Seasonal growth and standing crop of Scirpus maritimus var. paludosus in Saskatchewan

1982 ◽  
Vol 60 (2) ◽  
pp. 117-125 ◽  
Author(s):  
V. J. Lieffers ◽  
Jennifer M. Shay
Keyword(s):  
Water Depth ◽  
Standing Crop ◽  
Late Summer ◽  
Water Levels ◽  
Stem Density ◽  
Total Biomass ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Growing Seasons ◽  
Scirpus Maritimus

Shoots of Scirpus maritimus var. paludosus sprout from overwintered tubers in May. Stem growth is rapid and within 2–3 weeks lateral rhizomes extend outwards and produce tillers with new tubers at their bases. By August up to four new shoots are produced in a rhizome–shoot series. All aboveground biomass is dead by late October but tubers overwinter to develop the following growing season. The ratio of below- to above-ground biomass of the rhizome–shoot series increased from 0.20 to 0.76 from early to late summer. The ratio of below- to above-ground biomass of individual stems was highest at the youngest end of the rhizome–shoot series.Stem density and inflorescence and total biomass were monitored at three sites over three growing seasons. The sites had large fluctuations in salinity in response to changes in water depth. Among all sites, maximum stem density reached 380 stems/m2 by late July, slightly before the maximum standing crop of 625 g/m2 was attained. At one site, changes in water levels and salinity increased the peak aboveground standing crop 22-fold (from 27 to 600 g/m2) from 1978 to 1979. A mathematical equation predicting the seasonal aboveground standing crop of S. maritimus was developed using water depth and conductivity as predictor variables.

Distribution and variation in growth of Scirpus maritimus var. paludosus on the Canadian prairies

1982 ◽  
Vol 60 (10) ◽  
pp. 1938-1949 ◽  
Author(s):  
V. J. Lieffers ◽  
Jennifer M. Shay
Keyword(s):  
Maximum Size ◽  
Water Levels ◽  
Stem Density ◽  
Total Biomass ◽  
Freshwater Species ◽  
Canadian Prairies ◽  
Mud Flat ◽  
Below Ground ◽  
Scirpus Maritimus ◽  
Upper Slope

Scirpus maritimus var. paludosus occurs in saline lakes in the prairie and parkland regions of Alberta, Saskatchewan, and Manitoba. Its distribution within wetlands is dependent upon the degree of salinity during germination and seedling establishment. In hypersaline wetlands, S. maritimus is found only on a narrow band on the upper slope of the basin; as these wetlands become dry, only the upper slope has mud flat salinities low enough to allow successful germination. In wetlands of the saline category, S. maritimus occurs over a broad area of the upper and middle slope, and in moderately saline wetlands it is usually outcompeted by freshwater species but may dominate the centre of the basin in low-water years. Canonical-correlation analysis of S. maritimus growth variables in 24 sites in Saskatchewan, Manitoba, and Alberta showed a large phenotypic growth response to different environmental conditions. On dry and highly saline sites, S. maritimus tubers developed short, and in most cases nonflowering, stems. In shallow water and reduced salinity, individual stems were larger and stem density and above-and below-ground biomass were at a maximum. In water greater than 40 cm deep and with low salinities, individual stems and inflorescences reached maximum size, but the much lower stem density resulted in reduced total biomass. Seed production was also influenced by the previous year's water levels. At those sites which were dry and then flooded the next year, more stems flowered and inflorescences were larger than at sites which had been flooded continuously the previous year.

Legumes intercropped with spring barley contribute to increased biomass production and carry-over effects

2011 ◽  
Vol 150 (5) ◽  
pp. 584-594 ◽  
Author(s):  
V. A. PAPPA ◽  
R. M. REES ◽  
R. L. WALKER ◽  
J. A. BADDELEY ◽  
C. A. WATSON
Keyword(s):  
Grain Yield ◽  
Spring Barley ◽  
N Uptake ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Growing Seasons ◽  
Sole Crop ◽  
Matter Production ◽  
Grain Crop ◽  
Carry Over

