Selective Harvesting Research Articles

Driving mechanisms of productivity stability vary with selective harvesting intensities in a mixed broad-leaved Korean pine forest

Key messageWe found that the stabilizing mechanisms for forest productivity varied across harvesting intensities in a mixed broad-leaved Korean pine forest. Effects of overyielding at high species richness and species asynchrony occurred only in unharvested and lightly harvested plots, whereas asymmetries between individuals of different size contributed significantly to stabilizing productivity when harvestings became intensive.ContextUnderstanding the driving factors of forest ecosystem stability has become increasingly crucial in forest management. However, it remains unclear whether and how the stabilizing mechanisms of forest productivity might be influenced by management practices.AimsWe related the temporal stability of aboveground biomass productivity to harvesting history. We further tested how three key driving mechanisms of stability might be modulated by selective harvesting intensities.MethodsBased on a 10-year monitoring (five repeated tree inventories) of a mixed broad-leaved Korean pine forest in Northeastern China recovering from selective harvesting, we examined the relative importance of two diversity-dependent mechanisms (overyielding and species asynchrony) and one size-dependent mechanism (asymmetric growth) for productivity stability across a wide range of intensities (0–73.4% basal area removed).ResultsWe found that selective harvesting significantly lowered the productivity stability, species asynchrony, and growth dominance coefficient. Growth dominance coefficient had an overall stronger effect on stability than species richness and asynchrony. Moreover, the strengths of stabilizing mechanisms varied across harvesting intensities: effects of overyielding at high species richness and species asynchrony were detected only in unharvested and lightly harvested plots, whereas the explanatory power of growth dominance coefficient outweighed the diversity-related variables when harvesting became intensive.ConclusionsWe emphasized the importance to consider both diversity- and size-related explanatory variables as potential mechanisms for the temporal stability of forest productivity. In fact, how growth is partitioned among trees of different species as well as sizes may co-determine the response of forest stability to disturbances.

Morpho-Physiological Traits and Phytochemical Compositions of Coffea canephora Beans from Lampung for Various Harvesting Stages and Soaking Durations

Coffea canephora, also known as Robusta, is one of the coffee species that dominates production in Indonesia. The morphology, physiology, and phytochemistry of Canephora coffee beans are affected by many factors, such as the fruit harvesting time and post-harvest processing. The maturity stage of coffee fruits at harvest time and post-harvest management will affect the various morpho-physiological and phytochemical compositions of the coffee beans. This research aimed to observe Canephora coffee beans’ morpho-physiological and phytochemical compositions for various harvesting stages and soaking durations. The experiment was conducted using a completely randomized design (CRD). It tested eight treatments, a combination of harvesting times (H1 = only red fruit/ripe stage, H2 = green, yellow, red fruits/strip-picking stage) and soaking durations (S0 = 0, S1 = 12, S2 = 24, and S3 = 36 h) with four replications. The main observations were the morpho-physiological traits (size, weight, color, moisture content, bean yield) and the phytochemical compositions (TPC = total phenolic content, AA = antioxidant activity, and CC = caffeine content) of the coffee bean before and after the drying process. Based on morphological characteristics (bean size and weight before drying), the highest value came from selective harvesting or ripe-picking only without soaking duration application (H1S0). While the selective harvesting method with a 24 h soaking duration showed a high value for the color trait (L and b*), the treatment that affected the color trait after drying was the strip-picking harvesting method without soaking (a* and b*). On the other hand, the phytochemical contents had H1S0 for the highest TPC and AA values. In contrast, H1S1 or selective harvesting, with 12 h of soaking, had the highest value of CC. The optimum combination of harvesting methods and soaking duration will improve the quality of the Canephora coffee beans.

