Annual Harvest Research Articles

Assessment of the resource base of Rumex tianschanicus Losinsk. in the mountain regions of southeastern Kazakhstan

Inventory of stock economically valuable plant species is one of the urgent tasks in the regional cadastral assessing of plant resources. The results of this will be applied to conduct state monitoring and the flora cadastre in the Republic of Kazakhstan. Genus Rumex L. belongs to Polygonaceae Juss. family and represented by 27 species in the flora of Kazakhstan including 15 medicinal which used in folk and official medicine. For the first time undertaken a cadastre assessment of current ecological state of the flora and plant resources in Almaty region, the stocks of plant raw material of the valuable medicinal Rumex tianschanicus, have been identified and taken into account in 2021-2022 years on the 3 floristic territories (24. Dzhungarsky Alatau, 25. Zailiysky Kungei Alatau, 25a. Ketmen-Terskey Alatau) and 4 administrative (Eskeldinsky, Kegensky, Raiymbeksky, Uigursky) districts. The resource survey of the territories carried out by a route-reconnaissance method using generally accepted resource-study and geobotanical methods. On the surveyed territory the total operational reserve of air-dry underground part of Rumex tianschanicus was 169.5 tons on 113.3 hectares with a total volume of possible annual harvesting of 17.0 tons of air-dry plant raw materials. For commercial harvesting thickets were isolated ridges of Ketmen (Uigur district) and Terskey Alatau (Raiymbek district) which located within 25a floristic region in the southeast of the Almaty region.

Stocks of <i>Onobrychis</i> (Fabaceae) Raw Materials in the Republic of Azerbaijan

Abstract—The distribution areas and resources of Onobrychis Hill species (the sainfoins) in Azerbaijan were studied. The areas of thickets and the volumes of potential annual harvesting of 19 species, out of 22 common for Azerbaijan, were determined. It was found that sainfoins occupy an area of 1059.6 ha. The biological stock of the above-ground (herb and shoots) and underground (roots) parts in the studied areas is 291.133, 33.715 kg and 317.003 kg, respectively; the exploitable volume is 198.490, 22.371 kg and 214.834 kg, respectively; the potential volume of annual harvesting is 44.624, 14.321 and 5.593 kg of air-dry raw materials, respectively.

Forest Disturbance and Disease: Exploring the Effects of Tree Harvesting Area on Cryptococcus gattii sensu lato Infection Risk, Vancouver Island, Canada, 1998-2014.

The disturbance of colonized trees and soil, such as through forestry activities, has been proposed to disperse soil- and tree-inhabiting fungal pathogens. Cryptococcus gattii sensu lato is one such pathogen that was detected on Vancouver Island, British Columbia, Canada, beginning in 1999 and caused human and animal illness. Our aim was to determine if C. gattii s.l. human case incidence on Vancouver Island was correlated with the intensity of landscape-level tree harvesting occurring near human settlement areas. We created buffers around human settlement areas with radii increments of , from 2.5 to , and summed the area of annual tree harvests occurring within each buffer zone. We then performed Spearman rank-order correlation to measure the association between case incidence and annual tree harvest intensity at each radius from 1998 through 2014. The incidence of C. gattii was positively correlated with tree harvesting intensity only at distances of (, ) and (, ) from human settlement areas. As annual tree harvesting area increased between 1999 and 2003, so did annual C. gattii incidence in humans, before both plateaued around 2002 and decreased after 2007. Our findings suggest that tree harvesting plays a role in the spread of C. gattii on Vancouver Island. This may be due to tree cutting or soil disturbance facilitating the aerosolization of spores to increase infection risk. This research also illustrates the contribution that geographic information systems can make to public health research on environmental disturbance and disease outbreaks. https://doi.org/10.1289/EHP12396.