SUMMARYIntercropping systems that include legumes can provide symbiotically fixed nitrogen (N) and potentially increase yield through improved resource use efficiency. The aims of the present study were: (a) to evaluate the effects of different legumes (species and varieties) and barley on grain yield, dry matter production and N uptake of the intercrop treatments compared with the associated cereal sole crop; (b) to assess the effects on the yields of the next grain crop and (c) to determine the accumulation of N in shoots of the crops in a low-input rotation. An experiment was established near Edinburgh, UK, consisting of 12 hydrologically isolated plots. Treatments were a spring barley (Hordeum vulgare cvar Westminster) sole crop and intercrops of barley/white clover (Trifolium repens cvar Alice) and barley/pea (Pisum sativum cvar Zero4 or cvar Nitouche) in 2006. All the plots were sown with spring oats (Avena sativa cvar Firth) in 2007 and perennial ryegrass in 2008. No fertilizers, herbicides or pesticides were used at any stage of the experiment. Above-ground biomass (barley, clover, pea, oat and ryegrass) and grain yields (barley, pea and oat) were measured at key stages during the growing seasons of 2006, 2007 and 2008; land equivalent ratio (LER) was measured only in 2006. At harvest, the total above-ground biomass of barley intercropped with clover (4·56 t biomass/ha) and barley intercropped with pea cvar Zero4 (4·49 t biomass/ha) were significantly different from the barley sole crop (3·05 t biomass/ha; P<0·05). The grain yield of the barley (2006) intercropped with clover (3·36 t grain/ha) was significantly greater than that in the other treatments (P<0·01). The accumulation of N in barley was low in 2006, but significantly higher (P<0·05) in the oat grown the following year on the same plots. The present study demonstrates for the first time that intercrops can affect the grain yield and N uptake of the following crop (spring oats) in a rotation. Differences were also linked to the contrasting legume species and cultivars present in the previous year's intercrop. Legume choice is essential to optimize the plant productivity in intercropping designs. Cultivars chosen for intercropping purposes must take into account the effects upon the growth of the partner crop/s as well as to the following crop, including environmental factors.

scholarly journals Grazing Exclusion, a Choice between Biomass Growth and Species Diversity Maintenance in Beijing—Tianjin Sand Source Control Project

2019 ◽  
Vol 11 (7) ◽  
pp. 1941 ◽  
Author(s):  
Yuzhe Li ◽  
Jiangwen Fan ◽  
Hailing Yu
Keyword(s):  
Species Diversity ◽  
Diversity Index ◽  
Source Control ◽  
Total Biomass ◽  
Above Ground Biomass ◽  
Grazing Exclusion ◽  
Ground Biomass ◽  
Wiener Diversity Index ◽  
Restoration Practices ◽  
Sand Source

Grasslands in northern China form an important ecological barrier that prevents and controls desertification. The Beijing–Tianjin Sand Source Control (BTSSC) Project has been implemented to restore grassland in order to control sand sourced pollution. This study aimed to understand the impacts of four applied restoration practices on the productivity, composition, and species diversity of vegetation communities in the BTSSC Project. The results indicated the following: (1) All the restoration practices tended to increase the height and cover of communities, and the effect was most obvious where grazing was excluded; (2) total biomass (87%), above-ground biomass (164%) and below-ground biomass (58%) only increased consistently when grazing was excluded from the steppe; (3) fenced and grazing exclusion practice significantly increased the abundance of species in communities, but all the practices tended to decrease the evenness of species; and, (4) the correlation analysis revealed that the Shannon–Wiener diversity index, and Pielou evenness index, showed significant negative correlations with the above-ground biomass of grassland communities after restoration, while no significant relationships were shown in reference plots. Our comparison of applied practices in the BTSSC project revealed that grazing exclusion might be a high priority for more successful restoration in this region.

Clover green manure productivity and weed suppression in an organic grain rotation

2016 ◽  
Vol 32 (5) ◽  
pp. 474-483 ◽  
Author(s):  
Katja Koehler-Cole ◽  
James R. Brandle ◽  
Charles A. Francis ◽  
Charles A. Shapiro ◽  
Erin E. Blankenship ◽  
...  
Keyword(s):  
Winter Wheat ◽  
White Clover ◽  
Green Manure ◽  
Red Clover ◽  
Late Summer ◽  
Weed Suppression ◽  
Grain Protein ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Sampling Times