Simulation of stand dynamics for miombo woodlands in Kitulangalo Forest Reserve, Morogoro, Tanzania

ABSTRACT Miombo woodlands constitute the most extensive type of forest cover within South and East Africa, Tanzania in particular, and they are seriously threatened by intensive degradation and deforestation. The dynamics of miombo stands were examined in this study using a simple simulation system applied to experimental stands at the Kitulangalo Forest Reserve (KFR) in Tanzania. Prediction of tree-level diameter increment, mortality, and ingrowth across species groups with empirical models based on data from experimental sites constituted the essential elements of the simulation system. Diameter distribution, stand basal area, volume yield, and above-ground biomass accumulation were assessed in three harvesting alternatives across three species groups. The results indicate a high degree of positive response to careful selective harvesting in lightly degraded, recovering miombo forests. Simulation systems compiled from experimentally based models seem promising as tools for research on stand dynamics and sustainable management alternatives in miombo woodlands.

Towards autonomous selective harvesting: A review of robot perception, robot design, motion planning and control

AbstractThis paper provides an overview of the current state‐of‐the‐art in selective harvesting robots (SHRs) and their potential for addressing the challenges of global food production. SHRs have the potential to increase productivity, reduce labor costs, and minimize wastage by selectively harvesting only ripe fruits and vegetables. The paper discusses the main components of SHRs, including perception, grasping, cutting, motion planning, and control. It also highlights the challenges in developing SHR technologies, particularly in the areas of robot design, motion planning, and control. The paper also discusses the potential benefits of integrating artificial intelligence and soft robots and data‐driven methods to enhance the performance and robustness of SHR systems. Finally, the paper identifies several open research questions in the field and highlights the need for further research and development efforts to advance SHR technologies to meet the challenges of global food production. Overall, this paper provides a starting point for researchers and practitioners interested in developing SHRs and highlights the need for more research in this field.

Modular autonomous strawberry picking robotic system

AbstractChallenges in strawberry picking made selective harvesting robotic technology very demanding. However, the selective harvesting of strawberries is a complicated robotic task forming a few scientific research questions. Most available solutions only deal with a specific picking scenario, for example, picking only a single variety of fruit in isolation. Nonetheless, most economically viable (e.g., high‐yielding and/or disease‐resistant) varieties of strawberry are grown in dense clusters. The current perception technology in such use cases is inefficient. In this work, we developed a novel system capable of harvesting strawberries with several unique features. These features allow the system to deal with very complex picking scenarios, for example, dense clusters. Our concept of a modular system makes our system reconfigurable to adapt to different picking scenarios. We designed, manufactured, and tested a patented picking head with 2.5‐degrees of freedom (two independent mechanisms and one dependent cutting system) capable of removing possible occlusions and harvesting the targeted strawberry without any contact with the fruit flesh to avoid damage and bruising. In addition, we developed a novel perception system to localize strawberries and detect their key points, picking points, and determine their ripeness. For this purpose, we introduced two new data sets. Finally, we tested the system in a commercial strawberry growing field and our research farm with three different strawberry varieties. The results show the effectiveness and reliability of the proposed system. The designed picking head was able to remove occlusions and harvest strawberries effectively. The perception system was able to detect and determine the ripeness of strawberries with 95% accuracy. In total, the system was able to harvest 87% of all detected strawberries with a success rate of 83% for all pluckable fruits. We also discuss a series of open research questions in the discussion section.

Influence of silvicultural practices in northern hardwood forests on a long-lived perennial herb, Trillium cernuum L.

