scholarly journals Chemical and mechanical control of the invasive shrub Cytisus scoparius in forest clearings in western Washington, USA

2020 ◽  
Vol 13 (1) ◽  
pp. 30-36
Author(s):  
Karen A. Haubensak ◽  
Sara Grove ◽  
Jeffrey Foster ◽  
Ingrid M. Parker
Keyword(s):  
Seed Germination ◽  
Large Scale ◽  
Soil Surface ◽  
Soil Disturbance ◽  
Percent Cover ◽  
Control Methods ◽  
Cytisus Scoparius ◽  
Invasive Shrub ◽  
Soil Scarification ◽  
Western Washington

AbstractWe conducted a large-scale, multiple-year study in harvested areas of Douglas-fir (Pseudotsuga menziesii [Mirbel] Franco) forests in western Washington, examining the effectiveness of control methods on the widespread invasive shrub Scotch broom [Cytisus scoparius (L.) Link]. We tested both chemical and physical control methods, using three different approaches that are management relevant: (1) triclopyr, a POST herbicide, at different times of year and on different-sized plants; (2) cutting (or brushcutting) of mature individuals; and (3) scarification of soil surface to remove seedlings once versus multiple times. We measured initial mortality, seed germination, and percent cover of C. scoparius in plots for 3 yr following treatments. Triclopyr treatment resulted in greater mortality and reduced percent cover compared with all other treatments with the effect persisting for 2 yr after spraying. Further, triclopyr had the same effect on C. scoparius cover and mortality irrespective of time of year applied. Similar to soil scarification, triclopyr treatments resulted in a flush of seedlings, suggesting that removal of conspecific competitors and not soil disturbance per se promotes seed germination. Brushcutting was generally effective in reducing C. scoparius cover in the short term, but effects did not persist as long as triclopyr treatments, in part due to large differences in stump resprouting rates across sites. Soil scarification to remove seedlings, even over multiple years, did not result in reduced C. scoparius cover. Triclopyr is an effective approach for controlling both emerging and established stands of C. scoparius.

Coal mining-disturbed land reclamation laws

2020 ◽  
pp. 15-26
Author(s):  
T. V. Galanina ◽  
M. I. Baumgarten ◽  
T. G. Koroleva
Keyword(s):  
Large Scale ◽  
Land Reclamation ◽  
Mining Industry ◽  
Development Program ◽  
Soil Disturbance ◽  
Open Pit ◽  
Open Pit Mining ◽  
Disturbed Land ◽  
Critical Problems ◽  
Production Output

Large-scale mining disturbs wide areas of land. The development program for the mining industry, with an expected considerable increase in production output, aggravates the problem with even vaster territories exposed to the adverse anthropogenic impact. Recovery of mining-induced ecosystems in the mineral-extracting regions becomes the top priority objective. There are many restoration mechanisms, and they should be used in integration and be highly technologically intensive as the environmental impact is many-sided. This involves pollution of water, generation of much waste and soil disturbance which is the most typical of open pit mining. Scale disturbance of land, withdrawal of farming land, land pollution and littering are critical problems to the solved in the first place. One of the way outs is highquality reclamation. This article reviews the effective rules and regulations on reclamation. The mechanism is proposed for the legal control of disturbed land reclamation on a regional and federal level. Highly technologically intensive recovery of mining-induced landscape will be backed up by the natural environment restoration strategy proposed in the Disturbed Land Reclamation Concept.

scholarly journals Impact of Weed Control by Hand Tools on Soil Erosion under a No-Tillage System Cultivation

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 974
Author(s):  
Rafael Blanco-Sepúlveda ◽  
Amilcar Aguilar-Carrillo ◽  
Francisco Lima
Keyword(s):  
Soil Erosion ◽  
Weed Control ◽  
Soil Cover ◽  
Soil Surface ◽  
Conservation Agriculture ◽  
Soil Disturbance ◽  
No Tillage ◽  
Tropical Mountains ◽  
Litter Cover ◽  
Vegetal Cover

