Search

In recent years, global demand for medicinal plants has surged due to their recognized therapeutic capacities in both traditional and modern medicine. The COVID-19 epidemic, skepticism regarding synthetic medications, and a desire for a natural supplement to address dietary deficiencies have collectively intensified demand. The therapeutic properties and commercial prospects of this group of plants are significant; nonetheless, the demand for wild species poses considerable risks to the integrity and sustainability of natural ecosystems. This commentary will address the necessity for sustainable harvesting of medicinal plants while preserving biodiversity and ecological balance. Overexploitation, habitat degradation, and insufficient management strategies increasingly threaten numerous medicinal plants, which are often keystone species fulfilling critical ecological functions. Unsustainable harvesting practices harm plant populations and ecological systems, especially slow-growing or region-specific species. Overexploitation and lack of information in local communities increase the risk of species extinction. A holistic approach that integrates scientific research, policy formulation, and community engagement is necessary to address these challenges. Promoting cultivation standards, biotechnological advancements, and traditional knowledge is crucial. Successful conservation initiatives necessitate the transdisciplinary collaboration of conservation scientists, policymakers, local people, and industry stakeholders. This strategy will assist in safeguarding ecological integrity and preserving these vital resources for future generations. [ABSTRACT FROM AUTHOR]

Cadra cautella (Walker) (Lepidoptera: Pyralidae) is a pest in barn, and its eggs are often utilized as an alternative prey or as hosts for mass production of insect predators and parasitoids. To aid in developing a mass-rearing system for C. castella, the suitability of using an artificial diet based on brown rice flour and whole brown rice was compared using the age-stage, 2-sex life table. Compared with those reared on brown rice, the insects reared on an artificial diet had a shorter preadult period (32.08 vs 37.38 d), higher fecundity (468.14 vs 356.20 eggs/female), greater intrinsic rate of increase (0.1509 vs 0.1145 d−1), and higher net reproductive rate (199.28 vs 103.52 offspring). Small populations were required to rear the moth on an artificial diet to achieve the same daily production of C. cautella. Still, the food expense was only 60.2% of that of C. cautella reared on brown rice. Approximately 99.44% of the eggs in each rearing procedure could be supplied as alternative prey for predators, with the remainder served to maintain the colonies for subsequent batches. Only eggs laid within 6 d would be utilized to ensure the high quality of alternative prey for the mass production of predacious bugs. Additionally, a multifunctional device was designed for moth rearing and egg collection, reducing labor input and minimizing health risks for workers coping with inhaled scales. To encourage the production of natural enemies, a cost-effective diet for maintaining a sustainable colony, and a system for daily egg-harvesting of alternative prey were proposed. [ABSTRACT FROM AUTHOR]

This study aimed to use the organic polymer, chitosan, as a flocculant for harvesting microalgae Chlorella. sp. Various polymer concentrations were tested. Within three min, 50 mg/L of chitosan showed the highest efficiency (98.9±0.5%), at pH 6.3, while the lowest efficiency (86.7±0.5%) was observed at pH 7.5. Harvesting efficiency in this study was chitosan concentration dependent. The present study showed that chitosan can be a promising and sustainable solution as an organic source and environmentally friendly flocculant. Additionally, it has excellent harvest productivity and requires minimum effort for quick outcomes.

In this paper, we discuss how a professor could have students, using rational and exponential functions, develop models for several different density-dependent populations based on characteristics of the species. Students would then need to choose an appropriate method from among three different analytic methods (find a solution, phase-line analysis, graphing approximate solutions) to analyse their models. We then discuss how to use aspects of a species' behaviour to choose an appropriate model from among the ones developed. Finally, we show how a professor could apply what students have learned to develop general principles for sustainable harvesting of such species. [ABSTRACT FROM AUTHOR]

This study aimed to use the organic polymer, chitosan, as a flocculant for harvesting microalgae Chlorella. sp. Various polymer concentrations were tested. Within three min, 50 mg/L of chitosan showed the highest efficiency (98.9±0.5%), at pH 6.3, while the lowest efficiency (86.7±0.5%) was observed at pH 7.5. Harvesting efficiency in this study was chitosan concentration dependent. The present study showed that chitosan can be a promising and sustainable solution as an organic source and environmentally friendly flocculant. Additionally, it has excellent harvest productivity and requires minimum effort for quick outcomes. [ABSTRACT FROM AUTHOR]