Contemporary and predicted declines in tree species diversity and forest resilience have prompted renewed interest in even-aged systems and/or site preparation to overcome bottlenecks to tree recruitment or facilitate range expansion of future-adapted species. The impact of this intensification on the herbaceous layer in forests traditionally managed with uneven-aged systems, however, is unclear, especially for uncommon dispersal limited species with heterogenous distributions. We leveraged a large-scale experiment (the Northern Hardwood Silvicultural Experiment to Enhance Diversity) to investigate the response of Trillium cernuum L., a somewhat uncommon and heterogeneously distributed non-clonal herb in our study system, to a gradient of canopy removal and soil disturbance. We monitored 16 small populations from 2015 (the year prior to treatment) to 2019 (3-years post treatment). Our results suggest that initial population size and stage structure were inextricably coupled with T. cernuum response. Independent of treatment, T. cernuum abundance and flowering generally increased over time commensurate with initial population size. Moreover, our study highlights the confounding effect of deer herbivory, which increased significantly following treatment. Collectively, our findings suggest that T. cernuum populations were resilient to canopy disturbance associated with single-tree selection and shelterwood harvests and the levels of scarification applied as part of our study. Higher levels of site impact or other site preparation methods such as herbicides will likely have greater impacts and warrant further investigation. Our results also suggest that directly monitoring populations of interest may be necessary to quantify treatment effects for uncommon and/or heterogenous species that are missed with common plot-based sampling designs or of conservation concern.

Tea-YOLOv8s: A Tea Bud Detection Model Based on Deep Learning and Computer Vision.

Tea bud target detection is essential for mechanized selective harvesting. To address the challenges of low detection precision caused by the complex backgrounds of tea leaves, this paper introduces a novel model called Tea-YOLOv8s. First, multiple data augmentation techniques are employed to increase the amount of information in the images and improve their quality. Then, the Tea-YOLOv8s model combines deformable convolutions, attention mechanisms, and improved spatial pyramid pooling, thereby enhancing the model's ability to learn complex object invariance, reducing interference from irrelevant factors, and enabling multi-feature fusion, resulting in improved detection precision. Finally, the improved YOLOv8 model is compared with other models to validate the effectiveness of the proposed improvements. The research results demonstrate that the Tea-YOLOv8s model achieves a mean average precision of 88.27% and an inference time of 37.1 ms, with an increase in the parameters and calculation amount by 15.4 M and 17.5 G, respectively. In conclusion, although the proposed approach increases the model's parameters and calculation amount, it significantly improves various aspects compared to mainstream YOLO detection models and has the potential to be applied to tea buds picked by mechanization equipment.

Soil GHG dynamics after water level rise – Impacts of selection harvesting in peatland forests

Managed boreal peatlands are widespread and economically important, but they are a large source of greenhouse gases (GHGs). Peatland GHG emissions are related to soil water-table level (WT), which controls the vertical distribution of aerobic and anaerobic processes and, consequently, sinks and sources of GHGs in soils. On forested peatlands, selection harvesting reduces stand evapotranspiration and it has been suggested that the resulting WT rise decreases soil net emissions, while the tree growth is maintained. We monitored soil concentrations of CO2, CH4, N2O and O2 by depth down to 80 cm, and CO2 and CH4 fluxes from soil in two nutrient-rich Norway spruce dominated peatlands in Southern Finland to examine the responses of soil GHG dynamics to WT rise. Selection harvesting raised WT by 14 cm on both sites, on average, mean WTs of the monitoring period being 73 cm for unharvested control and 59 cm for selection harvest. All soil gas concentrations were associated with proximity to WT. Both CH4 and CO2 showed remarkable vertical concentration gradients, with high values in the deepest layer, likely due to slow gas transfer in wet peat. CH4 was efficiently consumed in peat layers near and above WT where it reached sub-atmospheric concentrations, indicating sustained oxidation of CH4 from both atmospheric and deeper soil origins also after harvesting. Based on soil gas concentration data, surface peat (top 25/30 cm layer) contributed most to the soil-atmosphere CO2 fluxes and harvesting slightly increased the CO2 source in deeper soil (below 45/50 cm), which could explain the small CO2 flux differences between treatments. N2O production occurred above WT, and it was unaffected by harvesting. Overall, the WT rise obtained with selection harvesting was not sufficient to reduce soil GHG emissions, but additional hydrological regulation would have been needed.

