are key drivers of AGBP, such as in other tropical and temperate forests. However, in contrast with other studies from mediterranean-type forests, our results show a negative effect of species diversity and a small effect of soil resources on AGBP. Conclusion AGBP in the Chilean matorral depends mainly on the vegetation quantity and mass-ratio mechanisms. The findings of this study have implications for matorral restoration and management for the production of timber and non-timber products and carbon sequestration.

Early regeneration and growth dynamics of Populus tremuloides suckers in relation to fire severity

2003 ◽  
Vol 33 (10) ◽  
pp. 1998-2006 ◽  
Author(s):  
G. Geoff Wang
Keyword(s):  
Populus Tremuloides ◽  
Fire Severity ◽  
Growth Dynamics ◽  
Basal Area ◽  
Height Growth ◽  
Analysis Of Covariance ◽  
Total Variance ◽  
First Year ◽  
The Third ◽  
Early Regeneration

Four boreal mixedwood stands burned by the 1999 Black River wildfire in southeastern Manitoba were sampled to determine the effect of fire severity on density and diameter and height growth of trembling aspen (Populus tremuloides Michx.) suckers during the first three postfire years. Analysis of covariance, using prefire aspen basal area as the covariate, indicated that fire severity significantly affected postfire aspen sucker density, with significantly lower density found on severely burned plots. Changes in aspen sucker density over the three postfire years depended on fire severity, with significant changes observed only on scorched and lightly burned plots. Sucker mortality was positively related to the initial sucker density, with more than 80% of the total variance being explained. Fire severity significantly affected the growth of dominant aspen suckers in the first, but not the second and the third, postfire years. The first year of growth initially increased and then remained stable with the increase in density, while the second and third years of growth were not affected by density. Since fire severity within and (or) among burned stands is inherently heterogeneous, the effect of fire severity must be taken into account in predicting postfire density and growth of aspen suckers.

scholarly journals EFFECT OF SPACING ON GRAIN YIELD AND ABOVE GROUND BIOMASS OF COWPEA

2017 ◽  
Vol 1 (1) ◽  
pp. 24
Author(s):  
Armara Macimiliam Galwab ◽  
Prof. Peter Kamau
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Block Design ◽  
Water Harvesting ◽  
Unique Contribution ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Randomized Complete Block Design ◽  
Harvesting Techniques ◽  
Private Farm

Purpose: The purpose of this study was to determine the effect of spacing on grain yield and above ground biomass of cowpea. Methodology: A randomized complete block design was used. Field experiments were conducted. The study was conducted at Agriculture demonstration farm (Dakabaricha) and Yayo’s farm(Nagayo) and a private farm Demo farm. There were 18 treatment combinations consisting of three water harvesting techniques and two intra-row spacing. Results:Tied ridges with cross bars at 2.5m interval with the spacing of 60 x 20cm (W3 /S1) and open ridges with a spacing of 60 x 20cm (W3/S1) recorded the highest grain yield of 1408 kg/ha and 1296 kg/ha respectively. Unique  Contribution to Theory, Practice and Policy:An assessment of adaptation of more cowpea genotypes at different environments across years is recommended. The investigation provided sufficiently evidence to continue with further studies.

scholarly journals Novel UAV-based tools for assessing coastal grassland structure and function 

2021 ◽  
Author(s):  
Miguel Villoslada ◽  
Thaisa Bergamo ◽  
Raymond Ward
Keyword(s):  
Ecosystem Services ◽  
Random Forest ◽  
Plant Communities ◽  
Spatial Configuration ◽  
Mean Shift ◽  
Ecosystem Structure ◽  
Above Ground Biomass ◽  
Random Forest Algorithm ◽  
Ground Biomass ◽  
Wide Range