Purpose of the Study: This research investigates the use of plant species in Odisha's Shraddha rituals, aiming to highlight the interplay between cultural traditions and biodiversity conservation. It seeks to understand how these rituals contribute to the preservation of the region's botanical heritage and the broader environmental sustainability. Methodology: The study employed qualitative methods, including semi-structured interviews, discussions with key informants, and direct observations, across both rural and urban areas of Odisha's coastal districts. A total of 167 informants from diverse backgrounds participated, providing comprehensive insights into the rituals and their associated flora. The research also involved collecting plant specimens and photographic documentation to enrich the understanding of these practices. Main Findings: Thirty-nine plant species across 24 families, crucial to the Shraddha rituals, were identified. Notable species like Areca catechu and Cocos nucifera emerged as symbols of the spiritual-nature bond in Odia culture. The study uncovers challenges such as overharvesting and habitat destruction, emphasizing the urgent need for sustainable harvesting practices and biodiversity conservation. Applications of this Study: The findings are instrumental for cultural preservation, environmental conservation, and sustainable resource management. They provide a framework for local communities and religious leaders to engage in sustainable practices and for conservation bodies to develop strategies that balance cultural traditions with ecological preservation. Novelty/Originality: This research is unique in its ethnobotanical approach to exploring the role of religious rituals in environmental conservation. Integrating cultural anthropology with botanical science offers new insights into how traditional practices can support biodiversity preservation. Its comprehensive analysis across both rural and urban settings in Odisha adds depth and relevance to the understanding of these rituals in contemporary society, making it a novel contribution to the field.

Population responses to repeated environmental or anthropogenic disturbances depend on complicated interactions between the disturbance regime, population structure, and differential stage susceptibility. Using a matrix modeling approach, we develop a methodological framework to explore how the interplay of these factors impacts critical population thresholds. To illustrate the wide applicability of this approach, we present two case studies pertaining to agroecosystems and conservation science. We apply sensitivity analysis to the two case studies to examine how population and disturbance properties affect these thresholds. Contrasting outcomes between these two applications, including differences in how factors such as disturbance intensity and pre‐disturbance population distributions impact population responses, highlight the importance of accounting for demographic features when performing ecological risk assessments. [ABSTRACT FROM AUTHOR]

The study demonstrates the feasibility to scale-up (20 L) the wild-type and improved phenotypes of long chain fatty acids (LCFA) producing Micractinium sp. GA001. The improved phenotypes were achieved using flow cytometry-based adaptive evolution strategy under nitrogen stressed condition. Improved phenotypes of Micractinium sp. GA001 were scale-up to 20 L and compared to the wild-type. Results confer adequate performance in microalgal growth and cellular development. GA001 cell size was increased from 5.4 ± 0.16 to 6.14 ± 0.2 μm during scale-up. An increase in cell-surface-volume in improved phenotypes of GA001 facilitated spacious environment inside the cell for the efficient biosynthesis and accumulation of intracellular components especially photosynthetic chloroplast. The finding was supported by analyses that were showing an increase in the chlorophyll content in the improved phenotypes throughout the scale-up period. The biomass and lipid productivity of improved phenotypes in scale-up experiments were consistent with flask cultivation thus ecological stability of the improved phenotypes was confirmed. Also, a simple, cost-effective, and sustainable harvesting methodology was established using the natural bioflocculant chitosan. Altogether, we can conclude that there is potent scope for further scale-up in different set-ups with promising biomass and lipid productivity of LCFA producing GA001 in long run. [ABSTRACT FROM AUTHOR]

Garcinia kola, known as bitter kola, is a promising multipurpose fruit tree from tropical forests in West and Central Africa. Despite the popularity of the species in folk medicine, very little is known about its management and commercialization. This knowledge might prevent unsustainable collection, overexploitation, and threats to its wild population. Thus, we investigated markets and identified three collection areas in Cameroon among 72 vendors selling bitter kola products. Among 122 purposively selected farmers, we analyzed the uses, management, and economic value of G. kola for rural households in these locations. We also documented the morphological characteristics of 227 trees utilized by interviewees. Knowledge of the medicinal properties of bitter kola was similar among all actors involved in the collection and commercialization of G. kola. However, the selected regions differed in management, plant part preferences, harvesting practices, and morphological characteristics. We suggest applying sustainable harvesting practices to support the conservation of wild-growing trees, promoting participatory domestication of the species, switching from bark collection to seed gathering, and linking farmers with promising and profitable markets. [ABSTRACT FROM AUTHOR]