Ethnobotanical study of underutilized wild edible plants and threats to their long-term existence in Midakegn District, West Shewa Zone, Central Ethiopia

BackgroundEthiopia is endowed with much plant diversity. The insignificant number of studies on wild edible plants with their ethnobotanical perspectives indicated that this plant diversity comprised only hundreds of wild edible plants used to supplement food sources for the local community under different conditions. There still need to be further investigations throughout the country when compared to the total area and cultural diversity of the country. However, they are seriously under pressure due to different natural and human influences. Therefore, the study was conducted to document underutilized wild edible plants along with their associated indigenous knowledge and explore threats to them in Midakegn District.MethodsA questionnaire survey, semi-structured interviews, a market survey, score ranking, and focused group discussions were employed for data collection. Statistical analysis of ethnobotanical knowledge mean variation between different informant groups was computed by using one-way ANOVA in the IBM SPSS Statics version 24 package.ResultsA total of fifty underutilized wild edible plants belonging to 39 genera and 30 families were collected, recorded, and documented. The families Moraceae (four), Fabaceae, Flacourtaceae, Myrtaceae, Rosaceae, and Tiliaceae (each three) represented the highest number of species. It comprised shrubs (44%), trees (36%), herbs (18%), and epiphytes (2%). Fruits (62.3%) were found to be the most frequently used and mostly taken raw, fresh, or dried. These edible resources were consumed to supplement staple foods (67.3%), whereas 25% were used as emergency foods. The majority of species (96%) had multiple uses in addition to their edibility. A significantly higher (P < 0.05) number of underutilized wild edible plants were cited by males than females, by key informants than generals, elders than youngsters, illiterate than literate, and poorer than other wealth class groups of the community. Priority rankings indicate that agricultural expansion, fuel wood harvest, overgrazing, and selective harvesting are the most threatening factors to underutilized wild edible plants.ConclusionsFifty underutilized wild edible plants, along with their associated indigenous knowledge, were recorded. Local people utilize them for supplementing staple food, as emergency food, to get relief, trust, and chew during drought. But they are mainly threatened by different human activities in the study area.

How wide, how much? A framework for quantifying the economic and ecological outcomes of altering riparian width on agricultural land

Creating and managing riparian buffer zones (RBZs) is regarded as a global best-practice management strategy for maintaining and improving waterway health. Agricultural land often utilises RBZs as highly productive pasture, exposing waterways to increased inputs of nutrients, pollutants, and sediment, in addition to reducing carbon sequestration and habitat for native flora and fauna. This project developed a novel approach to the application of multisystem ecological and economic quantification models to the property-scale, at low cost and high speed. We developed a state-of-the-art dynamic geospatial interface to communicate these outputs when switching from pasture to revegetated riparian zone via planned restoration efforts. The tool was developed using the regional conditions of a south-east Australian catchment as a case study but is designed to be adaptable around globally using equivalent model inputs. Ecological and economic outcomes were determined using existing methods, including an agricultural land suitability analysis to quantify primary production, an estimation of carbon sequestration using historic vegetation datasets and GIS software analysis to determine spatial costings of revegetation and fencing. Economic outcomes are presented in raw values of pasture produced and carbon sequestered, and fencing and revegetation costs can be easily altered for enhanced usability and interoperability. This tool can provide property-specific data for almost 16,000 properties in a catchment area of over 130,000 km2 and 19,600 km of river length. Our results indicated that current financial incentives for revegetation rarely cover the cost of giving up pasture, but these costs may be compensated by social and ecological outcomes achieved over time. This method provides a novel way of informing alternative management approaches, such as incremental revegetation plans and the selective harvesting of timber from RBZ. The model provides an innovative framework for improved RBZ management and can be used to inform property-specific responses and guide discussion among stakeholders.