Large global variations in the carbon dioxide removal potential of seaweed farming due to biophysical constraints

Estimates suggest that over 4 gigatons per year of carbon dioxide (Gt-CO2 year−1) be removed from the atmosphere by 2050 to meet international climate goals. One strategy for carbon dioxide removal is seaweed farming; however its global potential remains highly uncertain. Here, we apply a dynamic seaweed growth model that includes growth-limiting mechanisms, such as nitrate supply, to estimate the global potential yield of four types of seaweed. We estimate that harvesting 1 Gt year−1 of seaweed carbon would require farming over 1 million km2 of the most productive exclusive economic zones, located in the equatorial Pacific; the cultivation area would need to be tripled to attain an additional 1 Gt year−1 of harvested carbon, indicating dramatic reductions in carbon harvest efficiency beyond the most productive waters. Improving the accuracy of annual harvest yield estimates requires better understanding of biophysical constraints such as seaweed loss rates (e.g., infestation, disease, grazing, wave erosion).

Alley cropping tree lines alter temperature and light quantity and influence daily growth rates of grassland

AbstractTrees alter microclimate and radiation budget in alley cropping systems, which in turn change physiological processes of the grassland component. The influence of the trees on grassland growth depends on the climate zone as well as possibly on weather conditions during the respective growth interval. The proportion of shade‐tolerant species in the grassland further modifies the tree effect on grassland growth, as well as the number of annual harvests. We studied the effect of distance and orientation relative to the tree line (tree line in the South‐West vs. North‐East) on growth rates of the adjacent grassland with two cutting frequencies (frequent vs. infrequent) in an alley cropping system with grassland of two different vegetation compositions (diverse vs. grass‐clover) and willow clones. Microclimate parameters and radiation were measured at the points where growth rates were determined to better characterize the effect of position relative to the tree line. Growth rates differed significantly (p < 0.05) depending on the distance to the trees and annual biomass accumulation amounted to 389 ± 13.5 g m−2 in the center vs. 321 ± 10.0 g m−2 with trees in the North‐East vs. 292 ± 9.2 g m−2 with trees in the South‐West of the transect position. Lower growth rates occurred at positions with lower light quantities close to the trees, namely the position with the trees adjacent in the South‐West. Temperature and relative humidity differences between the distances were significantly (p < 0.05) affected by distance to the tree line, but differences in neither soil nor air temperatures between the distances affected growth rates. Vegetation composition mediates the influence of the trees: the difference between positions was more pronounced in the diverse vegetation composition with higher productivities in the center between the alleys, but also with higher overall sward productivity.

Depleting soil nutrients through frequency and timing of hay cutting on floodplain meadows for habitat restoration and nutrient neutrality

Floodplain meadows support a high level of botanical diversity because the nutrient inputs from flood sediments are balanced by nutrient offtake via an annual hay harvest, leading to nutrient neutrality. This prevents a build-up of nitrogen (N) and phosphorus (P) and depletes excess nutrients, which mitigates eutrophication in catchment areas and prevents reductions of biodiversity through competitive exclusion.A replicated field trial was undertaken in floodplain meadows in central England, with the aim of comparing the nutrient offtake potential throughout the growing season with a single or a double-cut system, and determining when haymaking should occur to maximise nutrient offtake and nutritional value of the hay. Additionally, farmer perspectives were gathered to investigate the practicality of implementing a second hay cut.The results revealed that a single summer hay cut may be sufficient to balance nutrient inputs. However, a double-cut, where a second harvest replaces autumn grazing, has the potential to actively lower N and P levels, removing 8.69 g m−2 N and 0.80 g m−2 P. Maximising time between cuts in a double-cut system provides the greatest opportunity for nutrient removal.Temperature is a key driver of plant growth. The relationship between accumulated thermal time and calendar date in central England has advanced by around two weeks between 1961–1990 and 1991–2020. Delayed hay cutting under agri-environment scheme restrictions may be increasingly detrimental to botanical diversity with advancing seasons, due to lower nutrient removal under a single-cut system, and increased competitive exclusion. Taking a first cut at the mid-summer peak in offtake potential, currently 20–30 June in central England, and a second cut in the autumn offers an opportunity to deplete excess nutrients. Whilst farmers identify practical and financial concerns that may make a second cut prohibitive in some cases, this could be overcome by, e.g., demonstrating the higher-than-expected nutritional value of hay from a second cut.