In conservation agriculture, the no-tillage cultivation system and the retention of permanent vegetal cover are crucial to the control of soil erosion by water. This paper analyses the cultivation of maize under no-tillage, with particular reference to the effect produced on soil erosion when weed control is performed by a hand tool (machete), which disturbs the surface of the soil, and to the behavior of the soil cover in these circumstances. The study area is located in the humid tropical mountains of northern Nicaragua (Peñas Blancas Massif Nature Reserve). The results obtained show that 59.2% of the soil surface was affected by appreciable levels of sheet and splash erosion, although the vegetal cover of the soil was relatively high (with average weed and litter cover of 33.9% and 33.8%, respectively). The use of machetes for weed control provoked considerable soil disturbance, which explained the high rates of erosion observed. Moreover, this form of soil management disturbs the litter layer, making it less effective in preventing erosion. The litter remains loose on the soil surface, and so an increase in soil cover does not achieve a proportionate reduction in the area affected by erosion; thus, even with 80–100% weed and litter cover, 42% of the cultivated area continued to present soil erosion.

scholarly journals Factors affecting Cyperus difformis seed germination and seedling emergence

2013 ◽  
Vol 31 (4) ◽  
pp. 823-832 ◽  
Author(s):  
A. Derakhshan ◽  
J. Gherekhloo
Keyword(s):  
Seed Germination ◽  
Integrated Management ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Soil Surface ◽  
Weed Species ◽  
Factors Affecting ◽  
Cyperus Difformis ◽  
Emergence Patterns

Specific knowledge about the dormancy, germination, and emergence patterns of weed species aids the development of integrated management strategies. Laboratory studies were conducted to determine the effect of several environmental factors on seed germination and seedling emergence of Cyperus difformis. Germination of freshly harvested seeds was inhibited by darkness; however, when seeds were subsequently transferred to complete light they germinated readily. Our results showed that 2 wk of cold stratification overcome the light requirement for germination. Seeds of C. difformis were able to germinate over a broad range of temperatures (25/15, 30/20, 35/25, and 40/30 ºC day/night). The response of germination rate to temperature was described as a non-linear function. Based on model outputs, the base, the optimum and the ceiling temperatures were estimated as 14.81, 37.72 and 45 ºC, respectively. A temperature of 120 ºC for a 5 min was required to inhibit 50% of maximum germination. The osmotic potential and salinity required for 50% inhibition of maximum germination were -0.47 MPa and 135.57 mM, respectively. High percentage of seed germination (89%) was observed at pH=6 and decreased to 12% at alkaline medium (pH 9) pH. Seeds sown on the soil surface gave the greatest percentage of seedling emergence, and no seedlings emerged from seeds buried in soil at depths of 1 cm.

Accumulation patterns of soil organic matter in forests as a legacy of historical charcoal burning

2021 ◽  
Author(s):  
Anna Schneider ◽  
Alexander Bonhage ◽  
Florian Hirsch ◽  
Alexandra Raab ◽  
Thomas Raab
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Large Scale ◽  
Soil Surface ◽  
Landscape Scale ◽  
Legacy Effects ◽  
Charcoal Production ◽  
Study Region ◽  
Land Use Legacies