Size-selective harvesting alters biological traits of marine medaka (Oryzias melastigma)

Under long-term fishing pressure, the biological traits of many wild fish populations have changed. Such phenotypic changes include smaller in size and earlier age-at-maturation, strongly suggesting that fishing could induce rapid changes in the life-history traits of fish. However, whether extensive fishing will lead to genetic changes in fish, how they occur, and whether they are reversible still requires further research. In this study, we analyzed biological traits of marine medaka (Oryzias melastigma) subjected to 50% experimental harvest for 4 consecutive generations. This study adopted a factorial design with three size-selective harvesting strategies (large-, small-, and random-size selection) on groups either before or after maturation. We compared the growth, maturation, and early life stages of marine medaka for different harvesting strategies. The results showed that the mean lengths and mean weights in large-harvested populations significantly declined after 4 generations, whereas small-harvested populations did the opposite. Furthermore, selective harvesting of large individuals also led to earlier maturation, declining fecundity, declining hatching rate and increasing larval mortality. Importantly, compared to harvesting before maturation, harvesting after maturation could mitigate the effects of harvest on biological traits. This study provided experimental evidence for the impact of selective harvest on phenotypic evolution and contributed to the theoretical basis for sustainability in fisheries and fishery management.

Impacts of Diffuse Land-Use on Plant Diversity Patterns in the Miombo Woodlands of Western Zambia

Land use is known to influence the diversity of vascular plants in the Miombo woodlands. However, little is known about the interaction between soil and land use in herbaceous and woody species. We compared the diversity of vascular plants at the plot level (20 m × 50 m) and site level for three sites in the Miombo woodlands of western Zambia subject to different levels of intensity classes of diffuse land use (e.g., livestock herbivory and selective timber harvesting). For each of the sites, twenty plots were randomly selected for assessment of species composition of vascular plant species, indicators of land-use intensity, and soil chemistry per plot. We hypothesized that the site with the lowest human impact would have the highest richness and diversity of woody and herbaceous species. At the site level, we found that richness and diversity of woody species were unaffected by land-use intensity, whereas herbaceous species richness was higher for the protected site (28 species on average per 1000 m2) than the two other sites (23 and 21 species on average per 1000 m2). At the plot level, herbaceous species richness was positively associated with woodcutting and soil pH. We interpret the positive effect of woodcutting on herbaceous species richness as the effect of lower competition by the woody component for resources such as water, nutrients, and light. With regard to the absence of any effect of land-use intensity on the richness of woody species, we conclude that in our study areas selective timber harvesting may be at a sustainable level and might even have a positive effect on the diversity of the herbaceous layer.

Interim analysis examining the feasibility of incorporating laser microdissection enrichment of tumor specimens and reverse phase protein array analysis with next generation sequencing into a molecular tumor board.

e15068 Background: Since next generation sequencing (NGS) based profiling does not provide measures of protein abundance or activation state, clinical integration of reverse phase protein array (RPPA) with NGS could be useful for improving selection of targeted cancer therapy. We incorporated biopsy testing and proteogenomic analyses in an institutional Molecular Tumor Board (MTB) for cancer patients using CLIA-certified commercially available multi-omic platforms, including a commercially available CLIA RPPA functional protein drug target activation mapping platform. We present an interim analysis of our experience integrating functional phosphoprotein/protein based drug target activity data with NGS from 117 patients with metastatic solid tumors. Methods: Formalin-fixed, paraffin-embedded (FFPE) tumor biopsy specimens (n = 166) were obtained prospectively from patients as part of an IRB approved MTB. A representative H&amp;E-stained tissue section for each specimen was reviewed by a board-certified surgical pathologist. Specimens with sufficient total tumor cellularity to achieve protein lysate input requirements for RPPA were thin sectioned onto laser microdissection (LMD) membrane slides for selective harvest of tumor epithelium by LMD and RPPA analysis. In parallel, specimens from each case were also submitted for NGS analysis. The multi-omic data for each patient was reviewed by a panel of clinicians and scientists as part of the Inova Institutional MTB for clinical decision-making. Results: Patient tissue specimens (median = 1 per patient; range 1-5) were reviewed to assess feasibility of enriching tumor areas via LMD prior to RPPA analysis. Specimens from 64/117 patients were used for LMD, RPPA, and NGS. 48/117 patients were dropped due to inadequate tumor cellularity, patient death, or referral cases with inadequate specimen. At this time, 7/117 patients remained in the consenting-LMD-RPPA workflow. The median time from patient consent to RPPA analysis completion was 47.4 days. During this period, specimens were outside of the standard hospital-NGS workflow (ie, utilized for sectioning and review for LMD-RPPA) for ~10 days (median). Integrated review of the RPPA and NGS data by the MTB supported a clinical recommendation change for 34/64 patients (53%) overall, with some dependency by primary disease site. Clinical trial information: U20-11-4308.Conclusions: Incorporation of RPPA analysis of LMD enriched tumor samples with NGS was feasible in this pan-cancer cohort, with the mean time to results being less than 7 weeks. RPPA data provided additional treatment considerations for 59% of patients, the outcomes for whom continue to be monitored. [Table: see text]