Forest Land Expectation Value or Maximum Sustained Yield? Resolving A Long-Standing Paradox

The Faustmann formula, equivalent to the land expectation value (LEV), yields the present value, starting with bare land, of an infinite series of future timber rotations for a stand. If this formula is used to find the rotation age that maximizes the present value, a lower annual harvest will result when compared to a maximum sustained yield (MSY) regime for an ownership with many stands. However, the LEV is strongly preferred by economists. This is the LEV vs. rents paradox. Herein, this paper demonstrates that an infinite series of annual harvests for an ownership under an even flow regime, discounted to the present using any interest rate, will provide the same optimal rotation age as the time of the peak MAI for a single stand, though with different estimates for the profitability, depending on the interest rate. Thus, rotations producing the MSY and the maximum financial return are identical when analyzed at the ownership scale but are not the same when based on the analysis at the stand scale using the Faustmann formula (LEV). This is the solution to the paradox. The formulas for internal rate of return (IRR) and the land valuation for transaction purposes are also presented.

Effective sources of powdery mildew resistance among spring bread wheat for the northwest of the russian federation

Background. Bread wheat (Triticum aestivum L.) is one of the world’s main food crops. In Russia, its gross harvest in recent years has reached 21.079 million tons. Blumeria graminis is one of the most harmful diseases of bread wheat. Annual harvest losses can reach 10–30%. In Leningrad Province, powdery mildew appears almost every year on cereals. Development of cultivars resistant to powdery mildew is the most important trend in spring bread wheat breeding. Its progress is determined by new sources of effective resistance genes and their incorporation into promising spring bread wheat cultivars. The purpose of this work was to retest the seedling and adult resistance to powdery mildew in spring bread wheat accessions selected over a period of more than twenty years and redefine the effectiveness of disease resistance sources at the present time.Materials and methods. Since 2000, VIR has conducted a search for powdery mildew resistance among 1283 spring bread wheat accessions. The identified 36 sources of adult and seedling powdery mildew resistance were reevaluated in 2022. Field and laboratory studies into the resistance to the pathogen were performed according to VIR’s guidelines.Results and discussion. In 2022, field and laboratory studies of spring bread wheat cultivars revealed accessions with resistance to the pathogen in all phases of plant development. Six sources remained resistant to powdery mildew for 13–22 years, another six showed resistance for 7–12 years, and 8 cultivars were immune for 6 years. Resistance of 9 accessions identified for this trait in 2020 was confirmed.Conclusion. Field and laboratory research into the resistance of spring bread wheat accessions to the pathogen identified sources retaining seedling and adult resistance to the Leningrad population of powdery mildew for 7 years or more. These accessions are recommended for use in wheat breeding programs.

Annual changes in water quality and sportfish community structure following commercial harvest of common carp and bigmouth buffalo

Martin A. Simonson, Michael J. Weber, Grace M. Wilkinson and Andrew R. Annear. 2023. Annual changes in water quality and sportfish community structure following commercial harvest of common carp and bigmouth buffalo. Lake Reserv Manage. XX:XXX–XXX. Commercial harvest of common carp (Cyprinus carpio; hereafter carp) and bigmouth buffalo (Ictiobus cyprinellus; hereafter buffalo) populations had little detectable effect on shallow lake ecosystems. We tested whether carp and buffalo biomass removal affects limnological variables and fish community metrics across 6 shallow, natural lakes of northwestern Iowa using mixed effects models. Annual commercial harvest of carp ranged from 0 to 71 kg/ha; annual harvest of buffalo ranged from 0 to 356 kg/ha. Biomanipulation (i.e., commercial harvest) of carp was associated with decreases in soluble phosphorus and nitrogen concentrations, but not total phosphorus or nitrogen. Buffalo harvest was unrelated to annual changes in nutrient concentrations but was associated with reductions in chlorophyll a and phycocyanin concentrations. Secchi disk transparency and total suspended solids were unrelated to carp and buffalo harvest. Carp harvest was associated with reduced biomass of large cladocerans but no other zooplankton biomass densities; buffalo harvest was unrelated to zooplankton biomass. Species richness and rake density of aquatic macrophytes were unrelated to carp and buffalo harvest. Carp and buffalo harvest was unrelated to changes in most indices of sportfish abundance, condition, and size distribution. Our results suggest harvest of carp and buffalo <71 kg/ha has little effect on abiotic and biotic ecosystem components on short time scales and highlights the challenges associated with shallow lake restoration.