<p>Human land use and occupation often lead to a high heterogeneity of soil stratigraphy and properties in landscapes within small, clearly delimited areas. Legacy effects of past land use also are also abundant in recent forest areas. Although such land use legacies can occur on considerable fractions of the soil surface, they are hardly considered in soil mapping and inventories. The heterogenous spatial distribution of land use legacy soils challenges the quantification of their impacts on the landscape scale. Relict charcoal hearths (RCH) are a widespread example for the long-lasting effect of historical land use on soil landscapes in forests of many European countries and also northeastern USA. Soils on RCH clearly differ from surrounding forest soils in their stratigraphy and properties, and are most prominently characterized by a technogenic substrate layer with high contents of charcoal. The properties of RCH soils have recently been studied for several regions, but their relevance on the landscape scale has hardly been quantified.</p><p>We analyse and discuss the distribution and ecological relevance of land use legacy soils across scales for RCH in the state of Brandenburg, Germany, with a focus on soil organic matter (SOM) stocks. Our analysis is based on a large-scale mapping of RCH from digital elevation models (DEM), combined with modelled SOM stocks in RCH soils. The distribution of RCH soils in the study region shows heterogeneity at different scales. The large-scale variation is related to the concentration of charcoal production to specific forest areas and the small-scale accumulation pattern is related to the irregular distribution of single RCH within the charcoal production fields. Considerable fractions of the surface area are covered by RCH soils in the major charcoal production areas within the study region. The results also show that RCH can significantly contribute to the soil organic matter stocks of forests, even for areas where they cover only a small fraction of the soil surface. The study highlights that considering land use legacy effects can be relevant for the results of soil mapping and inventories; and that prospecting and mapping land use legacies from DEM can contribute to improving such approaches.</p>

Residual Large Trees Influence Short-term Succession Following a Volcanic Eruption in a Valdivian Temperate Rainforest

2021 ◽  
Author(s):  
Lisa Hintz ◽  
Dylan Fischer ◽  
Nina Ferrari ◽  
Charlie M.S. Crisafulli
Keyword(s):  
Soil Surface ◽  
Bare Soil ◽  
Understory Vegetation ◽  
Percent Cover ◽  
Vegetative Cover ◽  
Vegetation Response ◽  
Temperate Rainforest ◽  
Large Trees ◽  
Close Proximity ◽  
Disturbed Forest

Abstract Airborne volcanic ejecta (tephra) can strongly influence forest ecosystems through initial disturbance processes and subsequent ecological response. Within a tephra-disturbed forest, large trees may promote plant growth and create favorable sites for colonization. Three primary ways trees can influence post-eruption vegetation response include: 1) amelioration of volcanic substrates, 2) as source propagules from the tree or from associated epiphytes, and 3) by sheltering understory vegetation, thereby increasing rate of recovery near tree bases. Here, we evaluate Valdivian temperate rainforest understory vegetation response and soil characteristics in close proximity to large trees that survived the 2015 eruption of Calbuco Volcano. Understory vegetative cover was higher near the base of trees for mosses, many epiphytes, and some herbaceous, shrub, and trees species. However, significant interactions with year of measurement, and individualistic responses by many species made generalizations more difficult. Small shrubs and trees in particular demonstrated patterns of recovery that were frequently independent of distance. In some cases, percent cover of colonizing vegetation actually increased far from trees by 2019. The soil surface was similarly variable where bare soil cover was associated with locations proximal to tree bases, but material shed from living and dead standing vegetation increased wood and litter abundances on the soil surface away from the base of trees. Soils near trees had lower pH, elevated organic matter, and higher nitrogen and carbon. Our results support the assertion that in this temperate rainforest ecosystem, large trees can modify edaphic conditions and provide important early refugia for vegetative regrowth following a tephra fall event. Nevertheless, complex interactions through time with species and growth form, suggest the influence of large trees on plant establishment and growth with close proximity tree boles is more complex than a simple facilitative model might suggest.

scholarly journals Epilithic community development on artificial reefs deployed along a cross-shelf environmental gradient off Paraná state, southern Brazil

2011 ◽  
Vol 59 (spe1) ◽  
pp. 43-53 ◽  
Author(s):  
Frederico Brandini ◽  
Ariel Scheffer da Silva
Keyword(s):  
Large Scale ◽  
Diversity Index ◽  
Artificial Reef ◽  
Larval Abundance ◽  
Percent Cover ◽  
Southern Brazil ◽  
Factors Affecting ◽  
Hydrographic Conditions ◽  
One Year ◽  
General Community