Syagrus coronata (Mart.) Becc. (Arecaceae), known as licuri, is a palm tree widely distributed throughout the Brazilian semi-arid, being currently vulnerable to extinction. Its fruits are exploited by both humans and animals, representing high sociocultural, economic, and ecological relevance. This palm tree is found in areas under different management intensity and land use; therefore, both medium and long-term ecological monitoring programs are essential to verify the effects of anthropogenic disturbances on the dynamic of their populations. Information on population structure and growth (λ) from 2018 to 2021 was obtained in 40 plots of 20 × 20 m (1.6 ha). Population matrix models based on five life stages (seedling, sapling, juvenile, immature adult, and reproductive adults) were obtained, in addition to information on fruit productivity and harvesting intensity. Individuals from the seedling stage predominated in both pasture and natural habitats. The populations from two habitats were stable (Pasture λ = 1.00 and Natural λ = 1.01); however, no transition occurred from earlier up to later stages. The population in the pasture was characterized by a low transition rate (recruitment of juveniles onwards), caused mainly by the pressure exerted by cattle. Our results suggest that the adult reproductive and seedling stages are the most important for the survival and growth of the populations. Harvest intensity had no effect on population growth, and only 16.65 % of the fruit annual production was collected. Therefore, fruit harvesting is sustainable, but the type of pasture management might compromise the future of the population. Management strategies ought to reduce the pressure exerted by livestock to increase the transition between stages and maintain the S. coronata populations over several years. [ABSTRACT FROM AUTHOR]

Plant reproductive biology encompasses the study of sexual and asexual reproduction, as well as morphological, physiological, ecological, and genetic aspects influencing these processes. Management can influence reproduction of plants and associated attributes. For economically and culturally important species, it is known that exudates affect biomass of reproductive parts, but limited information is available on how reproductive biology is affected by harvest of exudates. This study reviews the effects of resins extraction in economic and culturally important species of Burseraceae. We conducted a systematic review on studies of floral biology, management, propagation and germination, resource allocation and pollination, hypothesizing that the extraction of exudates negatively impacts the reproductive biology of these plants by altering their mating system, pollination, and reproductive success as a consequence of resource reallocation. We identified that dioecy is the most frequent mating system in Burseraceae plants, and the extraction of exudates negatively affects the reproductive success of the species utilized, since it is related to a decrease in the number of flowers, fruits, and seeds, as well as in the percentage of viability and seed germination. Our review suggests the relevance of conducting studies on the ecophysiological effects of management on resiniferous species. Furthermore, it highlights the difficulty of detecting clear patterns, specific studies should be carried out to corroborate the hypothesis derived from this review. We propose specific strategies that better explore the effect of human management and exudate extraction techniques on vital processes such as germination, development, growth, reproduction, and pollination, in species that are used for this purpose.

Dispersal of organisms between patches is a common phenomenon in ecology and plays an important role in predator–prey population dynamics. We propose a nonsmooth Filippov predator–prey model in a two-patch environment characterized by a generalist predator-driven intermittent refuge protection of an apprehensive prey along with a balanced dispersal of the prey between refuge and nonrefuge areas. By employing qualitative techniques of nonsmooth dynamical systems, we see that the switching surface is a repeller whenever the interior equilibria are virtual, causing long-term population fluctuations. We find that the level of prey vigilance and the rate of prey dispersal play pivotal roles in the total harvesting yield. We observe that a sustainable high harvesting yield is possible when the prey is less vigilant and obtain the harvesting efforts for maximum sustainable total yield (MSTY). We further modify the model by considering a continuous threshold predator-driven prey dispersal and show that the model exhibits a Hopf bifurcation when the level of prey vigilance exceeds some critical threshold value. By comparing the dynamics of the two models we see that for a sustainable high harvesting yield of the system with continuous threshold dispersal, the prey needs to be highly vigilant compared to that of the system with intermittent dispersal of the prey. Further, we find numerically that the estimated MSTY from both models remains the same. [ABSTRACT FROM AUTHOR]

Abstract The unique Himalayan ecosystems are repositories to the wild populations of diverse flora and fauna. The high value medicinal and aromatic plant species (MAPs) are an example of the same. Since time immemorial, these MAPs have been traditionally used by the local inhabitants and have eventually developed a high market value all over the world. Increasing market demand engenders over-extraction of species, unsustainable collection further catalyses decline in wild populations. The current communication raises high conservation concern on the rapid population decline of Fritillaria cirrhosa D.Don in the Western Himalaya. Harvested and traded with a new trade name i.e., ‘Jangli lehsun’ probably to disguise common Allium species, the species is facing tremendous decline in wild populations due to its illegal harvesting and trade in Himachal Pradesh. Further, F. cirrhosa faces threat due to unorganized, over-extraction, unsustainable and premature harvesting of the bulbs, coupled with illegal hidden markets functioning parallelly. Considering that this valuable species is under multiple threats being a medicinally important plant, priority should be given for its conservation through in-situ such as identification of medicinal plant conservation areas and ex-situ methods for its propagation and multiplication. Further, to ensure the long-term conservation of Fritillaria cirrhosa, prioritized conservation strategies such as strengthening of the Biodiversity Management Committees, capacity building through awareness programs for the key stakeholders and sustainable harvesting would be the practical solution.

