Effects of mulching and insecticides on establishment and growth of Norway spruce

2006 ◽  
Vol 36 (10) ◽  
pp. 2377-2385 ◽  
Author(s):  
Karin Johansson ◽  
Göran Örlander ◽  
Urban Nilsson

Establishment of Norway spruce (Picea abies (L.) Karst.) seedlings is often restricted by competition from vegetation, drought, and damage by pine weevils. In this study, effects of mulching on these factors were investigated. Norway spruce seedlings were planted on fresh and 1-year-old clearcuts treated with mulch on three sites in southern Sweden. Mulch was made of slash from the old stand and applied on whole blocks at three different depths: 0, 10, and 20 cm. Both insecticide-treated and untreated seedlings were planted. By reducing the competing vegetation and improving soil moisture and mineralization, mulching created a favorable growth environment. Mulching significantly improved growth in terms of height, diameter, and volume of the seedlings. Growth continued to increase over time in mulched treatments, probably as an effect of increased nutrient availability. The 20 cm mulch layer generated the greatest increase in growth throughout the 10-year experimental period. Soil moisture was preserved under the isolating mulch layer and during periods of drought soil water potential was significantly higher in mulched treatments. After 2 years, percent cover of competing vegetation was 50%–60% without mulch and 10%–20% with a mulch depth of 20 cm. Insecticide-treated seedlings achieved a survival rate close to 100% in all mulching treatments, whereas survival among untreated seedlings was only 40% on some clearcuts. Mulching alone did not affect survival or abundance of pine weevils.

1995 ◽  
Vol 25 (5) ◽  
pp. 790-802 ◽  
Author(s):  
Urban Nilsson ◽  
Göran Örlander

A field experiment was established between 1989 and 1993 to study the effects of (i) the age of clearcuts on damage by pine weevils (Hylobiusabietis L.) and (11) competing vegetation on the survival and growth of planted Norway spruce (Piceaabies (L.) Karst.). On each of four sites Norway spruce seedlings were planted on 0 to 4-year-old clearcuts. Effects of mounding, herbicide and mowing, removal of slash, and seedling stock type were also investigated. As many seedlings suffered severely from a drought that affected southern Sweden in 1992, this study reports a separate analysis of mortality due to drough. From the middle of May until the beginning of July 1992, only negligible precipitation was recorded on all four sites. The biomass of ground vegetation was correlated with the age of the clearcut. On fresh and 1-year-old clearcuts, only negligible amounts of vegetation were found, whereas about 2 Mg•ha−1 of ground vegetation were found on 2- and 3-year-old clearcuts. Low soil water potentials were recorded on 2- and 3-year-old clearcuts but not on fresh clearcuts. There was no effect of the slash removal treatment on soil water potential, but there was a significant effect of the soil and vegetation treatments. Mounding and herbicide treatments increased the soil water potentials compared with untreated controls and mowed plots. Mortality by drought was higher for seedlings planted on old clearcuts than for seedlings planted on fresh ones. Mortality was reduced by mounding, but late planting increased the number of dead seedlings significantly. The mortality of containerized seedlings was considerably less than that of bare-root seedlings. On old clearcuts growth of seedlings planted on plots with no vegetation control (untreated control and mown plots) was less than that of seedlings planted on plots where transpiration by ground vegetation was reduced (herbicide and mounding).


2019 ◽  
Vol 65 (No. 2) ◽  
pp. 51-60 ◽  
Author(s):  
Vít Šrámek ◽  
Kateřina Neudertová Hellebrandová ◽  
Věra Fadrhonsová

Interception, soil moisture and soil water potential were observed in four Norway spruce stands of different age in two subsequent vegetation seasons 2017 and 2018. Vegetation season 2018 can be characterized as being abnormally hot and dry with only 66% of precipitation in comparison with normal conditions. The interception of spruce increased with the stand age and its dimensions, ranging between 16 and 48% in 2017 and in the majority of stands even increasing in 2018. The soil moisture significantly decreased during the vegetation season 2018, with soil water potential close to the permanent wilting point (–1.5 MPa) for a substantial part of the monitored period. Differences between individual stands were observed in terms of the soil water potential (SWP) development which does not follow the interception patterns suggesting that the stand transpiration is a driving factor responsible for the soil water budget. In all stands, with the exception of the oldest one, the SWP of the upper soil horizon was less than 1.5 MPa for more than 80 days. In such extreme conditions the drought would negatively influence any Norway spruce stand regardless of its age or structure.


