scholarly journals The ecological importance of moss ground cover in dry shrubland restoration within an irrigated agricultural landscape matrix

2021 ◽  
Author(s):  
Rebecca Dollery ◽  
Mike Bowie ◽  
Nicholas Dickinson
Keyword(s):  
Agricultural Landscape ◽  
Vascular Plant ◽  
Ground Cover ◽  
N Availability ◽  
Plant Interactions ◽  
Landscape Matrix ◽  
Available N ◽  
Exotic Grasses ◽  
Moss Layer ◽  
Threatened Habitat

1. Kānuka (Kunzea serotina, Myrtaceae) dryland shrubland communities of the lowland plains of South Island (Te Wai Pounamu) New Zealand (Aoteoroa) contain a ground cover largely consisting of mosses, predominantly Hypnum cupressiforme. There has been no previous study of the role of mosses in this threatened habitat which is currently being restored within a contemporary irrigated and intensively-farmed landscape that may be incompatible with this component of the ecosystem. 2. The aim of the present study was to investigate the influence of moss ground cover on hydrology, nitrogen (N) availability and vascular plant interactions, and in relation to nutrient spillover from adjacent farmland. Experimental work was a combination of glasshouse experiments and field-based studies. 3. Extremes of soil temperature and moisture were found to be mediated by the moss carpet, which also influenced N speciation; available N declined with moss depth. The moss layer decreased the amount of germination and establishment of vascular plants but, in some cases, enhanced their growth. Spillover of mineral nitrogen and phosphate from farmland enhanced invasion of exotic grasses which may have benefited from conditions provided by the moss carpet. 4. Synthesis: We found the moss layer to be crucial to ecosystem functioning in these dry habitats with low nutrient substrate. However, when the moss layer is accompanied by nutrient spillover it has the potential to increase exotic weed encroachment. Our results emphasise the importance of non-vascular plant inclusion in restoration schemes but also highlights the importance of mitigating for nutrient spillover.

Use of hot KCl-NH4-N to estimate fertilizer N requirements

1997 ◽  
Vol 77 (2) ◽  
pp. 161-166 ◽  
Author(s):  
C. A. Campbell ◽  
Y. W. Jamel ◽  
A. Jalil ◽  
J. Schoenau
Keyword(s):  
N Mineralization ◽  
Growth Models ◽  
Growing Season ◽  
Order Rate Constant ◽  
Weather Data ◽  
N Availability ◽  
Fertilizer N ◽  
Available N ◽  
Mineralizable N ◽  
Potentially Mineralizable N

We need an easy-to-use chemical index for estimating the amount of N that becomes available during the growing season, to improve N use efficiency. This paper discusses how producers may, in future, use crop growth models that incorporate indices of soil N availability, to make more accurate, risk-sensitive estimates of fertilizer N requirements. In a previous study, we developed an equation, using 42 diverse Saskatchewan soils, that related potentially mineralizable N (N0) to NH4N extracted with hot 2 M KCl (X), (i.e., N0 = 37.7 + 7.7X, r2 = 0.78). We also established that the first order rate constant (k) for N mineralization at 35°C is indeed a constant for arable prairie soils (k = 0.067 wk−1). We modified the N submodel of CERES-wheat to include k and N0 (values of N0 were derived from the hot KCl test). With long-term weather data (precipitation and temperature) as input, this model was used to estimate probable N mineralization during a growing season and yield of wheat (grown on fallow or stubble), in response to fertilizer N rates at Swift Current. The model output indicated that the amount of N mineralized in a growing season for wheat on fallow was similar to that for wheat on stubble, as we hypothesized. Further the model indicated that rate of fertilizer N had only minimal effect on N mineralized. We concluded that, despite the importance of knowing the Nmin capability of a soil, it is available water, initial levels of available N and rate of fertilizer N that are the main determinants of yield in this semiarid environment. The theoretical approach we have proposed must be validated under field conditions before it can be adopted for use. Key words: N mineralization, Hot KCl-NH4-N, potentially mineralizable N, CERES-wheat model

scholarly journals Nitrogen Availability and Use Efficiency in Wheat Crop as Influenced by the Organic-Input Quality Under Major Integrated Nutrient Management Systems

