Soil Water Levels Research Articles

Regulating Vapor Pressure Deficit and Soil Moisture Improves Tomato and Cucumber Plant Growth and Water Productivity in the Greenhouse

Atmospheric vapor pressure deficit (VPD) is the driving force that regulates the rate of water transport within plants. Under High VPD (HVPD), plants always reduce their photosynthesis rate and close their stomata. Experiments were performed under greenhouse conditions with cucumber and tomato plants to identify the regulatory effect of VPD on plant water capacity. Treatments included two levels of soil water (100% and 60% field capacity [FC]) combined with two levels of VPD (LVPD and HVPD). Results indicated that with 60%FC, the plant heights of tomato and cucumber were enhanced under LVPD compared with those under HVPD. With 60%FC, relative leaf water contents under LVPD increased by 11% compared with those under HVPD. Furthermore, LVPD significantly improved the photosynthetic capacity of the two crops and changed their stress responses. Our results indicated that LVPD at different soil moisture levels reduced irrigation demand under greenhouse conditions. This approach can be applied in water management in greenhouse vegetable production in China and other regions of the world with temperate continental climates.

Physiological and metabolic alterations in basil (Ocimum basilicum L.) varieties under distinct soil water levels

Basil (Ocimum basilicum L.) is a medicinal species used in several areas, such as food, medicines and cosmetics, and the understanding of its physiological behavior under environmental conditions is of paramount importance for the improvement of cultivation methods. The objective of this study was to evaluate the influence of different water availability under physiological, biochemical and metabolic characteristics, in three distinct genotypes: 'Alfavaca basilicão', 'Gennaro de menta' and 'Grecco à palla', during two different phenological stages (vegetative and reproductive). It was found that the water deficit promotes physiological changes to tolerate water stress, and the studied genotypes have different routes to achieve this physiological tolerance, which culminates in a distinct accumulation of metabolites in plants, and can be considered interesting if the final product is the production of essential oils.

Assessing soil water recovery after converting planted shrubs and grass to natural grass in the northern Loess Plateau of China

The Chinese Loess Plateau (CLP) is prone to adverse effects from drought, especially the widespread creation of a dried soil layer (DSL), a problem intensified by revegetation under the Grain for Green Program. Using 13-year soil moisture (SM) data, we compared soil water consumption by planted shrubs (Korshinsk peashrub, KOP), planted grass (purple alfalfa, ALF), and natural grass (NAG) from 2004 to 2016 in the CLP. To assess the soil water recovery processes, long-term (30 years) SM dynamics were simulated using the simultaneous heat and water (SHAW) model based on field data and local meteorological data under two scenarios (A: converting KOP to NAG and B: converting ALF to NAG). The results showed that the decline rates of SM in 1–4 m profiles for NAG (24.0–29.8%) were much lower than those for KOP (47.6–51.4%) and ALF (48.8–50.2%) during the 13-year growth period. Modelling SM dynamics at depths of 1–4 m for 30 years showed that SM gradually increased and that the DSL prevalence could be reduced under scenarios A and B. The complete elimination of DSL requires at least 6 years at 1–4 m under scenario A, 13 years at 2–4 m, and 22 years at 1–2 m under scenario B. Soil water restored to local stable soil water levels requires approximately 19, 13, and 15 years in the 1–2 m, 2–3 m, and 3–4 m profiles, respectively, under scenario A. Soil water recovery will take approximately 28 years in the 2–3 m profile and 27 years in the 3–4 m profile under scenario B. Our results enhance the understanding of the soil water depletion and recovery processes under different vegetation types and can could be used to provide scientific guidance for sustainable ecological restoration in the CLP.

Mycorrhiza improves plant growth and photosynthetic characteristics of tea plants in response to drought stress