Concrete modules were deployed on the bottom of the 11, 18 and 30 meters isobaths along a cross-shelf hydrographic gradient off Paraná State, Southern Brazil, with the purpose of studying the colonization of sessile epilithic macroinvertebrates on artificial surfaces. After one year of submersion a total of 63 species of epilithic organisms were identified, dominated by Ostrea puelchana, Chthamalus bisinuatus, Balanus cf spongicola, Astrangia cf rathbuni, Didemnum spp, poryphers and bryozoans. Diversity index and percent cover at reef stations placed at 11, 18 and 30 meters isobaths were respectively 2.28 and 66.7%, 2.79 and 96.6% and 1.66 and 77.4%. Differences of general community structure among the three assemblages were not clearly related to the general environmental conditions at the bottom layers near the reef stations. Turbidity and larval abundance are discussed as important factors affecting colonization processes. Results indicate that depths between 15-20 meters are more suitable for the implementation of large scale artificial reef systems in the inner shelf off Paraná and, possibly, throughout the inner shelves off southern Brazil with similar hydrographic conditions.

Effect of Environmental Factors on Germination and Emergence of Shortawn Foxtail (Alopecurus aequalis)

Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Ning Zhao ◽  
Qi Li ◽  
Wenlei Guo ◽  
Lele Zhang ◽  
Lu’an Ge ◽  
...  
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Control Strategies ◽  
Abiotic Factors ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Burial Depth ◽  
Effective Measure ◽  
Wide Range

Shortawn foxtail is an invasive grass weed infesting winter wheat and canola production in China. A better understanding of the germination ecology of shortawn foxtail would help to develop better control strategies for this weed. Experiments were conducted under laboratory conditions to evaluate the effects of various abiotic factors, including temperature, light, pH, osmotic stress, salt concentration, and planting depth, on seed germination and seedling emergence of shortawn foxtail. The results showed that the seed germination rate was greater than 90% over a wide range of constant (5 to 25C) and alternating (15/5 to 35/25C) temperatures. Maximum germination occurred at 20C or 25/15C, and no germination occurred at 35C. Light did not appear to have any effect on seed germination. Shortawn foxtail germination was 27% to 99% over a pH range of 4 to 10, and higher germination was obtained at alkaline pH values ranging from 7 to 10. Seed germination was sensitive to osmotic potential and completely inhibited at an osmotic potential of −0.6 MPa, but it was tolerant to salinity: germination even occurred at 200 mM NaCl (5%). Seedling emergence was highest (98%) when seeds were placed on the soil surface but declined with the increasing burial depth. No seedlings emerged when seeds were buried 6-cm deep. Deep tillage could be an effective measure to limit seed germination from increased burial depth. The results of this study will lead to a better understanding of the requirements for shortawn foxtail germination and emergence and will provide information that could contribute to its control.

Seed Germination Ecology of Itchgrass (Rottboellia cochinchinensis)

Weed Science ◽  
2011 ◽  
Vol 59 (2) ◽  
pp. 182-187 ◽  
Author(s):  
Grace E-K. Bolfrey-Arku ◽  
Bhagirath S. Chauhan ◽  
David E. Johnson
Keyword(s):  
High Temperature ◽  
Seed Germination ◽  
Seedling Emergence ◽  
Soil Surface ◽  
The Philippines ◽  
Integrated Weed Management ◽  
Burial Depth ◽  
Soil Burial ◽  
Dark Regime ◽  
Temperature Pretreatment

Itchgrass is a weed of many crops throughout the tropics and one of the most important grass weeds of rainfed rice. Experiments were conducted in the laboratory and screenhouse to determine the effects of light, alternating day/night temperatures, high temperature pretreatment, water stress, seed burial depth, and rice residue on seed germination and seedling emergence of itchgrass in the Philippines. Two populations were evaluated and the results were consistent for both populations. Germination in the light/dark regime was greater at alternating day/night temperatures of 25/15 C than at 35/25, 30/20, or 20/10 C. Light was not a requirement for germination, but a light/dark regime increased germination by 96%, across temperature and population. A 5-min high temperature pretreatment for 50% inhibition of maximum itchgrass germination ranged from 145 to 151 C with no germination when seeds were exposed to ≥ 180 C. The osmotic potential required for 50% inhibition of maximum germination was −0.6 MPa for itchgrass, although some seeds germinated at −0.8 MPa. Seedling emergence was greatest for seeds placed on the soil surface, and emergence declined with increasing soil burial depth; no seedlings emerged from seeds buried at 10 cm. The addition of rice residue to soil surface in pots at rates equivalent to 4 to 6 Mg ha−1reduced itchgrass seedling emergence. Since seedling emergence was greatest at shallow depths and germination was stimulated by light, itchgrass may become a problem in systems where soil is cultivated at shallow depths. Knowledge gained in this study could contribute to developing components of integrated weed management strategies for itchgrass.