Genetic rescue from protected areas is modulated by migration, hunting rate, and timing of harvest.

In terrestrial and marine ecosystems, migrants from protected areas may buffer the risk of harvest-induced evolutionary changes in exploited populations that face strong selective harvest pressures. Understanding the mechanisms favoring genetic rescue through migration could help ensure evolutionarily sustainable harvest outside protected areas and conserve genetic diversity inside those areas. We developed a stochastic individual-based metapopulation model to evaluate the potential for migration from protected areas to mitigate the evolutionary consequences of selective harvest. We parameterized the model with detailed data from individual monitoring of two populations of bighorn sheep subjected to trophy hunting. We tracked horn length through time in a large protected and a trophy-hunted populations connected through male breeding migrations. We quantified and compared declines in horn length and rescue potential under various combinations of migration rate, hunting rate in hunted areas and temporal overlap in timing of harvest and migrations, which affects the migrants' survival and chances to breed within exploited areas. Our simulations suggest that the effects of size-selective harvest on male horn length in hunted populations can be dampened or avoided if harvest pressure is low, migration rate is substantial, and migrants leaving protected areas have a low risk of being shot. Intense size-selective harvest impacts the phenotypic and genetic diversity in horn length, and population structure through changes in proportions of large-horned males, sex ratio and age structure. When hunting pressure is high and overlaps with male migrations, effects of selective removal also emerge in the protected population, so that instead of a genetic rescue of hunted populations, our model predicts undesirable effects inside protected areas. Our results stress the importance of a landscape approach to management, to promote genetic rescue from protected areas and limit ecological and evolutionary impacts of harvest on both harvested and protected populations.

Thinning, selective harvesting and mangrove protection forests: Lessons learned and recommendations from the Vietnamese Mekong Delta

To date, there have been controversies over the effects of thinning and selective harvesting (SH) on mangrove forests. Recently, thinning and SH regulations have been updated with limitation on intensity rates and the requirements for mangrove transplantation for mangrove protection forests of Vietnam. Crucial questions remain unanswered regarding whether upgraded thinning and SH have contributed to the mangrove loss, and whether they have resulted in longer-term negative effects on mangrove protection forests. We used the example of Kien Giang mangrove protection forest (KGMPF), Kien Giang, Vietnam as an appropriate case study to address the above questions. Modified Normalized Difference Water Index, Water Frequency Index, and Normalized Difference Vegetation Index were calculated to understand the effects of upgraded thinning and SH on mangrove protection within KGMPF. The findings reveal that upgraded thinning and SH did not contribute to the loss of mangrove forests in KGMPF between 2005 and 2015. Likewise, these two silvicultural techniques have not created any negative effects on vegetation cover in the districts between 2005 and 2015. In addition, these techniques have not resulted in longer-term effects on the vegetation cover in KGMPF, with the vegetation cover being gradually increased in all four districts between 2020 and 2022. The findings of this study provide solid evidence that the termination of upgraded thinning and SH in Vietnam, Kien Giang and wider region may not be required.