[Display omitted] • Wild food plants (WFP) are helpful for maintaining the food and socioeconomic security of harvesting populations. • Food products with names associated with WFP lower consumer expectations regarding taste and appropriateness. • Food products with names associated with forest environments lower consumer expectations regarding taste and appropriateness. • This marketing strategies to popularize WFP can include associating the product with a conventional plant to evoke familiarity; This marketing strategies to popularize WFP can while keeping its original name to contribute to cultural valuation. • Empowerment programs for harvesters can assist in sustainable development and ensure the biocultural conservation of WFP. Despite the high global richness of food plants, only a small portion is effectively used as food by human populations. Although most wild food plants (WFPs) are underutilized as food, they can contribute to food security and biocultural conservation through sustainable management. The goal of this research was to identify the best terminological presentation of a novel food product and to understand the factors that influence the expectations concerning products made with WFPs. This research was conducted using an online questionnaire, with a final national sample of 724 people. The participants answered questions about their socioeconomic profile, food neophobia, previous knowledge, and expectations regarding the taste and appropriateness of native fruit juices. The questions were randomized, so that a person would not receive the same picture or product name more than once. The results show that taste expectancy decreases in relation to products associated with WFP names and forest environments. Food neophobia is the variable that influences expectations the most. To ensure biocultural conservation and cultural valuation, WFP popularization programs should maintain the original (popular) name of the species. However, to help more distant consumers develop familiarity, the flavor, shape, color, or texture of these products can be associated with those of conventional plants. [ABSTRACT FROM AUTHOR]

With a world population estimated at 10 billion people by 2050, the challenge to secure healthy and safe food is evident. Seaweed is a potential answer to this challenge. Expanding the use of seaweed in food systems requires an emphasis on safe practices to avoid adverse human health effects after consumption and irreversible damage to marine ecosystems. This study aims to evaluate relevant food safety and environmental safety hazards, monitoring measures, and mitigation strategies in the seaweed sector. For this study, a literature review, survey (n = 36), and interviews (n = 12) were conducted to identify hazards. The review and interviews aimed at pinpointing monitoring measures and mitigation strategies applied, while the survey revealed data gaps and further actions needed for the sector. Relevant food safety hazards include (inorganic) arsenic, iodine, and heavy metals, among others, such as pathogenic bacteria, while environmental hazards include environmental pathogens and parasites introduced into the ecosystem by domesticated seaweed, among others. Measures applied aim at preventing or mitigating hazards through good hygienic or manufacturing practices, food safety procedures or protocols, or pre-site farm selection. Although the future needs of the seaweed sector vary, for some, harmonized advice and protocols that align with a changing food system and hazard knowledge development as well as information on the benefits of seaweed and regulating climate and water quality may help. [ABSTRACT FROM AUTHOR]

There is growing concern in the UK that available base cation pools in soil are declining due to the combined effects of acid deposition and forest harvesting. To help inform the issue, elemental mass balances for calcium (Ca), magnesium (Mg) and potassium (K) were calculated using more than 10-years (10–24 years) of data from the UK's ICP Forest Intensive Monitoring Network (Level II) of plots, covering a range of soil types and three tree species—oak, Scots pine and Sitka spruce. Out of the ten sites investigated, small negative Ca balances were observed at three sites and negative K balances on two sites, all on acid geology and nutrient poor soils, which were previously heavily acidified due to acid deposition. There is sufficient Ca and K in the soil exchangeable pool to sustain forest growth on these sites, however, if the present rate of Ca and K loss continues forest health and productivity are likely to be threatened within a few forest rotations. Magnesium showed a positive balance at all but one site, partly sustained by marine deposition. Base cation budgets were significantly (p < 0.01) positively related to soil exchangeable cations and soil base saturation status. Six of the sites showed an increasingly statistically significant positive cation balance with time, attributed to a decline in leaching linked to recovery from acidification. This included the three sites with negative Ca balance, although Ca remained in deficit. One site (Alice Holt) exhibited a decreasing cation balance, driven by a continued significant decline in base cation deposition thought to be related to pollutant emission control. The results were used to simulate the impact of different forest biomass harvesting scenarios involving the removal of brown (extracted after needle drop) or green (extracted before needle drop) brash. Podzols and deep peats were found to be the most vulnerable to brash harvesting causing Ca and K imbalance, but problems also occurred on brown earths. Impacts were greatest for the extraction of green brash from higher productivity stands. Base cation balance calculations remain highly uncertain due to the restricted nature of available measurements and wide variation of some estimates, particularly inputs from mineral weathering. More data are required to check and improve model predictions to better guide forest harvesting practice and ensure sustainable forest management. [ABSTRACT FROM AUTHOR]