Rockrose Land Management: Contribution of Periodic Harvesting to Increase Value and to Control Cistus ladanifer L. Shrublands

Cistus ladanifer L. (Cistaceae) occupies extensive areas as a dominant species (shrublands) or is associated to other major forest typologies in the Iberian Peninsula. Cistus ladanifer shrublands are mostly present in oligotrophic lands with little valorisation and management and as they develop over the years (up to 20-years-old) they promote the ignition and perpetuation of fire. To contribute to the proper management and valorisation of such systems, a 5-year-old dense shrubland was evaluated for its labdanum resin, seeds, and biomass productivity using different non-destructive harvest periodicities (annual and biennial) and seasons (early, mid-, and late summer), in a two-year case-study. Annual harvest modality maximized labdanum resin productivity (reaching 230 ± 50 kg∙ha−1∙2 years−1 at late summer) and photosynthetic biomass productivity. In contrast, a biennial harvest yielded significant amounts of more diversified products. It maximized seeds productivity (reaching 75 ± 41 kg∙ha−1∙2 years−1 independently of the summer season) and lignified biomass. However, it also reached a labdanum resin productivity of 134 ± 20 kg∙ha−1∙2 yearrs−1 at late summer and a photosynthetic biomass productivity around two times lower than the annual harvest. In this study, we propose two modalities of periodic harvest to be considered as proper long cycle management practices of rockrose lands. It intends to minimize fire risks, break the vegetation auto-succession mechanism, and increase profit from non-productive lands based on three direct outputs with a myriad of applications and valorisation pathways.

Subsistence harvest of beluga or white whales (Delphinapterus leucas) in northern and western Alaska, 1987–2006

Four stocks of beluga or white whales (Delphinapterus leucas) are hunted by Alaska Natives in northern and western Alaska. These are the Beaufort Sea, eastern Chukchi Sea, eastern Bering Sea and Bristol Bay stocks. Since 1987, the Alaska Beluga Whale Committee has monitored the subsistence harvests of belugas from these stocks. During this 20 year period, the total landed harvest for the four stocks combined (adjusted for years with missing data) ranged from 208 in 1995 to 494 in 1988, with a 20 year average of 323 per year. For individual stocks the average annual landed harvests for 1987–2006 were: Beaufort Sea – 41; Chukchi Sea – 62; eastern Bering Sea – 191; and Bristol Bay – 20. There was no significant longterm trend (p&gt;0.05) in the rate of harvesting for any stock from 1987–2006. Average landed harvests relative to estimated stock size were: 0.1% for the Beaufort Sea (0.4% including belugas harvested from the Beaufort Sea stock by Canadian hunters); 1.7% for the eastern Chukchi Sea; 1.1% for the eastern Bering Sea; and 1.1% for Bristol Bay. The success of beluga harvest monitoring in Alaska is due to the cooperation of beluga hunters from more than 40 small coastal communities who report their harvests to the Alaska Beluga Whale Committee (ABWC). Through the ABWC, beluga hunters have been able to formalise their role in managing their subsistence resources.