Tea plants are sensitive to soil moisture deficit, with the level of soil water being a critical factor affecting their growth and quality. Arbuscular mycorrhizal fungi (AMF) can improve water and nutrient absorption, but it is not clear whether AMF can improve the photosynthetic characteristics of tea plants. A potted study was conducted to determine the effects of Claroideoglomus etunicatum on plant growth, leaf water status, pigment content, gas exchange, and chlorophyll fluorescence parameters in Camellia sinensis cv. Fuding Dabaicha under well-watered (WW) and drought stress (DS) conditions. Root mycorrhizal colonization and soil hyphal length were significantly reduced by the eight-week DS treatment. AMF inoculation displayed a significant increase in shoot and root biomass production. The relative water content, leaf water potential, nitrogen balance index, pigment content, maximum photometric effect (Fv/Fm, QY_max), and steady-state photometric effect Y (II) (QY_Lss) decreased dramatically, while the leaf water saturation deficit and steady-state non-photochemical fluorescence quenching (NPQ_Lss) generally increased under DS conditions. Mycorrhizal treatment induced significantly higher relative water content, leaf water potential, nitrogen balance index, pigment (chlorophyll, flavonoid, and anthocyanin) content, net photosynthesis rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, QY_max, and QY_Lss; however, it resulted in a lower leaf water saturation deficit and NPQ_Lss under both WW and DS conditions, as compared with non-mycorrhizal plants. These results imply that AMF promoted tea plant growth and alleviated negative effects of DS by promoting gas exchange, regulating the water status of leaves, and regulating photosynthetic parameters.

Design of solar powered smart water pump for moisture controller in agriculture sector

The article discusses the design, which includes monitoring the moisture of the soil as well as the level of water in the tank, as well as turning on and off the pump motor based on the soil moisture content. An ultrasonic sensor for cattle detection and an LDR sensor for automatic lighting of agriculture has used. An application is designed such that the user can view the water level as well as the moisture content and can control the motor directly from the application. Single axis solar tracker is used for efficient power supply to the water pump. The benefit of this technology is that it requires less human interaction while yet ensuring proper irrigation. The ARDUINO UNO series controller is used, which is conditioned to receive input signals of varying soil moisture conditions and water levels via sensing. When the microcontroller receives a signal, it produces an output that controls the water pump through a relay. The ultrasonic sensor sends input signal to the microcontroller whenever a disturbance is detected in its range and the microcontroller generates signal to the buzzer to turn on. NODEMCU is used as interconnection between the microcontroller and application. NODEMCU uses Wi-Fi to transmit the data to the mobile application and can receive signal from the mobile application. The status of the soil and water quantity is also displayed on an LCD monitor. The proposed system is implemented in prototype model and analysed for different conditions and obtained results are tabulated for validation.

IoT Based Smart Agriculture Monitoring, Weather Control and Irrigation System

Agriculture plays vital role in the development of agricultural country like India. In India about 70% of population depends upon farming. Agriculture is done manually from ages. As the world is trending into new technologies and implementations it is a necessary goal to trend up with Agriculture also. due to migration of people from rural to urban there are difficulties in agriculture. In day today life, technology is updating and it is also necessary to trend up agriculture too. IoT can play a key role in smart agriculture. Hence the paper aims at making agriculture smart using automation and IoT technologies. IOT based Agriculture monitoring system makes use of wireless sensor networks that collects data from different sensors deployed at various nodes and sends it through the wireless protocols. It includes the humidity sensor, temperature sensor, soil moisture sensor and water level sensor. The features of this project include an android application which shows the live information about the temperature, humidity, soil moisture, water level. Secondly it includes smart irrigation with smart control and intelligent decision making based on accurate real time field data. Thirdly an automatic weather control system which controls the humidity and temperature of the field (e.g. green house).

Potential Study of Liquefaction in the Downstream Area of Jono Oge-Paneki River, Central Sulawesi

Liquefaction during an earthquake is likely to occur in the quaternary geological layer of sediment. Based on the geological process, the mainland of Central Sulawesi was initially a sea lifted upward to become land Palu-Koro fault. Therefore, the land is basically of basic alluvium soil formation, sand deposits, and loose rock. The earthquake in Central Sulawesi in September 2018 was the cause of liquefaction, one of which was in the Jono Oge area, where most of the flow entered the Paneki river. This paper analyzed the potential for recurrent liquefaction by considering the soil structure and water level conditions. The authors focused on the downstream areas of the Paneki River, which passes through Langaleso and Kabobona Village. The data used is N-SPT data, followed by examining post-liquefaction settlement and lateral displacement. This study uses several variations of the earthquake magnitude and potential earthquakes that may occur. The results of observations indicate that the soil conditions of the study area are cohesionless soil. The liquefaction analysis shows that most of the research areas have liquefaction, land subsidence, and lateral displacement potential.