AbstractGreen manure crops must produce high biomass to supply biological N, increase organic matter and control weeds. The objectives of our study were to assess above-ground biomass productivity and weed suppression of clover (Trifolium spp.) green manures in an organic soybean [Glycine max (L.) Merr.]-winter wheat (Triticum aestivum L.)-corn (Zea mays L.) rotation in eastern Nebraska in three cycles (2011–12, 2012–13, 2013–14). Treatments were green manure species [red clover (T. pratense L.) and white clover (T. repens L.)] undersown into winter wheat in March and green manure mowing regime (one late summer mowing or no mowing). We measured wheat productivity and grain protein at wheat harvest, and clover and weed above-ground biomass as dry matter (DM) at wheat harvest, 35 days after wheat harvest, in October and in April before clover termination. Winter wheat grain yields and grain protein were not affected by undersown clovers. DM was higher for red than for white clover at most sampling times. Red clover produced between 0.4 and 5.5 Mg ha−1 in the fall and 0.4–5.2 Mg ha−1 in the spring. White clover produced between 0.1 and 2.5 Mg ha−1 in the fall and 0.2–3.1 Mg ha−1 in the spring. Weed DM was lower under red clover than under white clover at most sampling times. In the spring, weed DM ranged from 0.0 to 0.6 Mg ha−1 under red clover and from 0.0 to 3.1 Mg ha−1 under white clover. Mowing did not consistently affect clover or weed DM. For organic growers in eastern Nebraska, red clover undersown into winter wheat can be a productive green manure with good weed suppression potential.

scholarly journals Have ozone effects on carbon sequestration been over-estimated? A new biomass response function for wheat

2014 ◽  
Vol 11 (4) ◽  
pp. 5511-5531
Author(s):  
H. Pleijel ◽  
H. Danielsson ◽  
D. Simpson ◽  
G. Mills
Keyword(s):  
Grain Yield ◽  
Response Function ◽  
Radiative Forcing ◽  
Ozone Exposure ◽  
Yield Response ◽  
Total Biomass ◽  
Response Functions ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Biomass Loss

Abstract. Elevated levels of tropospheric ozone can significantly impair the growth of crops. The reduced removal of CO2 by plants leads to higher atmospheric concentrations of CO2, enhancing radiative forcing. Ozone effects on economic yield, e.g. the grain yield of wheat (Triticum aestivum L.) are currently used to model effects on radiative forcing. However, changes in grain yield do not necessarily reflect changes in total biomass. Based on analysis of 21 ozone exposure experiments with field-grown wheat, we investigated whether use of effects on grain yield as a~proxy for effects on biomass under- or over-estimates effects on biomass. First, we confirmed that effects on partitioning and biomass loss are both of significant importance for wheat yield loss. Then we derived ozone dose response functions for biomass loss and for harvest index (the proportion of above-ground biomass converted to grain) based on twelve experiments and recently developed ozone uptake modelling for wheat. Finally, we used a European scale chemical transport model (EMEP MSC-West) to assess the effect of ozone on biomass (−9%) and grain yield (−14%) loss over Europe. Based on yield data per grid square, we estimated above ground biomass losses due to ozone in 2000 in Europe totalling 22.2 million tonnes. Incorrectly applying the grain yield response function to model effects on biomass instead of the biomass response function of this paper would have indicated total above ground biomass losses totalling 38.1 million (i.e. overestimating effects by 15.9 million tonnes). A key conclusion from our study is that future assessments of ozone induced loss of agroecosystem carbon storage should use response functions for biomass, such as that provided in this paper, not grain yield, to avoid overestimation of the indirect radiative forcing from ozone effects on crop biomass accumulation.

scholarly journals Diversity, Population Structure, and Above Ground Biomass in Woody Species on Ngomakurira Mountain, Domboshawa, Zimbabwe

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Clemence Zimudzi ◽  
Christopher Chapano
Keyword(s):  
Small Diameter ◽  
Basal Area ◽  
Woody Species ◽  
Distribution Patterns ◽  
Wiener Index ◽  
Mean Value ◽  
Stem Density ◽  
Above Ground Biomass ◽  
Systematic Random Sampling ◽  
Ground Biomass