Copyright of Ecosistemas y Recursos Agropecuarios is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Studies on population dynamics are helpful for understanding the factors determining population development and predicting the effects of disturbances, such as harvesting of plant species. In an investigation of the demography of a terrestrial medicinal orchid known as Crepidium acuminatum, the effects of harvesting on its population dynamics were recorded. Data on recruitment, growth and survival were collected in three populations of C. acuminatum over a 6-year period (2012–2017) in central Nepal. A matrix modeling method was used to determine the effect of different harvesting regimes on the population growth and survival of this species. Population growth rates (λ) of unharvested populations were relatively similar and stable in different years of the study. Harvesting significantly reduced λ. The results of this study indicate that the sustainable survival of a population that is subject to harvesting can only occur when it is either selective (only flowering individuals or only small amounts of vegetative individuals) or rotational (once every 3–5 or more years). This study demonstrates the necessity of using a sustainable method when harvesting natural populations. Our results are useful for developing efficient management strategies for this species. As each species has a different biology, similar studies are needed for other rare and/or economically important species in the Himalayan region and in other understudied parts of the world.

The ecological effects of harvesting from wild populations are often uncertain, especially since the sensitivity of populations to harvesting can vary across species' geographical ranges. In the Cape Floristic Region (CFR, South Africa) biodiversity hotspot, wildflower harvesting is widespread and economically important, providing an income to many rural communities. However, with very few species studied to date, and without considering range‐wide sensitivity to harvesting, there is limited information available to ensure the sustainability of wildflower harvesting.We studied geographical variation in sensitivity to wildflower harvesting for 26 Proteaceae shrubs with fire‐driven life cycles using population viability analyses. We developed stochastic, density‐dependent population models that were parameterised from individual demographic rates (adult fecundity, seedling recruitment and adult fire survival) and local environmental conditions across the geographical ranges of the study species. We then simulated the effects of harvesting on populations in different environments across species ranges. Our model simulations predicted extinction risk per population, and we derived extinction probabilities over 100 years in response to different harvesting regimes. We used these population‐level extinction probabilities to quantify inter‐ and intraspecific variation in sensitivity to wildflower harvesting, and to explore how geographical variation in sensitivity depends on environmental conditions (climate, soil fertility and fire disturbance).We detected considerable inter‐ and intraspecific variation in sensitivity to wildflower harvesting for the 26 study species. This held for both 'nonsprouters' and 'resprouters' (species with low and high fire persistence ability, respectively). Intraspecific variation in sensitivity to harvesting showed varying geographical patterns and associated with environmental variation. Notably, sensitivity was high towards range edges and at the climatic extremes of species ranges respectively.Synthesis and applications. We show the importance of combining spatial demographic data, density‐dependent population dynamics and environmental variation when assessing sensitivity to harvesting across species' geographical ranges. Our findings caution against the application of general harvesting guidelines irrespective of species, geographical location or local environmental conditions. Our range‐wide population viability analyses provide insights for developing species‐specific, spatially nuanced guidelines for conservation management. Our approach also identifies species and areas to prioritise for monitoring to prevent the overexploitation of harvested species. [ABSTRACT FROM AUTHOR]

This paper proposes a simple and direct method to provide reliable approximations of the net present value (NPV) and the perpetual value (PV) of sustainable timber harvests from a monospecific uneven-aged forest based on dimensionless numbers. In addition, two new dimensionless numbers ρNPV and ρPV are introduced. These use the NPV or PV derived from the sale of timber throughout a harvest cycle, plus the final stocking value (as numerator), and the fair value of standing timber under IAS 41 (as denominator). They can be interpreted as economic performance indicators for forest management, inspired by the return on assets accounting concept, showing how profitable the forest is, relative to its total value, with sustainability and stability criteria. Those approximations to the variables NPV, PV, ρNPV and ρPV, were obtained under conditions of stable equilibrium from a matrix model. In order to exemplify and test the results, the model used data from uneven-aged managed Pinus nigra stands, considering three levels of tree diameter growth, six levels of basal area and 33 levels of recruitment, creating a total of 594 planning scenarios. Furthermore, the study revealed the existence of strong linear correlations between those variables and a dimensionless number.