Field Assessment and Identification of Sugar-cane Weevil Borer, Rhabdoscelus Obscurus (coleoptera: Curulionidae), in Fiji

Sugarcane is one of the most important crops grown in Fiji contributing much to the country's socioeconomic success. It was brought to Fiji by the early voyages during the European colonization. The sugar industry in Fiji not only provides revenue but is also a source of income for most people in the Western division of the country. Sugarcane is attacked by a wide range of insects and diseases resulting in significant damage in all stages and parts of the crop. One of the major pest of sugarcane is the cane weevil borer, Rhabdoscelus obscurus (Coleoptera: Curulionidae). The larva of this beetle causes most of the economic damage by infesting the soft tissues within the internodes of the cane stalk which results in physiological changes thus decreasing sugar content and quality. This loss in biomass and sugar content necessitates the need for control and subsequent eradication of the pest. This review reports the method of identifying cane weevil borer (CWB) in sugarcane in Fiji. Visible scars, cracks and tunnels are evidence of the presence of CWB and sugarcane borer damage is estimated by determining the percentage loss in weight and height caused during the annual harvesting survey. Monitoring and accurate identification of the pest is important for effective control.

Contribution of a forest rehabilitated with various schemes of agroforestry in storing carbon

Rehabilitation of degraded forest areas in the Forest Research and Education (FRE) Wanagama 1 was conducted by planting trees and crops in various agroforestry schemes. This approach is aimed to establish a successful plantation while allowing local people gaining benefits through farming in the forest land. At present, the FRE Wanagama 1 has several forests stands with various ground cover vegetations. This research was carried out to estimate the contribution of the forest for storing carbon, by estimating aboveground biomass (stand, ground cover, and litter) as well as soil organic carbon. Results of this study reveal that from the above-ground perspective, Swietenia stand stores the greatest carbon, approximately (229.35 Mg.ha−1), followed by those of Eucalyptus stand (135.91 Mg.ha−1), Acacia stand (69.01 Mg.ha−1), and Gliricidia stand (59.35 Mg.ha−1). The lowest level of carbon storage is observed in Melaleuca stand (5.36 Mg.ha−1) due to annual harvest of the leaves for oil production. The highest soil organic carbon was found in Swietenia stand (135.10 Mg.ha−1), followed by those of Gliricidia stand (131.26 Mg.ha−1), Eucalyptus stand (107.53 Mg.ha−1), and Acacia stand (105.61 Mg.ha−1). Whereas the lowest soil organic carbon was found in Melaleuca stand (67.59 Mg.ha−1). Up to 61.78% and 92.04% of the total carbon in each stand and soil can be used to store carbon, respectively. However, the agroforestry scheme must be wisely chosen, otherwise they will be significat reduction in the capability of the stand and the soil in storing carbon.