The diversity, structure, species composition, and above ground biomass of woody plants on Ngomakurira mountain in Zimbabwe were studied. A systematic random sampling approach was adopted to establish 52 sampling plots measuring 10 × 10 m across 3 study strata in the 1266 ha study area. Woody species occurring in each plot were identified and the circumferences of trees with diameters >8.0 cm at 1.3 m height were measured. A total of 91 species belonging to 74 genera and 39 families were identified in the sample plots. A Shannon-Wiener index mean value of 3.12 was obtained indicating high species diversity on the mountain. The DBH size class distribution showed inverse J distribution patterns across the three study strata, but with only 3 individual plants with DBH > 30 cm. Mean basal area was 15.21 m2 ha−1 with U. kirkiana and J. globiflora contributing approximately 30% of the basal area. The estimated above ground biomass ranged from 34.5 to 65.1 t ha−1. Kruskal-Wallis-H test showed no significant differences in species richness, stem density, basal area, above ground biomass, and evenness, across the study strata (p<0.05). Ngomakurira woodland has potential to regenerate due to the presence of many stems in the small diameter size classes.

scholarly journals Structure and biomass accumulation of natural mangrove forest at Gazi Bay, Kenya

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
JAMES G. KAIRO ◽  
MICHAEL NJOROGE GITHAIGA ◽  
KIPLAGAT KOTUT ◽  
FRANCIS KARIUKI
Keyword(s):  
Forest Structure ◽  
Mangrove Forest ◽  
Biomass Accumulation ◽  
Shoot Biomass ◽  
Total Biomass ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Significant Difference ◽  
Below Ground ◽  
Gazi Bay

Abstract. Githaiga MN, Kotut K, Kariuki F, Kairo JG. 2019. Structure and biomass accumulation of natural mangrove forest at Gazi Bay, Kenya. Bonorowo Wetlands 9: 18-32. The goal of this study was to determine the forest structure and estimate biomass accumulation above and below ground in the mangrove forest of Gazi Bay. The western, middle, and eastern forest blocks of the Gazi Bay mangrove forest were investigated for forest structure, whereas the western forest block was determined for biomass accumulation. To calculate below-ground biomass accumulation, in-growth cores of 80 cm long, 20 cm broad, and 60 cm deep were employed. Above-ground biomass accumulation was calculated using data on tree height and stem diameter at breast height (DBH-130). Leaf phenology was observed by tagging shoots. At the start, environmental variables were measured every four months for a year across four mangrove species zones. The linear regeneration sampling approach was used to determine the composition and distribution pattern of natural regeneration (LRS). Salinity revealed a strong negative connection with above-ground biomass accumulation among the soil environment characteristics studied. Sonneratia alba had the highest biomass accretion rate of 10.5 1.9 t ha-1 yr-1 among the four forest zones. Rhizophora mucronata (8.5 0.8 t ha-1 yr-1), Avicennia marina (5.2 1.8 t ha-1 yr-1), and Ceriops tagal (2.6 1.5 t ha-1 yr-1) were the next most abundant species. Above-ground and below-ground biomass accumulation differed significantly among zones (F (3, 8) = 5.42, p = 0.025) and (F (3, 8) = 16.03, p = 0 001), respectively. There was a significant difference in total biomass accumulation across zones (F (3, 8) =15.56, p = 0.001). For the entire forest, a root : shoot biomass accumulation ratio of 2 : 5 was calculated. This study's findings provide more accurate estimates of mangrove carbon capture and storage, which can be used in carbon credit discussions in the emerging carbon market.

scholarly journals Self-reseeding annual legumes for cover cropping in rainfed managed olive orchards

2015 ◽  
Vol 13 (2) ◽  
pp. e0302 ◽  
Author(s):  
M. Ângelo Rodrigues ◽  
Isabel Q. Ferreira ◽  
Sara L. Freitas ◽  
Jaime M. Pires ◽  
Margarida P. Arrobas
Keyword(s):  
Cover Crops ◽  
Soil Protection ◽  
Winter Period ◽  
Above Ground Biomass ◽  
Cover Cropping ◽  
Annual Legumes ◽  
Ground Biomass ◽  
Growing Seasons ◽  
Early Maturing ◽  
N Demand