Contrasting demographic responses to size‐selective harvesting among neighbouring wild fish populations

Abstract Sustainable harvesting of wild populations relies on evidence‐based knowledge to predict harvesting outcomes for species and the ecosystems they inhabit. Although harvesting may elicit compensatory density‐dependence, it is generally size‐selective, which induces additional pressures that are challenging to forecast. Furthermore, responses to harvest may be population‐specific and whether generalizable patterns exist remains unclear. Taking advantage of Parks Canada's mandate to remove introduced brook trout Salvelinus fontinalis to restore alpine lakes in Canadian parks, we experimentally applied standardized size‐selective harvesting rates (the largest ~64% annually) for three consecutive summers in five populations with different initial size structures. Four unharvested populations were used as controls. At reduced densities, harvested and control populations exhibited similar density‐dependent increases in specific growth, juvenile survival and earlier maturation. However, size‐selective harvesting simultaneously induced changes to size and age structure that contrasted among harvested populations. Average body length decreased in three of five harvested populations, whereas it tended to increase in control populations over the 3 years. We also detected contrasting, population‐specific changes in body length variability and ultimately in length‐ and age‐at‐harvest in harvested populations but not controls. Overall, populations with smaller, more homogeneous body sizes, and living at high densities were most resilient to size‐selective harvesting, exhibiting the smallest change in size‐at‐age. In contrast, large‐bodied populations exhibited more substantial size‐structure changes following selective harvesting: large‐bodied populations experienced either stabilizing or disruptive pressures, when initial length variability was high or low, respectively. Synthesis and application. Our results show that within species, size‐selective harvesting inherently leads to more risk and uncertainty when harvesting populations with larger and more varied body sizes than smaller‐bodied populations with less range in body size. Our study supports prioritizing regulations that protect harvested populations with larger and more varied body sizes. Such a management strategy would reduce the likelihood of eliciting unpredictable or undesirable demographic changes to fish populations with these attributes.

The effect of age and sex selective harvest patterns for baleen whales

The taking of calves and females accompanied by calves is prohibited under the original and current forms of the Schedule of the International Whaling Commission. Proposed regulations under the Revised Management Scheme would reduce catch limits according to the proportion of females in the landings when females make up more than one-half of the landings. The implications of regulations on age, sex and reproductive status were explored by examining the relative impacts of baleen whale harvests with different age, sex and female reproductive status selectivity patterns using a matrix population model. The effects of 11 harvest patterns with varying selectivity for females and calves were measured by computing the fraction of the population that would have to be killed to reduce the growth rate of the population model to zero and the corresponding fraction of the population that would be landed (harvest fraction). The harvest impact per whale landed was measured for each selectivity pattern by expressing the harvest fraction as a percentage of the value of that fraction for a harvest random across age, sex and reproductive status. The harvest impacts per whale landed of the 11 patterns ranged from 64% greater to 29% lower than a random harvest. The patterns with the lowest harvest impact per whale landed were the pattern consistent with the IWC Schedule of prohibiting harvest of calves and females accompanied by calves, and the pattern of harvesting only calves. The harvest selectivity patterns which increased the vulnerability of females had the greatest impact. Relative to the IWC’s Revised Management Procedure, this increased female vulnerability was roughly compensated for by the decrease in catch limits as the proportion of females in the catches increased.