Costa Rica after Coffee: The Co-op Era in History and Memory

In 1986 the field of Costa Rican history underwent a dramatic shift thanks to Lowell Gudmundson's pathbreaking Costa Rica before Coffee. The title of Gudmundson's most recent publication highlights the connection the author makes between these two monographs. In Costa Rica after Coffee, Gudmundson examines the role coffee cooperatives played in creating conditions that supported the upward mobility of small-scale coffee farmers in the post–1948 Civil War era. Additionally, he considers the political, demographic, and geographical consequences of this triumph. This analysis builds on Gudmundson's work in Costa Rica before Coffee, where he demonstrated how coffee's introduction in the mid-nineteenth century transformed Costa Rica, by ushering in a period of widespread prosperity. Indeed, this crop provided both small and large landowners with the conditions for economic advancement.In just over one hundred pages Gudmundson ambitiously seeks to historically define three processes of considerable importance to contemporary Costa Rican society. First, he explores how small- and medium-scale coffee producers successfully organized cooperatives in the post-1948 period and the broad socioeconomic consequences of their efforts. Second, Gudmundson interrogates the causes and consequences of reduced coffee production in more recent decades. Last, he sets out to uncover what can account for the dramatic political shift from a Social Democratic to a Center-Right political platform on the part of the nation's once dominant National Liberation Party, or PLN.At first, the PLN's transformation may appear unrelated to the issues of cooperative development and declining coffee production, but Gudmundson skillfully makes use of census data, probate records, oral histories, participant observation, and a variety of secondary sources to convincingly argue that these processes are deeply intertwined.The book's introduction and first chapter provide readers with a basic overview of Costa Rica's post-1948 political history. Gudmundson examines the fundamental role small- and medium-scale coffee producers played in securing the PLN's political victories after 1948. The PLN courted farmers’ votes through populist ideals, anti-communist rhetoric, and policies that supported the formation of coffee cooperatives.In chapters 2 and 3, Gudmundson researches the first generation of cooperative farmers. These chapters underscore the social transformation that the cooperatives brought their members, who invested in the dream of a cooperative to process their crops. Gudmundson concludes this analysis by arguing that the coffee boom of the 1970s, which saw production rise alongside coffee prices, affirmed to many observers that the PLN's social democratic model of agrarian-centered, cooperative-based development had succeeded.In 1989, the system would implode with the collapse of the International Coffee Agreement, or ICA. Chapter 4 analyzes how farmers adapted to this dramatic event, which saw global coffee prices plummet. Post-ICA, the emergence of private microbeneficios that process small quantities of beans in situ allowed farmers to create new opportunities based on quality. These microprocessors participate in annual competitions for “best coffee” awards. The consequences of winning are real. Indeed, a 2017 winner was paid $8,000 for each fanega of coffee they sold, while the average producer earned just $140 per fanega. In 2015, microprocessors received over a third of the annual harvest. The microprocessors’ focus on quality and their ability to generate profits have clearly allowed them to chip away at the cooperatives’ once near monopoly on coffee processing.In chapter 5, Gudmundson explains how the first generation of cooperative farmers’ prosperity permitted their children to earn university degrees and contribute to the formation of a new economy ripe with opportunities for educated workers. An unintended consequence is that coffee farmers today are aging without heirs to replace them, leading many, especially in the Central Valley, to sell their farms to developers. Gudmundson argues that as coffee production has steadily declined, aging farmers and their professional children have increasingly come to see free trade, decreased social spending, and other neoliberal policies as favorable to their interests. In this context, the PLN's recent rightist turn might best be understood as a reflection of a broader shift in the economic and political outlook of this party's traditional base.Gudmundson deserves high praise for not only producing a smartly argued monograph but doing so in just over one hundred pages. The book, however, is dense, requiring sustained attentive reading despite the clarity of Gudmundson's prose. Ultimately, Costa Rica after Coffee affirms Gudmundson's prominent position in the field of Costa Rican studies and promises to become required reading for Costa Ricanists. This book additionally will appeal to Latin Americanists interested in the process of cooperative development.

Management proposal of a naturally occurring wetland modeled as a constructed wetland

Environmental management and restoration aim to accelerate the recovery of ecosystems that have been affected by human activities. This paper presents the diagnosis and management proposal for the Valsequillo wetland, Puebla, Mexico. The study site is a natural wetland dominated by water hyacinth (Eichhornia crassipes) which performs a biofiltration process by reducing the pollutant load of the water. To increase the efficiency of the wetland, an annual harvest plan is proposed in this work. However, the ideal amount of biomass to harvest is unknown. In order determine the optimal annual harvest plan, this natural wetland was modeled as if it were a surface flow wetland by using the equations described. A total of 48 surface water samples were collected in three different seasons of the year (dry, rainy, and winter) and 34 water quality physicochemical parameters were measured. Additionally, two water quality indices were determined, namely: Overall Index Pollution (OIP) and Heavy Metal Evaluation Index (HEI) to determine the degree of contamination in different zones of the study area. The model results showed that in order to achieve the desired removal of total phosphorus (TP) or chemical oxygen demand (COD), 274 ha or 306 ha of aquatic plants must be harvested, respectively. The results of the modeling showed that this action will optimize the function of the wetland by improving the removal of total suspended solids (TSS, 6%), total nitrogen (TN, 24%) TP (31%), chemical oxygen demand (COD, 11%) and biochemical oxygen demand (BOD5, 101%).