The plasticity of early root development in Sesamum indicum L. as influenced by genotype, water, and nutrient availability

Precise knowledge on the impact of varying soil moisture and nutrient levels on the root system architecture of sesame is lacking. To that end, four non-dehiscent sesame cultivars (Sesaco32, 35, 38 and 40) were grown in rhizoboxes under four different soil water levels (60, 80, 100 and 120% of soil water holding capacity) over four replications. Two identical runs were performed without added nutrients and two other runs with added nutrients. The rhizoboxes were scanned at 2, 4, 7, 9, 11, 13, 14, 16, 18, and 21 days after planting (DAP) without nutrients, and only until 16 DAP with added nutrients. Images were analyzed for total root length (TRL) and average length per individual root branch (ARL). Results showed that without nutrients, TRL reached a plateau at 50.5 cm at 18 DAP on average across treatments, and S35 had the highest (66.4 cm) and S40 the lowest (31.4 cm) TRL at 21 DAP. TRL was only marginally affected by soil water level without nutrients. With added nutrients, TRL showed an exponential growth pattern reaching 103 cm at 16 DAP on average across treatments and was not affected by cultivar nor soil water level. These results showed that reduced soil water level has little to no impact on TRL, but that genotypic differences play an important role in determining belowground development without nutrients. A visual representation of root spatial distribution showed that although TRL differences existed between cultivar without nutrients, root spatial exploration appeared consistent. With added nutrients, the lack of significant difference in TRL between 100 and 120% soil water level (100.2 ± 19.2 and 114.1 ± 19.7 cm respectively) was not consistent with root spatial exploration, as these two soil water treatments displayed different RSA. These results show that sesame's early rooting behavior is controlled closely by genotypic factors in nutrient poor conditions, and that soil fertility can have a strong positive impact on early root growth. This is of interest to sesame breeders who could use nutrient poor environments to select for root architecture traits and improve the drought tolerance of the crop.

Integrated Duflow-Drainmod model for planning of water management operation in tidal lowland reclamation areas

The research objective was to develop field operational model to control water table level at reclaimed area of tidal lowland for food crop cultivation. DUFLOW computer model was used to evaluate the perfomance of water management network at secondary and tertiary levels, whereas DRAINMOD computer model is used to evaluate soil water status at tertiary block. Results of DUFLOW model simulation can be used to improve water management by passing the Secondary Irrigation Chanel (SPD) and Secondary Drainage Chanel (SDU) through tertiary channels, water gate installation of stop-log type and weir construction in Drainage Secondary Channel (SDU). The weir construction has function as long storage and capable to control or maintain soil water level in land not quickly drawdown. Drainmod simulation model is acceptable, this is indicated by the results of statistical analysis where the correlation coefficient value reaches 0.89. Analysis of DUFLOW-DRAINMOD computer model software showed mutually supportive results in which DUFLOW simulation results can provide water potential information in channel for supply purpose. This water level condition is an important part in DRAINMOD model because it has effect on soil water level dynamics as targeted on tertiary block as well as on capacity to applied drainage operation system.

Nitrogen source effects on canola (Brassica napus L.) grown under conservation agriculture in South Africa

AbstractCanola (Brassicanapus L.) growth and yield can be enhanced by, amongst others, choosing the correct rate, source, and timing of N fertilizer. Limited research exists on the effects of nitrogen (N) source on canola growth and yield properties when grown under conservation agriculture. This study compared the performance of different N fertilizer sources on canola biomass production, seed yield, and oil content. Field trials were conducted from 2016 to 2019 at five sites in the Western Cape Province of South Africa which is characterized by a Mediterranean climate. Nitrogen fertilizer source had no effect (p > .05) on biomass production or oil content at any site. Sufficient soil water levels and warm daily temperatures led to greater biomass production regardless of nitrogen source. Oil content was determined by the presence of rainfall during the flowering and seed filling stages. The effect of N source on yield varied among sites in accordance with timing of fertilizer application in relation to rainfall. The urea + urease inhibitor N source led to greater (p < .05) yields than the urea N source without the inhibitor at the Darling site, regardless of the soil water conditions. Mean yield values of all seasons and sites indicated that urea + urease inhibitor fertilizer to be the most reliable N source to ensure optimal yields over the long‐term.