Ebony wood, the black heartwood of trees in the genus Diospyros , is a high-value commodity of many Pacific Islands. The revenue earned from the sale of ebony carvings is important for many low-income rural communities, resulting in high harvesting pressure and reported declines of ebony-producing species. This study investigates the impact of ebony wood harvesting on species of Diospyros on Vangunu Island, Western Solomon Islands. Diospyros samoensis , locally known as 'rihe', was the main source of ebony wood, with D. vera occasionally harvested but producing poorer quality wood. For D. samoensis , we investigated the existing ethnobotanical knowledge and harvesting dynamics using questionnaires and surveyed 11 populations using five 15 × 15 m plots. Although D. samoensis was common throughout the study area, trees with harvestable ebony heartwood were considered rare. The sale of ebony carvings contributed substantially to the livelihood of carvers. Harvesting practices cause considerable damage to the stem and appeared to alter population structure, with fewer seedlings found in stands with higher harvesting intensities (r = −0.704, P = 0.008). Therefore, populations of D. samoensis appear to be negatively impacted by current harvesting practices, which should be modified to (1) cause less damage to individual trees and populations, and (2) protect larger and older trees to help regeneration. Therefore, the increasing rarity of ebony heartwood in the Pacific may not equate to dangerous declines in Diospyros species and implementing low-impact harvesting practices could help improve the health and long-term persistence of Diospyros populations. Ebony heartwood of some trees is used to produce high-value carvings in the Pacific, with supplies reportedly declining. While the source species, Diospyros samoensis , is not currently threatened with extirpation, poor harvesting practices cause severe damage to trees and reduce regeneration. Scarce ebony heartwood supplies do not equate to rarity of D. samoensis but implementing sustainable harvesting practices could avoid long-term population declines. [ABSTRACT FROM AUTHOR]

As a pioneering work in the field of domestication of Pyrenacantha volubilis Wight, an anti-cancer drug (camptothecin) yielding plant, this study identifies superior seed sources of southern peninsular India for various parameters related to its growth and yield. The experiment was set up following the common garden experiment protocol in Completely Randomised Design. Laboratory extraction of camptothecin from whole seeds was carried out using High Performance Liquid Chromatography. Whereas seeds from Kizhoor population were the heaviest (test weight of 171.5 g), seedlings obtained by sowing the seeds from Villiampakkam population performed better in terms of total yield per plant (5.25 g dry weight) as well as total camptothecin yield per hectare (223.125 g). Almost three times variation was observed in the experiment between the poorest and the best performing populations. We attempt to discuss the potential for domestication, large-scale planting and sustainable harvesting of this promising and versatile new cash crop. [ABSTRACT FROM AUTHOR]

This article develops and implements a stochastic optimal control approach to value renewable natural resources in the case of Marine Fisheries. The model includes two sources of uncertainty: the resource biomass and the price of fish, and it can be used by fisheries and regulators to optimally adapt their harvesting strategy to changing conditions in these stochastic variables. The model also features realistic operational cash flows. Using publicly available data on the British Columbia halibut fishery, the required parameters are estimated and the model is solved. The results indicate that price uncertainty is especially important in valuing fisheries and determining the optimal harvesting policy. [ABSTRACT FROM AUTHOR]

In standard models of spatial harvesting, a resource is distributed over a continuous domain with an agent who may harvest everywhere all the time. For some cases though (e.g., fruits, mushrooms, algae), it is more realistic to assume that the resource is located at a fixed point within that domain so that an agent has to travel in order to be able to harvest. This creates a combined travelling–and–harvesting problem where slower travel implies a lower travelling cost and, due to a later arrival, a higher abundance of the resource at the beginning of the harvesting period; this, though, has to be traded off against less time left for harvesting, given a fixed planning horizon. Possible bounds on the controls render the problem even more intricate. We scrutinise this bioeconomic setting using a two-stage optimal control approach, and find that the agent economises on the travelling cost and thus avoids to arrive at the location of the resource too early. More specifically, the agent adjusts the travelling time so as to be able to harvest with maximum intensity at the beginning and the end of the harvesting period, but may also find it optimal to harvest at a sustainable level, where the harvesting and the growth rate of the stock coincide, in an intermediate time interval. [ABSTRACT FROM AUTHOR]