scholarly journals Paper-based inoculum of Bacillus megaterium and its practical application for simple culture preparation

2019 ◽  
Vol 72 ◽  
pp. 195-204
Author(s):  
Mana Kanjanamaneesathian ◽  
Wasunan Nimanong
Keyword(s):  
Seed Germination ◽  
Bacillus Megaterium ◽  
Large Scale ◽  
Bacterial Culture ◽  
Culture Technique ◽  
Damping Off ◽  
Bacterial Endospores ◽  
Yardlong Bean ◽  
Bacterium Bacillus ◽  
Filter Papers

The bacterium Bacillus megaterium can be used to biologically control sheath blight and grain discoloration in rice. Large-scale inoculations using liquid cultures are cumbersome so the efficacy of an alternative, paper-based system was examined. Bacterial endospores were embedded on filter papers and multiplied using a simple culture technique. The resulting suspension was used to pre-soak yardlong bean and cucumber seeds before sowing to assess its effect on seed germination and weight. The efficacy of the bacterium in protecting cucumber seeds from pre-emergent damping-off was also examined. The population of bacteria embedded in paper declined initially but remained stable for 150 days at room temperature. Bacterial culture reduced seed germination of cucumber and seedling weight of yardlong beans. Dilution with water either increased or reduced germination of cucumber seeds depending on concentration. A 1:10 v/v dilution increased cucumber-seed germination in a pre-emergent damping-off pot test but all seedlings later died, irrespective of treatment. Paper-based inoculum has the potential to replace liquid inoculum but further work is required to optimise the concentrations of the bacterial culture to achieve disease control without adversely affecting the host plant.

scholarly journals Impact of Environmental Factors on Seed Germination and Seedling Emergence of White Clover (Trifolium repens L.)

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 190
Author(s):  
Lei Chu ◽  
Yiping Gao ◽  
Lingling Chen ◽  
Patrick E. McCullough ◽  
David Jespersen ◽  
...  
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
White Clover ◽  
Trifolium Repens ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Soil Surface ◽  
High Sensitivity ◽  
Series Of Experiments ◽  
Trifolium Repens L

White clover (Trifolium repens L.) is cultivated as a forage crop and planted in various landscapes for soil conservation. There are numerous reports of failed white clover stands each year. A good understanding of the seed germination biology of white clover in relation to environmental factors is essential to achieve successful stand establishment. A series of experiments were conducted to investigate the impacts of light, temperature, planting depth, drought, and salt stress on seed germination and the emergence of white clover. White clover is negatively photoblastic, and seed germination averaged 63 and 66% under light and complete dark conditions 4 weeks after planting (WAP), respectively. Temperature affected the seed germination speed and rate. At 1 WAP, seeds incubated at 15 to 25 °C demonstrated a significantly higher germination rate than the low temperatures at 5 and 10 °C; however, the germination rate did not differ among the temperature treatments at 4 WAP. The results suggest that white clover germination decreases with increasing sowing depths, and the seeds should be sown on the soil surface or shallowly buried at a depth ≤1 cm to achieve an optimal emergence. White clover seeds exhibited high sensitivity to drought and salinity stress. The osmotic potential and NaCl concentration required to inhibit 50% seed germination were −0.19 MPa and 62.4 mM, respectively. Overall, these findings provide quantifiable explanations for inconsistent establishment observed in field conditions. The results obtained in this research can be used to develop effective planting strategies and support the successful establishment of white clover stands.

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