Reduction of Greenhouse Gases from Peat Soils in Dutch Agriculture

SummaryPeat soils that are drained to enable productive agriculture result in land subsidence and greenhouse gas (GHG) emissions. These have negative effects on the environment, in particular climate change, and rural infrastructure. This article reviews the EU and Dutch regulatory requirements for reducing GHG emissions and discusses options to reduce the negative effects of peat soils. An optimisation farm model based on Dutch farm data provides estimates of farm income losses for three different changes in water levels in peat soils associated with changes in production methods for three options of NH3 emission reductions and three options for nature conservation areas. Model results suggest that carbon credits are an excellent method of financing the costs that farmers face when adapting to legal requirements for lower emissions, ideally raising water levels to –20 cm below field level. The comparison of scenario results also outlines the need to take account of different policy objectives simultaneously in policy evaluation, as do farmers when they adapt their farm practices to the policy environment. Opportunities to add value from markets could also help reduce the income loss from the adoption of more environmentally‐friendly practices.

IPOTs: Internet of Things-based pot system controlling optional treatment of soil water condition for plant phenotyping under drought stress.

A cultivation facility that can assist users in controlling the soil water condition is needed for accurately phenotyping plants under drought stress in an artificial environment. Here we report the Internet of Things-based pot system controlling optional treatment of soil water condition (iPOTs), an automatic irrigation system that mimics the drought condition in a growth chamber. The Wi-Fi-enabled iPOTs system allows water supply from the bottom of the pot, based on the soil water level set by the user, and automatically controls the soil water level at a desired depth. The iPOTs also allows users to monitor environmental parameters, such as soil temperature, air temperature, humidity, and light intensity, in each pot. To verify whether the iPOTs mimics the drought condition, we conducted a drought stress test on rice (Oryza sativa L.) varieties and near-isogenic lines, with diverse root system architecture, using the iPOTs system installed in a growth chamber. Similar to the results of a previous drought stress field trial, the growth of shallow-rooted rice accessions was severely affected by drought stress compared with that of deep-rooted accessions. The microclimate data obtained using the iPOTs system increased the accuracy of plant growth evaluation. Transcriptome analysis revealed that pot positions in the growth chamber had little impact on plant growth. Together, these results suggest that the iPOTs system is a reliable platform for phenotyping plants under drought stress.

Soil properties and infiltration rate in sago palm (Metroxylon sago) forest in Rongkong Watershed South Sulawesi

Sago palm, one of the dominant wetland vegetation in the Rongkong Watershed, contributes to groundwater recharge through its ability to pass water into the ground. This study aims to determine the effect of sago forest canopy density on the infiltration rate in the middle and downstream zones of the Rongkong Watershed in South Sulawesi. Other independent variables were soil texture, permeability, bulk density, porosity, soil organic matter, initial soil moisture, water level, air temperature, and air humidity. The relationship between the independent variables on the infiltration rate was analyzed using multiple linear regression. Infiltration rate observes with ponded infiltration method at five density classes of sago forest. The results showed that the infiltration rate in the middle stream increased along with the increase of density classes of sago forests. The downstream, on the other hand, has an insignificant difference between density classes. The result of the regression analysis showed that the coefficient of determination in the middle and downstream zones was 64.5 % and 38.5 %, respectively. The simultaneous test of variable significance in the middle stream shows that the sago forest canopy density, groundwater level, initial soil moisture, and air humidity significantly affect a p-value <0.05.

Decreasing Defoliation Frequency Enhances Bromus valdivianus Phil. Growth under Low Soil Water Levels and Interspecific Competition

Bromus valdivianus Phil. (Bv) is a water stress-tolerant species, but its competitiveness in a diverse pasture may depend on defoliation management and soil moisture levels. This glasshouse study examined the effect of three defoliation frequencies, based on accumulated growing degree days (AGDD) (250, 500, and 1000 AGDD), and two soil water levels (80–85% of field capacity (FC) and 20–25% FC) on Bv growth as monoculture and as a mixture with Lolium perenne L. (Lp). The treatments were applied in a completely randomised block design with four blocks. The above-ground biomass of Bv was lower in the mixture than in the monoculture (p ≤ 0.001). The Bv plants in the mixture defoliated more infrequently (1000 AGDD) showed an increase in root biomass under 20–25% FC compared to 80–85% FC, with no differences measured between soil water levels in the monoculture. Total root length was highest in the mixture with the combination of infrequent defoliation and 20–25% FC. Conversely, frequent defoliation treatments resulted in reduced water-soluble carbohydrate reserves in the tiller bases of plants (p ≤ 0.001), as they allocated assimilates mainly to foliage growth. These results provide evidence that B. valdivianus can increase its competitiveness relative to Lp through the enhancement of the root growth and the energy reserve in the tiller base under drought conditions and infrequent defoliation in a mixture.