<span lang="EN-US">Given the environmental impact of nitrogen (N)-fertilizer manufacture and use, the sustainable management of agro-systems should be sought by growing N-fixing legumes. In this work, eleven self-reseeding annual legumes were grown in pure stands as mulching cover crops in a rainfed olive orchard managed without grazing animals. Dry matter yield, N content in above-ground biomass, groundcover percentage and persistence of the sown species were assessed during four growing seasons. All covers provided enough soil protection over the year, with living plants during the autumn/winter period and a mulch of dead residues during the summer. The legumes overcame a false break observed in the third year recovering the dominance of the covers in the fourth growing season. This means that the seed bank established in previous seasons ensured the persistence of the sown legume even when a gap in seed production occurred. The early-maturing cultivars produced less biomass and fixed less N (approx. 50 kg N/ha/yr present in the above-ground biomass) than the late-maturing ones, but would compete less for water since the growing cycle finished earlier in the spring. They seem best suited to being grown in dry farmed olive orchards with low N demand in drought prone regions.<br /></span>

scholarly journals Biomass equations for calabrian pine in the mediterranean region of Turkey

2016 ◽  
Vol 140 (11-12) ◽  
pp. 567-576 ◽  
Author(s):  
Turan Sönmez ◽  
Mehmet Yavuz ◽  
Abdurrahman Şahin ◽  
Aydin Karhiman
Keyword(s):  
Mediterranean Region ◽  
Tree Height ◽  
Stem Bark ◽  
Allometric Equations ◽  
Total Biomass ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Calabrian Pine ◽  
Biomass Equations ◽  
The Mediterranean

The aim of this study was to develop allometric equations for the estimation of above-ground biomass components of Calabrian pine (Pinus brutia Ten.) tree in the Mediterranean Region of Turkey. Using regression analysis, different allometric equations were fitted for the tree components of the above-ground biomass using diameter at breast height (dbh) and tree height as estimators. Two hundred and ninety-two trees between 0.4 and 63.0 cm in dbh were randomly sampled throughout 292 natural, pure Calabrian pine stands in Turkey’s Mediterranean Region, where it forms diverse stand structures. Finally, the allometric equations were developed for the tree components of the Calabrian pine tree for the stem, bark, branch, needle and total above-ground biomass. The stem, bark and total biomass equations explained more than 90% of the observed variability, while the branch and needle biomass equations explained 82% and 65%, respectively.

scholarly journals Have ozone effects on carbon sequestration been overestimated? A new biomass response function for wheat

2014 ◽  
Vol 11 (16) ◽  
pp. 4521-4528 ◽  
Author(s):  
H. Pleijel ◽  
H. Danielsson ◽  
D. Simpson ◽  
G. Mills
Keyword(s):  
Grain Yield ◽  
Response Function ◽  
Radiative Forcing ◽  
Ozone Exposure ◽  
Yield Response ◽  
Total Biomass ◽  
Response Functions ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Biomass Loss

Abstract. Elevated levels of tropospheric ozone can significantly impair the growth of crops. The reduced removal of CO2 by plants leads to higher atmospheric concentrations of CO2, enhancing radiative forcing. Ozone effects on economic yield, e.g. the grain yield of wheat (Triticum aestivum L.), are currently used to model effects on radiative forcing. However, changes in grain yield do not necessarily reflect changes in total biomass. Based on an analysis of 22 ozone exposure experiments with field-grown wheat, we investigated whether the use of effects on grain yield as a proxy for effects on biomass under- or overestimates effects on biomass. First, we confirmed that effects on partitioning and biomass loss are both of significant importance for wheat yield loss. Then we derived ozone dose response functions for biomass loss and for harvest index (the proportion of above-ground biomass converted to grain) based on 12 experiments and recently developed ozone uptake modelling for wheat. Finally, we used a European-scale chemical transport model (EMEP MSC-West) to assess the effect of ozone on biomass (−9%) and grain yield (−14%) loss over Europe. Based on yield data per grid square, we estimated above-ground biomass losses due to ozone in 2000 in Europe, totalling 22.2 million tonnes. Incorrectly applying the grain yield response function to model effects on biomass instead of the biomass response function of this paper would have indicated total above-ground biomass losses totalling 38.1 million (i.e. overestimating effects by 15.9 million tonnes). A key conclusion from our study is that future assessments of ozone-induced loss of agroecosystem carbon storage should use response functions for biomass, such as that provided in this paper, not grain yield, to avoid overestimation of the indirect radiative forcing from ozone effects on crop biomass accumulation.

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