Large‐scale impacts of selective logging on canopy tree beta‐diversity in the Brazilian Amazon

Abstract Selective logging is one of the largest drivers of tropical forest degradation. While logged forests often retain high alpha‐diversity of tropical trees at local spatial scales, understanding how selective logging impacts tree beta‐diversity and community composition across far larger spatial scales remains a key unresolved question. We leverage large datasets of more than 155,000 adult trees over 35 cm DBH covering 3100 ha of Amazonian rainforest to inform simulations of selective logging harvests across a gradient of logging intensity (0–40 m3 ha−1). These simulations incorporate real world price data, account for all forest damage throughout the harvest process and assume preferential harvest of the most valuable stems. We use the simulations to assess how selective logging affects canopy tree beta‐diversity and composition across large spatial scales, whether nestedness or turnover of species best explains variation in communities across space, and how the spatial scale of sampling influences observed beta‐diversity effects. Selective logging had minimal impacts on beta‐diversity across the canopy tree community, but caused substantial subtractive heterogenization in community composition for larger trees, in particular very large trees over 110 cm DBH. Turnover is the dominant component of tree beta‐diversity in unlogged and logged forests. Increasing the spatial grain of sampling reduced the observed importance of logging in explaining patterns of beta‐diversity in very large tree communities. Synthesis and applications. Minimal impacts on tree beta‐diversity across large spatial scales points towards the retention of substantial conservation value in logged tropical forests. Strong subtractive heterogenization in very large trees indicates the breakdown of broad scale patterns of composition with potential negative consequences for recruitment processes, fauna reliant upon emergent trees, and other ecosystem functions and services. Avoiding large‐scale erosion of very large tree community composition in the Amazon requires stronger conservation policies, including enforced retention or maximum cutting diameters.

Hierarchically Templated Synthesis of 3D-Printed Crosslinked Cyclodextrins for Lycopene Harvesting.

Plants produce a wide range of bioactive phytochemicals, such as antioxidants and vitamins, which play crucial roles in aging prevention, inflammation reduction, and reducing the risk of cancer. Selectively harvesting these phytochemicals, such as lycopene, from tomatoes through the adsorption method is cost-effective and energy efficient. In this work, a templated synthesis of 3D-printed crosslinked cyclodextrin polymers featuring nanotubular structures for highly selective lycopene harvesting is reported. Polypseudorotaxanes formed by triethoxysilane-based telechelic polyethylene glycols and α-cyclodextrins (α-CDs) are designed as the template to (1) synthetically access urethane-based nanotubular structures at the molecular level, and (2) construct 3D-printed architectures with designed macroscale voids. The polypseudorotaxane hydrogels showed good rheological properties for direct ink writing, and the 3D-printed hydrogelswereconverted to the desired α-CD polymer network through a three-step postprinting transformation. The obtained urethane-crosslinked α-CD monoliths possess nanotubular structures and 3D-printed voids. They selectively adsorb lycopene from raw tomato juice, protecting lycopene from photo- or thermo-degradations. This work highlights the hierarchically templated synthesis approach in developing functional 3D-printing materials by connecting the bottom-up molecular assembly and synthesis with the top-down 3D architecture control and fabrication.

Outage Performance for NOMA-Based FSO-RF Systems With Transmit Antenna Selection and Nonlinear Energy Harvesting

In this article, we investigate the outage performance for a dual-hop free space optical-radio frequency communication system, in which a source node communicates with two users on a non-orthogonal multiple access basis via a single-aperture and multi-antenna relay, which can harvest energy from a power beacon under a nonlinear energy harvesting mode. In particular, two transmitting antenna selection (AS) criteria, namely, the random-maximum AS (RA-AS) and the minimum-maximum AS (IA-AS) schemes, are considered to improve the outage performance of the system. In addition, an adaptive power allocation algorithm, which allocates the power to each user according to the instantaneous channel power gain, is adopted for the RA-AS scheme. Considering the Gamma–Gamma distribution and the Rayleigh fading, the closed-form expressions of the outage probability for each user under both the RA-AS and IA-AS schemes are derived. Moreover, the Monte-Carlo simulation verifies the correctness of the theoretical derivations.