Design a Monitoring and Control in Irrigation Systems using Arduino Wemos with the Internet of Things

Irrigation door is a big issue for farmers. The factor that became a hot issue at the irrigation gate was the irresponsible attitude of the irrigation staff regarding the schedule of opening/closing the irrigation door so that it caused the rice fields to becoming dry or submerged. In this research, an automatic prototype system for irrigation system will be designed based on integrating several sensors, including water level sensors, soil moisture sensors, acidity sensors. This sensor output will be displayed on Android-based applications. The integration of communication between devices (Arduino Nano, Arduino Wemos and sensors supporting the irrigation system) is the working principle of this prototype. This device will control via an Android-based application to turn on / off the water pump, to open/close the irrigation door, check soil moisture, soil acidity in real time. The pump will automatically turn on based on the water level. This condition will be active if the water level is below 3cm above ground level. The output value will be displayed on the Android-based application screen and LCD screen. Based on the results of testing and analysis of the prototype that has been done in this research, the irrigation door will open automatically when the soil is dry. This condition occurs if the water level is less than 3 cm. The calibrated Output value, including acidity sensor, soil moisture sensor and water level sensor, will be sent to the server every 5 seconds and forwarded to an Android-based application as an output display.

Properties and sustainable management of the inland wetland soils for efficient rice production in Southern Guinea Savanna zone of Nigeria

ABSTRACT A pedological study was carried out on some inland wetland soils of Obukiyo, Oju Local Government Area of Benue State, Nigeria to identify their properties and suggest sustainable management practices for the soils. The grid method of soil survey was employed in the field to investigate the morphological and physicochemical properties of the soils. Four soil units were identified on the field based on soil colour, texture, structure, surface properties, topography and water level. Two pits were sunk in each soil unit, described and sampled for laboratory analysis. The soil units were deep (160cm to 190cm) and somewhat well to very poorly drained. The soils were fine texture and slightly to moderately acid and slightly alkaline in reaction (pH 4.1-7.8). The percentage sand fraction ranged between 35.12% and 79.75%, silt, 0.00% and 36.56% and clay 19.76% and 58.46%. They had low to moderate organic carbon (0.30%-2.25%), total N (0.01%-0.42%) available P (213 mg/kg-6.515mgkg-1), total exchangeable bases (3.61cmolkg– 8.26cmolkg), E.A (0.62cmolkg-1 – 3.63cmolkg-1) CEC (3.75cmolkg-1 8.34cmolkg-1), ECEC (5.70cmolkg-1-10.33cmolkg-1) and high base saturation of 53% to 93%. Based on the physicochemical properties, management practices such as; minimal tillage, application of organic and inorganic fertilizers, application of lime to reduce acidity in unit 1 and integrated planting time management with water control were recommended for units II, III and IV.

Smart E-Farming

Agriculture plays vital role within the development of agricultural country. In India about 70% of population depends upon farming and one third of the nation’s capital comes from farming. Issues concerning agriculture are always hindering the event of the country. The only solution the present to the present problem is sensible agriculture by modernizing the current traditional methods of agriculture. Hence the project aims at making agriculture smart using automation and IoT technologies. The concept smart-e-farming is developed for the ease in farming .It works on electrical energy. It includes number of sensors to test the soil parameters, they are as follows: Temperature Sensor. Soil moisture, Water level and Light etc. The main advantage is it has automatic operated covering which works according to water level and temperature.