Sea urchins act as a keystone herbivore in marine coastal ecosystems, regulating macrophyte density, which offers refuge for multiple species. In the Mediterranean Sea, both the sea urchin Paracentrotus lividus and fish preying on it are highly valuable target species for artisanal fisheries. As a consequence of the interactions between fish, sea urchins and macrophyte, fishing leads to trophic disorders with detrimental consequences for biodiversity and fisheries. In Sardinia (Western Mediterranean Sea), regulations for sea urchin harvesting have been in place since the mid 90s. However, given the important ecological role of P. lividus, the single-species fishery management may fail to take into account important ecosystem interactions. Hence, a deeper understanding of population dynamics, their dependance on environmental constraints and multispecies interactions may help to achieve long-term sustainable use of this resource. This work aims to highlight how sea urchin population structure varies spatially in relation to local environmental constraints and species interactions, with implications for their management. The study area (Sinis Peninsula, West Sardinia, Italy) that includes a Marine Reserve was divided into five sectors. These display combinations of the environmental constraints influencing sea urchin population dynamics, namely type of habitat (calcareous rock, granite, basalt, patchy and continuous meadows of Posidonia oceanica), average bottom current speed and predatory fish abundance. Size-frequency distribution of sea urchins under commercial size (

There is growing concern in the UK that available base cation pools in soil are declining due to the combined effects of acid deposition and forest harvesting. To help inform the issue, elemental mass balances for calcium (Ca), magnesium (Mg) and potassium (K) were calculated using more than 10-years (10–24 years) of data from the UK’s ICP Forest Intensive Monitoring Network (Level II) of plots, covering a range of soil types and three tree species—oak, Scots pine and Sitka spruce. Out of the ten sites investigated, small negative Ca balances were observed at three sites and negative K balances on two sites, all on acid geology and nutrient poor soils, which were previously heavily acidified due to acid deposition. There is sufficient Ca and K in the soil exchangeable pool to sustain forest growth on these sites, however, if the present rate of Ca and K loss continues forest health and productivity are likely to be threatened within a few forest rotations. Magnesium showed a positive balance at all but one site, partly sustained by marine deposition. Base cation budgets were significantly (p < 0.01) positively related to soil exchangeable cations and soil base saturation status. Six of the sites showed an increasingly statistically significant positive cation balance with time, attributed to a decline in leaching linked to recovery from acidification. This included the three sites with negative Ca balance, although Ca remained in deficit. One site (Alice Holt) exhibited a decreasing cation balance, driven by a continued significant decline in base cation deposition thought to be related to pollutant emission control. The results were used to simulate the impact of different forest biomass harvesting scenarios involving the removal of brown (extracted after needle drop) or green (extracted before needle drop) brash. Podzols and deep peats were found to be the most vulnerable to brash harvesting causing Ca and K imbalance, but problems also occurred on brown earths. Impacts were greatest for the extraction of green brash from higher productivity stands. Base cation balance calculations remain highly uncertain due to the restricted nature of available measurements and wide variation of some estimates, particularly inputs from mineral weathering. More data are required to check and improve model predictions to better guide forest harvesting practice and ensure sustainable forest management.

The monitoring of ecosystems and the spread of information concerning their state among human stakeholders is often a lengthy process. The importance of mutual feedbacks between socioeconomic and ecological dynamics is being increasingly recognised in recent studies, but it is generally assumed that the feedback from the environment is instantaneous, ignoring any delay in the spread of ecosystem knowledge and the resulting potential for system stability loss. On the other hand, human actors rarely make purely myopic socioeconomic decisions as is often assumed. Rather, they show a degree of foresight for future utility which may have an opposing, stabilising effect to any delay in knowledge. In this paper, we consider a generic resource-harvester model with delayed ecosystem knowledge and predictive behaviour by the harvesters. We show that delays in the spread of information about the resource level can destabilise the bioeconomic equilibrium in the system and induce harvesting cycles or the collapse of the resource. Sufficiently farsighted prediction by the harvesters can stabilise the system, provided the delay is not too long. However, if the time horizon of prediction is too long relative to the timescale of resource growth, prediction can be destabilising even in the absence of delay. The results imply that effective monitoring of ecosystems and fast dissemination of the results are necessary for their sustainable use and that efforts to promote appropriate foresight among ecosystem users on the personal and institutional level would be beneficial to the stability of coupled socioeconomic-ecological systems. [ABSTRACT FROM AUTHOR]