2006 ◽  
Vol 36 (10) ◽  
pp. 2400-2411 ◽  
Author(s):  
Paula Jylhä ◽  
Jyrki Hytönen

The effects of competing vegetation and various weed control methods (fibreboard mulch, cover crop of clover, and various herbicides) on the survival and growth of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings were compared based on 6- to 11-year data from a field experiment established as a randomized block design with three replications in southern Finland. The most effective herbicides significantly reduced the weed cover for 2 or 3 years. The mortality, basal diameter, height, and volume of Scots pine significantly correlated with percent cover of the ground vegetation. In the case of Norway spruce, only the stem diameter correlated significantly with percent cover of the competing vegetation. This was probably due to the severe frost damage that occurred in the third growing season. The mortality of pine began to increase only when the vegetation cover had exceeded 60%. After 11 years, the stand volume on the pine plots treated with terbuthylazine was almost double that of the untreated plots (32 vs. 17 m3·ha–1), but this difference was not statistically significant. Mulch and cover crop did not significantly affect pine growth or mortality. Recurrent frost damage may explain why none of the studied treatments significantly affected the mortality and volume growth of Norway spruce.


1999 ◽  
Vol 29 (7) ◽  
pp. 1015-1026 ◽  
Author(s):  
Urban Nilsson ◽  
Göran Örlander

A field experiment was established between 1989 and 1993 to study the effects of competing vegetation on growth of planted Norway spruce (Picea abies (L.) Karst.) seedlings. Effects of clearcut age, scarification (mounding), herbicide treatment, and seedling stock type were investigated 5 years after planting. On fresh clearcuts, amounts of vegetation were negligible, whereas 2.1-3.7 Mg·ha-1 was found on 4-year-old and older clearcuts. Soil temperatures were about 10% higher in mounds than in undisturbed ground, while herbicide and clearcut age only marginally affected soil temperatures. Seedlings planted on old clearcuts showed significant reductions in growth due to interference from vegetation. Five years after planting, the reduction in growth corresponded to about 1 year's growth. Most of the interaction between seedlings and vegetation occurred during the first 2 years after planting. Thus, scarification was just as effective as repeated herbicide treatments in reducing competition from vegetation. Differences in periods of drought between years could largely explain variation in leading shoot length. However, leading shoot length was affected in the same way irrespective of vegetation control treatments. Five years after planting, the relative differences in diameter between bare-root and containerized seedlings were the same as at the time of planting.


1982 ◽  
Vol 60 (12) ◽  
pp. 2518-2529 ◽  
Author(s):  
Christopher Walker ◽  
Carl W. Mize ◽  
Harold S. McNabb Jr.

Two different sites in central Iowa were planted with hybrid poplars and subsequently sampled over a growing season for spores of endogonaceous fungi. At one of the sites, the effects of plowing and herbicide treatment on spore numbers also were examined. Ten species of fungi in the genera Acaulospora, Gigaspora, and Glomus were recorded at the first site. The second location yielded 12 species from the same genera. In both sites, the distribution of spores was highly variable. The poplars rarely became endomycorrhizal and had no effect on spore populations during the experimental period. Changes in spore populations were correlated with soil-moisture level. Evidence was found for some depression of spore production caused by plowing and herbicide treatment. The conclusion was drawn that small samples with but few replicates may not adequately represent populations of endogonaceous spores.