SurEau: a mechanistic model of plant water relations under extreme drought

Key messageA new process-based model,SurEau, is described. It predicts the risk of xylem hydraulic failure under drought.ContextThe increase in drought intensity due to climate change will accentuate the risk of tree mortality. But very few process-based models are currently able to predict this mortality risk.AimsWe describe the operating principle of a new mechanistic model SurEau that computes the water balance, water relations, and hydraulics of a plant under extreme drought.MethodsSurEau is based on the formalization of key physiological processes of plant response to water stress. The hydraulic and hydric functioning of the plant is at the core of this model, which focuses on both water flows (i.e., hydraulic) and water pools (i.e., hydric) using variable hydraulic conductances. The model considers the elementary flow of water from the soil to the atmosphere through different plant organs that are described by their symplasmic and apoplasmic compartments. For each organ, the symplasm is described by a pressure-volume curve and the apoplasm by its vulnerability curve to cavitation. The model is evaluated on mature oak trees exposed to water stress.ResultsOn the tested oak trees, the model captures well the observed soil water balance, water relations, and level of embolism. A sensitivity analysis reveals that the level of embolism is strongly determined by air VPD and key physiological traits such as cuticular transpiration, resistance to cavitation, and leaf area.ConclusionThe process-based SurEau model offers new opportunities to evaluate how different species or genotypes will respond to future climatic conditions.

Soil type and water level treatments influence peatland CO2 efflux in simulated restoration

Peatlands are characterized by accumulation of organic matter primarily in response to soil anoxia and soil saturation. In the Cavalier Wildlife Management Area (CWMA) of southeastern Virginia, weirs were installed within ditches in an effort to restore peatlands. The purpose of this research was to determine the water levels that restore soil respiration functions and encourage carbon dioxide (CO2) sequestration. Core microcosms of two soil types (histosol and ultisol) were collected and established in the laboratory with differing water level treatments with simulated depth to water table. Incubations continued for 1 month and CO2 emission rates of the soil cores were measured twice per week using a portable photosynthesis instrument. Results from a mixed linear model and Tukey post-hoc tests demonstrated water level treatments were inversely correlated to CO2 emissions regardless of soil type and that the ultisol soil type exhibited lower percent volumetric water content and higher CO2 emissions overall. This suggests that higher water tables suppress CO2 emissions and can increase carbon sequestration, and that natural resource managers should evaluate soil types when establishing restoration and carbon sequestration goals, as soil types have differing responses to hydrologic restoration.

Legacy of bark beetles (Dendroctonus spp.) on soil carbon and nitrogen cycling seven years after forest infestation

Between years 2007 and 2013, an outbreak of pine- and spruce-bark beetles (Dendroctonus spp.) has decimated coniferous forests of the northwestern United States. Beetles introduced blue stain fungus to the tree xylem that caused blockage and discontinuation of plant water conductance. One of the immediate disease symptoms was premature and immediate drop-off of all needles rich in nitrogen (N). Soil surface-accumulated needle litter in combination with elevated soil water levels, have led to accelerated N and carbon (C) mineralization. Understanding of the soil C and N cycling during forest transition from “standing dead trees” to “snagfall and forest regrowth” is still unclear. Specifically, the potential lasting legacy of beetle-caused surface-deposited tree litter is of importance in order to assess long-term forest health. The main objective of this study was to assess whether soil C and N mineralization continues to be affected by litter chemistry in this transitional period of post beetle disturbance ecosystem recovery. Mineral soil (0–10 cm) and corresponding surface tree litter were obtained from beneath dead and live tree clusters in three forest types in Medicine Bow-Routt National Forest in Wyoming, USA. All forests were located in the same watershed, grew on similar soils, experienced up to 35% of forest mortality and consisted of: Engelmann spruce (Picea engelmannii), subalpine fir (Abies lasiocarpa) mixed with lodgepole pine (Pinus contorta), and lodgepole pine alone. Results suggest that tree litter uniformly affected mineral soils across all forest types regardless of beetle infestation. In laboratory incubations, the presence of litter doubled mineral soil heterotrophic respiration. While litter had the most uniform effect on soils, beetle infestation and forest type resulted in a number of differences. Soils beneath dead tree clusters continued to have elevated inorganic N concentrations when normalized by total N, which was twice as high compared to soils beneath live tree clusters across all forest types. The lowest NH4+ concentrations were observed in soils beneath lodgepole pine trees, which was accompanied by the highest C to N ratio of microbially available substrates. In conclusion, the legacy of forest die-offs caused by bark beetle infestation was still observable seven years later during the early transitional period. This confirms ecosystem modeling simulations that, while entering decadal stage of forest recovery, forest structure may differ depending on the forest type, and that the forest types that contain lodgepole pines may encounter an earlier onset of potential N limitation.