2021 ◽  
Vol 12 ◽  
Author(s):  
Ajay K. Bhardwaj ◽  
Deepika Rajwar ◽  
Rajender K. Yadav ◽  
Suresh K. Chaudhari ◽  
Dinesh K. Sharma
Keyword(s):  
Nutrient Management ◽  
Farmyard Manure ◽  
Wheat Crop ◽  
Growth Stages ◽  
N Availability ◽  
Integrated Nutrient Management ◽  
Inorganic Fertilizers ◽  
Available N ◽  
Stubble Retention ◽  
Use Efficiency

PurposeOne of the serious constraints for the integration of organics in soil fertility plans is the release and availability of nitrogen (N) to match the critical growth stages of a crop. The interplay between organic amendment characteristics and soil moisture conditions can significantly affect the nutrient release and availability, especially for dryland crops like wheat. In this study, the effects of integrated nutrient management strategies using diverse qualities of organic amendments on daily N mineralization and its availability to plants during the full growing season of the wheat crop were analyzed in a 10-year experiment.MethodsThe management included (1) F, inorganic fertilizers at 100% rate, compared to a reduced rate of inorganic fertilizers (55% N) supplemented with organic inputs via (2) GM, green manuring, (3) LE, legume cropping and its biomass recycling, (4) WS, wheat stubble retention, (5) RS, rice stubble retention, and (6) FYM, farmyard manure application, during the preceding rice season. Ion exchange resin (IER) membrane strips were used as plant root simulators to determine daily NH4+-N and NO3–-N availability in soil solution during the full wheat growing period.ResultsTotal available N for the full season was in the following order: GM (962 μg cm–2) > F (878 μg cm–2) > LE (872 μg cm–2) > FYM (865 μg cm–2) > RS (687 μg cm–2) > WS (649 μg cm–2). No significant differences were observed in NH4+-N availability throughout the cropping period as compared to NO3–-N which showed significant differences among management at critical crop growth stages.ConclusionLegume biomass incorporation (GM, LE) and farmyard manure (FYM) based management provided the most consistent supply equivalent to or even exceeding 100% inorganic fertilizers at several critical stages of growth, especially at tillering and stem elongation. Integration of organics in management increased nitrogen use efficiency 1.3–2.0 times, with cereal crop residue-based management having the highest efficiency followed by legume biomass incorporation.

Empirical relationships between temperature and nitrogen availability across North American forests

1992 ◽  
Vol 22 (5) ◽  
pp. 707-712 ◽  
Author(s):  
Xiwei Yin
Keyword(s):  
N Mineralization ◽  
Regional Scale ◽  
Mineral Soil ◽  
Published Data ◽  
N Availability ◽  
Net N Mineralization ◽  
Soil N ◽  
Litter Fall ◽  
Available N ◽  
N Pool

Published data were analyzed to examine whether nitrogen (N) availability varies along macroclimatic gradients in North America. Extractable N produced during 8-week aerobic laboratory incubation was used as an index of potential net N mineralization. Mean extractable N during the growing season in the forest floor plus top mineral soil was used as an index of the available N pool. Using multiple regression, potential net N mineralization was shown to increase with available N and with litter-fall N (R2 = 0.722). Available N increased with increasing total soil N and with decreasing mean January and July air temperatures (R2 = 0.770). These relationships appeared to hold also for deciduous and coniferous forests separately across regions. Results suggest that net N mineralization output under uniform temperature and moisture conditions can be generally expressed by variations of N input (litter fall) and the available soil N pool, and that the available soil N pool is predictable along a temperature gradient at a regional scale.

scholarly journals Positive plant–plant interactions expand the upper distributional limits of some vascular plant species

Ecosphere ◽  
2019 ◽  
Vol 10 (8) ◽  
Author(s):  
Morgan J. Raath‐Krüger ◽  
Melodie A. McGeoch ◽  
Christian Schöb ◽  
Michelle Greve ◽  
Peter C. Roux
Keyword(s):  
Plant Species ◽  
Vascular Plant ◽  
Plant Interactions ◽  
Vascular Plant Species ◽  
Distributional Limits ◽  
Plant Plant

Indices of soil nitrogen availability in five Tasmanian Eucalyptus nitens plantations

Soil Research ◽  
2004 ◽  
Vol 42 (7) ◽  
pp. 719 ◽  
Author(s):  
M. T. Moroni ◽  
P. J. Smethurst ◽  
G. K. Holz
Keyword(s):  
Soil Solution ◽  
Nitrogen Availability ◽  
Native Forest ◽  
N Availability ◽  
Eucalyptus Nitens ◽  
Soil Nitrogen Availability ◽  
Mineral N ◽  
Total N ◽  
Available N ◽  
Total P