<p>Coastal grasslands provide a wide range of ecosystem services worldwide. In order to better target conservation efforts in these ecosystems, it is necessary to develop highly accurate models that account for the spatial nature of ecosystem structure, processes and functions. Here, we present a novel set of UAV-based tools to accurately assess and map coastal grassland structure and functions. Firstly, a combination of UAV-derived datasets were used to produce vegetation indices and micro topographic models. A classification random forest algorithm was used to process the spectral and microtopography datasets and map the extent and spatial configuration of plant communities in coastal meadows in Estonia. The model accurately predicted the occurrence of plant communities with a very high kappa value.</p><p>In the second stage, a regression random forest algorithm was used to model and map above-ground biomass within the coastal grasslands sites. Subsequently, the above-ground biomass maps in combination with a mean-shift algorithm were used to assess grassland structural heterogeneity. The results were then related to management history at each study site, showing that continuous, monospecific grazing management tends to simplify grassland structure, which could in turn reduce the supply of a key regulation and maintenance ecosystem services: nursery and reproduction habitat for waders.</p><p>These results also indicate that UAV-based surveys can serve as reliable grassland monitoring tools and could aid in the development of site-specific management strategies.</p>

Betula glandulosa Michx. Response to burning and postfire growth temperature and implications of climate change

1999 ◽  
Vol 9 (1) ◽  
pp. 51 ◽  
Author(s):  
W. J. de Groot ◽  
Ross W. Wein
Keyword(s):  
Climate Change ◽  
Growth Temperature ◽  
Fire Ecology ◽  
Fire Severity ◽  
Height Growth ◽  
Future Climate Change ◽  
Separate Analysis ◽  
Individual Site ◽  
Betula Glandulosa ◽  
Growing Conditions

Plants collected from eight fire-prone sites in western and northern Canada were tested in a greenhouse experiment for response to low fire severity and growing temperatures of 14-24˚C. The combined data showed that burning interacted with growth temperature during the first 42 days after treatment to significantly reduce sprout height at low temperatures and increase sprout height at the highest temperature. Burning significantly increased sprout height growth at all temperature treatments after 84 days although this effect was most apparent at the highest growth temperature. Burning significantly reduced sprout production after 42 days and had no significant influence on sprout production or aboveground biomass production after 84 days. Separate analysis of individual site data showed two populations with significant fire-stimulated sprout height growth and two other populations with similar, but slightly less significant response. The populations showed no geographic or topographic trend in fire response. The warmer growing conditions of postfire microsites appear to provide this shade intolerant plant with a competitive advantage over other invading pioneer and resprouting species by enhancing fire-stimulated height growth response. Due to its fire ecology, Betula glandulosa populations are expected to expand and thrive in this region under future climate change conditions.

Tree above-ground biomass dynamics in the Northeast Siberian tundra-taiga from nowadays to 3000 AD

2021 ◽  
Author(s):  
Iuliia Shevtsova ◽  
Ulrike Herzschuh ◽  
Birgit Heim ◽  
Stefan Kruse
Keyword(s):  
Terrestrial Ecosystems ◽  
Mountainous Area ◽  
Above Ground Biomass ◽  
Study Region ◽  
High Spatial Resolution Image ◽  
Ground Biomass ◽  
Northern Border ◽  
Wide Range ◽  
Rcp 8.5 ◽  
Landsat Satellite

<p>Changes in future above-ground biomass (AGB) of terrestrial ecosystems is one of the current interests in the light of climate change and essential to forecast for predicting potential climate feedbacks such as influence on the carbon balance. The tundra-taiga ecotone is a region that is prone to notable above-ground biomass changes, in the first instance due to the treeline advance. Forest is expected to occupy non-polygonal tundra. Our study region in central Chukotka (Northeastern Siberia) is a mountainous area on the northern border of the tundra-taiga ecotone that covers a wide range of vegetation types on a density gradient starting with lichen communities via open graminoid tundra to forest tundra. There is only one tree species – a deciduous conifer Larix cajanderi. We applied the individual-based spatially explicit model LAVESI to simulate larch AGB change from nowadays to 3000 AD under different climate scenarios, depending on Representative Concentration Pathways (RCPs) RCP 2.6, RCP 4.5 and RCP 8.5. We implemented in the model topographical parameters, as well as region-specific individual larch AGB equations, biological parameters of the tree growth and climate variables. We validated the new version of the model against field and Landsat satellite-based data, as well as a high spatial resolution image with distinctive trees visible, provided by ESRI (ArcGIS/World_imagery). Our first results are indicating mostly densification of existing tree stands before 2200 AD and forest expansion in the study region after 2200 AD even under the mildest RCP 2.6 scenario. First evaluations of the average tree AGB increase rates from present to 2200 AD are ranges from 0.007 (RCP 2.6) to 0.01 (RCP 8.5) kg*m<sup>-2</sup>*yr<sup>-1</sup>. Obtained rates of tree AGB change and its future distribution on the landscape can be particularly useful for conservation measures and modelling of future above-ground carbon stock dynamics.</p>

scholarly journals Ground-Based LiDAR Improves Phenotypic Repeatability of Above-Ground Biomass and Crop Growth Rate in Wheat