2021 ◽  
Author(s):  
Nunziarita Palazzolo ◽  
David J. Peres ◽  
Enrico Creaco ◽  
Antonino Cancelliere

<p>Landslide triggering thresholds provide the rainfall conditions that are likely to trigger landslides, therefore their derivation is key for prediction purposes. Different variables can be considered for the identification of thresholds, which commonly are in the form of a power-law relationship linking rainfall event duration and intensity or cumulated event rainfall. The assessment of such rainfall thresholds generally neglects initial soil moisture conditions at each rainfall event, which are indeed a predisposing factor that can be crucial for the proper definition of the triggering scenario. Thus, more studies are needed to understand whether and the extent to which the integration of the initial soil moisture conditions with rainfall thresholds could improve the conventional precipitation-based approach. Although soil moisture data availability has hindered such type of studies, yet now this information is increasingly becoming available at the large scale, for instance as an output of meteorological reanalysis initiatives. In particular, in this study, we focus on the use of the ERA5-Land reanalysis soil moisture dataset. Climate reanalysis combines past observations with models in order to generate consistent time series and the ERA5-Land data actually provides the volume of water in soil layer at different depths and at global scale. Era5-Land project is, indeed, a global dataset at 9 km horizontal resolution in which atmospheric data are at an hourly scale from 1981 to present. Volumetric soil water data are available at four depths ranging from the surface level to 289 cm, namely 0-7 cm, 7-28 cm, 28-100 cm, and 100-289 cm. After collecting the rainfall and soil moisture data at the desired spatio-temporal resolution, together with the target data discriminating landslide and no-landslide events, we develop automatic triggering/non-triggering classifiers and test their performances via confusion matrix statistics. In particular, we compare the performances associated with the following set of precursors: a) event rainfall duration and depth (traditional approach), b) initial soil moisture at several soil depths, and c) event rainfall duration and depth and initial soil moisture at different depths. The approach is applied to the Oltrepò Pavese region (northern Italy), for which the historical observed landslides have been provided by the IFFI project (Italian landslides inventory). Results show that soil moisture may allow an improvement in the performances of the classifier, but that the quality of the landslide inventory is crucial.</p>


2015 ◽  
Vol 12 (1) ◽  
pp. 177-191 ◽  
Author(s):  
C. Wu ◽  
I. Pullinen ◽  
S. Andres ◽  
G. Carriero ◽  
S. Fares ◽  
...  

Abstract. Impacts of soil moisture on de novo monoterpene (MT) emissions from Holm oak, European beech, Scots pine, and Norway spruce were studied in laboratory experiments. The volumetric water content of the soil, Θ, was used as the reference quantity to parameterize the dependency of MT emissions on soil moisture and to characterize the severity of the drought. When Θ dropped from 0.4 m3 × m−3 to ~0.2 m3 × m−3 slight increases of de novo MT emissions were observed but with further progressing drought the emissions decreased to almost zero. In most cases the increases of MT emissions observed under conditions of mild drought were explainable by increases of leaf temperature due to lowered transpirational cooling. When Θ fell below certain thresholds, MT emissions decreased simultaneously with Θ and the relationship between Θ and MT emissions was approximately linear. The thresholds of Θ (0.044–0.19 m3 × m−3) were determined, as well as other parameters required to describe the soil moisture dependence of de novo MT emissions for application in the Model of Emissions of Gases and Aerosols from Nature, MEGAN. A factorial approach was found appropriate to describe the impacts of Θ, temperature, and light. Temperature and Θ influenced the emissions largely independently from each other, and, in a similar manner, light intensity and Θ acted independently on de novo MT emissions. The use of Θ as the reference quantity in a factorial approach was tenable in predicting constitutive de novo MT emissions when Θ changed on a time scale of days. Empirical parameterization with Θ as a reference was only unsuccessful when soil moisture changed rapidly


Author(s):  
Ortega-Corral César ◽  
B. Ricardo Eaton-González ◽  
Florencio López Cruz ◽  
Laura Rocío, Díaz-Santana Rocha

We present a wireless system applied to precision agriculture, made up of sensor nodes that measure soil moisture at different depths, applied to vine crops where drip irrigation is applied. The intention is to prepare a system for scaling, and to create a Wireless Sensor Network (WSN) that communicates by radio frequency with a base station (ET), so that the gathered data is stored locally and can be sent out an Internet gateway.


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