Several soil analyses were used to estimate available N in surface soils (0–10 cm) over a 2-year period at 5 sites that supported 1- to 4-year-old Eucalyptus nitens plantations, and once in subsoils (10–120 cm) at 3 of these sites. Soils were derived from basalt (1 site previously pasture, 1 Pinus radiate, and 2 native forest) or siltstone (previously native forest). Soil analyses examined were total N, total P, total C, anaerobically mineralisable N (AMN), hot KCl-extractable N (hot KCl-N), and NH4+ and NO3– in soil solution and KCl extracts. AMN, KCl-extractable NH4+ and NO3–, and soil solution NH4+ and NO3– varied considerably with time, whereas hot KCl-N, total N, total P, and total C were temporally stable except for a gradual decline in total C with time at one site. Only total P was correlated with net N mineralisation (NNM) across all sites (r2 = 0.91, P < 0.05, n = 5). At 2–3 years after planting, soil solution and KCl-extractable NO3– dropped below 0.1 mm N and 1 μg N/g soil, respectively, at sites with NNM ≤24 kg N/ha.year (n = 3). Sites with NNM ≤24 kg N/ha.year also had ≤0.8 Mg P/ha. Although concentrations of indices of soil N availability decreased with depth, the contribution of subsoil (10–120 cm depth) to total profile N availability was estimated to be at least twice that of the top 10 cm. At an ex-pasture site, high concentrations of mineral N were found at 75–105 cm depths (KCl-extractable N, 289.3 μg N/g soil; 2.8 mm mineral N in soil solution), which may have become available to plantations as their root systems developed.

Larch litter and nitrogen availability in mixed larch–spruce stands. I. Nutrient withdrawal, redistribution, and leaching loss from larch foliage at senescence

1986 ◽  
Vol 16 (2) ◽  
pp. 321-326 ◽  
Author(s):  
J. C. Carlyle ◽  
D. C. Malcolm
Keyword(s):  
Nitrogen Availability ◽  
Field Measurements ◽  
N Availability ◽  
Mixed Stands ◽  
Available N ◽  
Low Field ◽  
Large N ◽  
Spruce Stands ◽  
And Storage ◽  
N Status

The growth and N status of Sitka spruce on deep peat sites low in available N is improved in the presence of larch. It has been suggested that larch stimulates N mineralization because of high N concentrations in its litter and the large N input resulting from its annual litter fall. However, while larch foliar N concentrations were shown to be high, marked withdrawal and storage in other tree components resulted in a relative and absolute impoverishment of the litter. P and K could be leached from senescing foliage in relatively large amounts, but the potential loss of N was low. Field measurements of throughfall substantiated this finding. Larch seemed extremely conservative in its use of N, suggesting that larch litter does not directly enhance N availability in mixed stands.

scholarly journals Continent-wide tracking to determine migratory connectivity and tropical habitat associations of a declining aerial insectivore

2012 ◽  
Vol 279 (1749) ◽  
pp. 4901-4906 ◽  
Author(s):  
Kevin C. Fraser ◽  
Bridget J. M. Stutchbury ◽  
Cassandra Silverio ◽  
Patrick M. Kramer ◽  
John Barrow ◽  
...  
Keyword(s):  
North American ◽  
Agricultural Landscape ◽  
Ground Cover ◽  
Light Level ◽  
Agricultural Landscapes ◽  
Habitat Associations ◽  
Migratory Connectivity ◽  
Population Declines ◽  
Long Distance ◽  
Breeding Populations

North American birds that feed on flying insects are experiencing steep population declines, particularly long-distance migratory populations in the northern breeding range. We determine, for the first time, the level of migratory connectivity across the range of a songbird using direct tracking of individuals, and test whether declining northern populations have higher exposure to agricultural landscapes at their non-breeding grounds in South America. We used light-level geolocators to track purple martins, Progne subis , originating from North American breeding populations, coast-to-coast ( n = 95 individuals). We show that breeding populations of the eastern subspecies, P. s. subis , that are separated by ca . 2000 km, nevertheless have almost completely overlapping non-breeding ranges in Brazil. Most (76%) P. s. subis overwintered in northern Brazil near the Amazon River, not in the agricultural landscape of southern Brazil. Individual non-breeding sites had an average of 91 per cent forest and only 4 per cent agricultural ground cover within a 50 km radius, and birds originating from declining northern breeding populations were not more exposed to agricultural landscapes than stable southern breeding populations. Our results show that differences in wintering location and habitat do not explain recent trends in breeding population declines in this species, and instead northern populations may be constrained in their ability to respond to climate change.