Increasing the value of Phragmites australis straw in a sustainable integrated agriculture model (SIAM) comprising edible mushroom cultivation and spent mushroom substrate compost

Because of the regular annual harvest, Phragmites australis used in wetland protection produces an abundance of straw, resulting in a large amount of straw waste. As a result, the extra straw should be used in a convenient and efficient manner. A comprehensive analysis of P. australis straw use in Pleurotus cultivation and spent mushroom substrate compost was performed in this study to increase its value. The lignocellulose content in the straw was shown to meet the nutritional requirements of the Pleurotus mushroom. Immediately thereafter, the replacement of bagasse with P. australis proved to be reasonable for Pleurotus eryngii substrate and could generate a profit of ¥17,400 per 10,000 cultivation bags. Substituting P. australis for approximately 20 % to 40 % of bagasse is recommended for Pleurotus ostreatus cultivation and can yield a profit of approximately ¥16,000. Spent mushroom substrate compost was confirmed to increase the organic matter content, and post-compost use of this substrate as a fertilizer could increase economic income by approximately ¥1000 for every 10,000 bags. Overall, this recycling pathway for P. australis resources presents positive ecological and social benefits, and the model is a sustainable and eco-friendly solution for agricultural waste worthy of promotion and further application.

CASE SELECTION AND DATA DESCRIPTION FOR THE WORKING LABOURS IN A RESIDENTIAL BUILDING

Nowadays, many construction companies are facing with ever stricter environmental impacts and changing, innovative material markets in which customers are being increasingly aware of environmental impacts. In today's societies the built environment accounts for 10% of global economic, activity, consumes 40% of the world's material and energy production, accounts for 70% of the fresh water consumption and uses 25% of the annual global wood harvest. As we know, the construction of a building consisting of many activities that begins with Earthwork and ends with handover of the building to the customer by the contractor. Hence it includes many different construction materials which cause great impacts to the environment. Not only the building materials, but also the pollution producing during the period of construction and demolition of a building creates largest impact to the surrounding environment.

Incorporating distribution shifts and spatio-temporal variation when estimating weight-at-age for stock assessments: a case study involving the Bering Sea pollock (Gadus chalcogrammus)

AbstractEnvironmental conditions can create spatial and temporal variability in growth and distribution processes, yet contemporary stock assessment methods often do not explicitly address the consequences of these patterns. For example, stock assessments often assume that body weight-at-age (i.e. size) is constant across the stocks’ range, and may thereby miss important spatio-temporal patterns. This is becoming increasingly relevant given climate-driven distributional shifts, because samples for estimating size-at-age can be spatially unbalanced and lead to biases when extrapolating into unsampled areas. Here, we jointly analysed data on the local abundance and size of walleye pollock (Gadus chalcogrammus) in the Bering Sea, to demonstrate a tractable first step in expanding spatially unbalanced size-at-age samples, while incorporating fine-scale spatial and temporal variation for inclusion in stock assessments. The data come from NOAA’s bottom trawl survey data and were evaluated using a multivariate spatio-temporal statistical model. We found extensive variation in size-at-age at fine spatial scales, though specific patterns differed between age classes. In addition to persistent spatial patterns, we also documented year-to-year differences in the spatial patterning of size-at-age. Intra-annual variation in the population-level size-at-age (used to generate the size-at-age matrix in the stock assessment) was largely driven by localized changes in fish size, while shifts in species distribution had a smaller effect. The spatio-temporal size-at-age matrix led to marginal improvement in the stock assessment fit to the survey biomass index. Results from our case study suggest that accounting for spatially unbalanced sampling improved stock assessment consistency. Additionally, it improved our understanding on the dynamics of how local and population-level demographic processes interact. As climate change affects fish distribution and growth, integrating spatiotemporally explicit size-at-age processes with anticipated environmental conditions may improve stock-assessment forecasts used to set annual harvest limits.