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
David M. Deery ◽  
Greg J. Rebetzke ◽  
Jose A. Jimenez-Berni ◽  
Anthony G. Condon ◽  
David J. Smith ◽  
...  
Keyword(s):  
Growth Rate ◽  
Field Experiments ◽  
Crop Growth ◽  
Canopy Architecture ◽  
Above Ground Biomass ◽  
Discrete Events ◽  
Crop Growth Rate ◽  
Ground Biomass ◽  
Improvement Programs ◽  
Ground Based Lidar

Highly repeatable, nondestructive, and high-throughput measures of above-ground biomass (AGB) and crop growth rate (CGR) are important for wheat improvement programs. This study evaluates the repeatability of destructive AGB and CGR measurements in comparison to two previously described methods for the estimation of AGB from LiDAR: 3D voxel index (3DVI) and 3D profile index (3DPI). Across three field experiments, contrasting in available water supply and comprising up to 98 wheat genotypes varying for canopy architecture, several concurrent measurements of LiDAR and AGB were made from jointing to anthesis. Phenotypic correlations at discrete events between AGB and the LiDAR-derived biomass indices were significant, ranging from 0.31 (P<0.05) to 0.86 (P<0.0001), providing confidence in the LiDAR indices as effective surrogates for AGB. The repeatability of the LiDAR biomass indices at discrete events was at least similar to and often higher than AGB, particularly under water limitation. The correlations between calculated CGR for AGB and the LiDAR indices were moderate to high and varied between experiments. However, across all experiments, the repeatabilities of the CGR derived from the LiDAR indices were appreciably greater than those for AGB, except for the 3DPI in the water-limited environment. In our experiments, the repeatability of either LiDAR index was consistently higher than that of AGB, both at discrete time points and when CGR was calculated. These findings provide promising support for the reliable use of ground-based LiDAR, as a surrogate measure of AGB and CGR, for screening germplasm in research and wheat breeding.

scholarly journals Biochar Integration with Legume Crops in Summer Gape Synergizes Nitrogen Use Efficiency and Enhance Maize Yield

Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 58 ◽  
Author(s):  
Fazal Jalal ◽  
Muhammad Arif ◽  
Kashif Akhtar ◽  
Aziz Khan ◽  
Misbah Naz ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
N Use Efficiency ◽  
Mineral Fertilizers ◽  
Cropping Pattern ◽  
Above Ground Biomass ◽  
Mineral N ◽  
Ground Biomass ◽  
Use Efficiency ◽  
N Use

Besides carbon (C) sequestration, biochar (BC) is recently believed to deliver multiple eco-friendly benefits to the soil for enhancing crop productivity. Use of mineral fertilizers coupled with BC been suggested a promising sustainable strategy for increasing crops yield. However, imperative study is needed to investigate (1) BC integration with multiple legumes crop adjusted in summer gape for pooling more organic carbon and nitrogen, and (2) subsequently looking into its synergism with mineral N in the following crop. Therefore, two years’ field experiments were conducted on maize under cereal based cropping pattern with the adjustment of legumes (i.e., mungbean, cowpea, and Sesbania) with a fallow in summer. In legumes, treatments consist of (0 and 50 t ha−1) BC application. However, N rates of 0, 90, 120, 150 kg ha−1 were added to the subsequent maize crop. Preceding legumes plots with the use of 50 t ha−1 biochar enhanced maize grain yield, above ground biomass, stover N, grain N, soil C, and N content after maize harvest and N use efficiency as compared to non-legumes with BC and legumes without BC plots. N application increased grain yield, above-ground biomass, stover N, grain N, and soil N but reduced N use efficiency with higher rates. Conclusively, the integration of biochar and legumes is a promising option for increasing the entire farm production of cereal-based cropping systems. This increment in yield was associated with supplying a viable input of N and C to soil and increased yields from this supplementary ‘summer gap’ crop.

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