Ground cover increases spatial aggregation and association of insect herbivores and their predators in an agricultural landscape

2018 ◽  
Vol 33 (5) ◽  
pp. 799-809 ◽  
Author(s):  
Nian-Feng Wan ◽  
Xiang-Yun Ji ◽  
Lars Pødenphant Kiær ◽  
Shuang-Shuang Liu ◽  
Jian-Yu Deng ◽  
...  
Keyword(s):  
Agricultural Landscape ◽  
Ground Cover ◽  
Spatial Aggregation ◽  
Insect Herbivores

Soil and plant response to wellsite rehabilitation on native prairie in southeastern Alberta, Canada

2003 ◽  
Vol 83 (5) ◽  
pp. 507-519 ◽  
Author(s):  
A. M. Hammermeister ◽  
M. A. Naeth ◽  
J. J. Schoenau ◽  
V. O. Biederbeck
Keyword(s):  
Biomass Production ◽  
Plant Uptake ◽  
Nitrogen Availability ◽  
Carbon Allocation ◽  
Petroleum Industry ◽  
N Availability ◽  
Higher Plant ◽  
Available N ◽  
Native Prairie ◽  
Low Diversity

Rehabilitation of disturbed native prairie is a challenge facing many in the petroleum industry, with implications for prairie ecology and productivity. The purpose of this research was to examine the relative influence of four rehabilitation strategies on biogeochemical processes (i.e., nitrogen availability, plant uptake of nitrogen, biomass production, carbon allocation, and soil biological activity). Seven petroleum wellsites were selected on Chernozemic and Solonetzic soils in southeastern Alberta. Undisturbed native prairie was compared with four seeding treatments: not seeded, a low diversity seed mix commonly used by industry, a low diversity mix of species more typically dominant in native prairie, and a diverse seed mix. Flux of NO3− and NH4+were measured in situ using ion exchange membranes. Soil total C and N were lower and available N higher as a result of disturbance. In the seeded treatments, biomass production was higher and soil nitrogen flux was lower due to higher plant uptake than in the unseeded treatment. Higher initial N availability favoured species with rapid growth and colonization rates, particularly Agropyron dasystachyum [(Hook.) Scribn.] and Agropyron trachycaulum [(Link) Malte]. Seed mix composition and species attributes were deemed to have greater influence on N cycling and biomass production than seed mix diversity. Key words: Nitrogen cycling, plant competition, secondary succession, wheatgrass, biodiversity, prairie

Nitrogen transformations in feather moss and forest floor layers of interior Alaska black spruce ecosystems

1984 ◽  
Vol 14 (2) ◽  
pp. 278-290 ◽  
Author(s):  
M. G. Weber ◽  
K. Van Cleve
Keyword(s):  
Forest Floor ◽  
Black Spruce ◽  
Vascular Plant ◽  
N Uptake ◽  
Nitrogen Transformations ◽  
Organic Matter Quality ◽  
Available N ◽  
Moss Species ◽  
Feather Moss ◽  
Interior Alaska

Permafrost-free and permafrost-dominated black spruce (Piceamariana (Mill.) B.S.P.) ecosystems in interior Alaska were treated with low addition levels of high enrichment isotope (<1% of the total nitrogen pool with 99 at.% excess 15N) to describe nitrogen dynamics through pools of selected forest floor components. A thick carpet of mosses, made up primarily of the feather moss species Hylocomiumsplendens (Hedw.) B.S.G. and Pleuroziumschreberi (B.S.G.) Mitt, seemed to play a vital role in the nitrogen economy of the forest floor. Nitrogen, quickly immobilized in the moss layers (green, brown) and retained there, was released very slowly to the lower organic layers (021 + 022) where most of the vascular plant roots were located. 15N uptake by the vascular understory was minimal, as was15Nexport via the soil solution. Periodic mineralization episodes, more frequent and dynamic at the permafrost-free site (where C/N ratios were lower), were largely restricted to the moss layers since available N fractions in deeper forest floor layers incorporated little label over the 3-year period. In the lower layers of the forest floor (021 + 022) temperature rather than organic matter quality appeared to be the overriding factor controlling N flow.

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