Spring Wheat–Summer Maize Annual Crop System Grain Yield and Nitrogen Utilization Response to Nitrogen Application Rate in the Thermal–Resource–Limited Region of the North China Plain

Spring wheat–summer maize (SWSM) annual crop systems were formed to satisfy the maize grain mechanized harvest thermal requirement in the thermal–resource–limited region of the North China Plain. However, the nitrogen (N) application rate effect on SWSM annual yield formation, N accumulation and utilization were barely evaluated. Two–year field experiments were conducted to evaluate the effects of the N application rate on the annual yield of SWSM, observe N accumulation and utilization, and identify the optimized N application. The experiments were conducted under 5 N levels of 0 (N0), 180 (N180), 240 (N240), 300 (N300), and 360 (N360) kg ha−1. The results showed that spring wheat, summer maize and annual cereal yield under the N240 and N480 treatments obtained the highest grain yield (GY) of 5038, 1282 and 16,320 kg ha−1, respectively, and the optimal N application rate was estimated using a linear–plateau model to be 231–307, 222–337 and 463–571 kg ha−1 with maximum GY of 4654–5317, 11,727–12,003 and 16,349–16,658 kg ha−1, respectively. With the increase in the N application rate, the dry matter accumulation (DM) were significantly increased by 16.9–173.5% for spring wheat and 11.1≈–76.8% for summer maize, respectively; and the annual cereal DM was 15.1–179.7% greater than that with N0 treatment, respectively. Spring wheat, summer maize and the annual cereal total N accumulation (TN) under N360 and N720 treatments were significantly increased by 5.4–19.1%, 16.6–32.3% and 11.5–26.2%, respectively, compared to the other treatments; however, N use efficiency for biomass and grain production (NUEbms and NUEg) were decreased significantly by 10.9–13.6% and 8.9–20.7%, 6.8–13.8% and 12.2–15.6%, and 5.5–11.7% and 10.0–16.0%, respectively. Meanwhile, the N partial factor productivity (PFPN), N agronomy use efficiency (ANUE), N recovery efficiency (NRE) and N uptake efficiency (NEupk) under the N240 treatment for spring wheat and summer maize obtained high levels of 20.99 and 47.01 kg−1, 9.27 and 16.35 kg−1, 32.53% and 32.44%, and 0.85 and 0.72 kg−1, respectively. Correlation analysis showed that the N application rate, TN and NEupk played significantly positive roles on GY, spring wheat spilke grain number, summer maize ear grain number and 1000–grain weight, DM LAImax and SPADmax, while NUEbms, NUEg, PFPN and ANUE always played negative effects. These results demonstrate that spring wheat, summer maize and annual cereal obtained the highest GY being 4654–5317, 11,727–12,003 and 16,349–16,658 kg ha−1 with the optimal N application rate 231–307, 222–337 and 463–571 kg ha−1, respectively, which provide N application guidance to farmer for spring wheat–summer maize crop systems to achieve annual mechanical harvesting in the thermal–resource–limited region of the North China Plain.

Individual-tree growth models for lodgepole pine (Pinus contorta) in Iceland

Lodgepole pine (Pinus contorta subsp. contorta) is one of the most important tree species planted in Iceland. The current plantation area is 7100 ha, the first plantations being 80 years old. This study presents models for simulating the development of Icelandic lodgepole pine plantations on an individual-tree basis. The model set consists of a site index model, tree height model, and diameter increment model. Data were collected in 35 permanent sample plots with measurement intervals ranging from 3 to 14 years. The total number of diameter increment observations was 3664. Regression analysis was used in site index and height modelling, and both regression analysis and optimization were tested in diameter increment modelling. An optimization-based model was evaluated to be the most suitable for growth simulations. The use of the developed model set was demonstrated in management optimizations, where the rotation length and cutting schedule were optimized for two young sample plots, one representing poor sites and the other good sites. The optimizations showed that planting is not profitable on poor sites if the discount rate is 4% or higher. The mean annual stem wood harvest was 2.7–4.1 m3ha-1a-1 on the poor site and 8.3–11.7 m3ha-1a-1 on the good site.