This paper focuses upon the role that science-based interventions allied to effective regulatory regimes can play in reducing the threat posed by inappropriate harvesting of wild flora. A Vulnerability Index (VI) has been developed for 150 natural fynbos species that exist on South Africa's Agulhas Plain, where intensive wildflower harvesting occurs. The methodology underpinning the generation of the VI is outlined and justified in this paper. The VI comprises a range of characteristics relating to species distribution and biology that are likely to influence vulnerability to harvesting. The VI is proving to be an important tool for regulating the harvesting of wild fynbos and maintaining the resilience of natural ecosystems threatened by climate change. Furthermore, economic development and livelihood stability are promoted by protecting the resource base of marketable species. The paper discusses issues that have arisen relating to the application and rollout of the VI in practice. [ABSTRACT FROM AUTHOR]

Seaweeds such as Ascophyllum nodosum are essential components of coastal ecosystems, being frequently relevant both ecologically and economically. The current increasing demand for seaweed biomass must be compatible with sustainable management practices of these resources. This study aims to provide supporting evidence for the establishment of management plans for "edge populations" (at their distributional limits) with commercial interest using, as a model, the southernmost population of A. nodosum in Europe (which occurs on the northern coast of Portugal). In this study, standing stock, biomass renewal and seasonal and spatial patterns of occurrence of this Ascophyllum unexploited population were assessed in order to evaluate harvesting potential. A total of 16 patchily distributed and variable sized beds, covering an area of 112,126 m2, were delimited during late summer/autumn of 2016, providing a standing stock of 30,952.12 kgdw. The abundance of these populations was stable over time (2005–2010), although small-scale spatial variations and changes in individual biomass due to seasonal loss could be identified. However, the potential biomass renewal as estimated for this whole population was 290.3 kgdw year−1, representing only 0.94% of the calculated standing stock. Based on these results, the importance of considering the population's renewal potential is highlighted in addition to individual phenotypic traits when managing harvesting. Specifically, given the vulnerability and ecological relevance of the studied population, the recommendation herein is to avoid harvesting of this species at its southernmost location in Europe. [ABSTRACT FROM AUTHOR]

This paper proposes a simple and direct method to provide reliable approximations of the net present value (NPV) and the perpetual value (PV) of sustainable timber harvests from a monospecific uneven-aged forest based on dimensionless numbers. In addition, two new dimensionless numbers ρNPV and ρPV are introduced. These use the NPV or PV derived from the sale of timber throughout a harvest cycle, plus the final stocking value (as numerator), and the fair value of standing timber under IAS 41 (as denominator). They can be interpreted as economic performance indicators for forest management, inspired by the return on assets accounting concept, showing how profitable the forest is, relative to its total value, with sustainability and stability criteria. Those approximations to the variables NPV, PV, ρNPV and ρPV, were obtained under conditions of stable equilibrium from a matrix model. In order to exemplify and test the results, the model used data from uneven-aged managed Pinus nigra stands, considering three levels of tree diameter growth, six levels of basal area and 33 levels of recruitment, creating a total of 594 planning scenarios. Furthermore, the study revealed the existence of strong linear correlations between those variables and a dimensionless number. [ABSTRACT FROM AUTHOR]

Carposina sasakii Matsumura is one of the most destructive fruit-boring pests of pome and stone fruit trees in eastern Asia. Because larvae complete their development inside a single fruit, larval density per fruit is a critical factor in their survival, development, and fecundity. The effect of larval density was examined to determine the ideal density for devising an economic and sustainable mass-rearing system for harvesting of C. sasakii. Mass production of insects of the same age of a specific stage is not only important in biological control, but also in pheromone extraction, culturing of entomopathogenic nematodes and fungi, etc. Life history data for six larval densities (1–5, 6–10, 11–15, 16–20, 21–30, and 31–40 larvae/apple) were collected at 25.5 ± 0.5°C, 75.0 ± 5.0% RH, and a photoperiod of 15:9 (L: D) h. Data were analyzed using the age-stage, two-sex life table. The results showed that the highest preadult survival rate (42.00%), fecundity (104.70 eggs), and population parameters (intrinsic rate of increase r = 0.0718 d−1, net reproductive rate R 0 = 23.03 eggs, and finite rate of increase λ = 1.0744 d−1) were observed at a density of 1–5 larvae/apple. However, when the rearing costs and production rate were considered, the density of 16–20 larvae/apple was the most economical for mass-rearing C. sasakii in order to achieve a daily harvest rate of 1,000 pupae (from 273 apples per day). To ensure the sustainability of the mass-rearing system, we included the life table variability in the harvesting strategy. [ABSTRACT FROM AUTHOR]

ABSTRACT We assess the impact of climate change on the geographic distribution and productivity of Euterpe oleracea (Arecaceae), commonly called açaí. To construct the ecological niche model of E. oleracea, we used 95 points of occurrence, five bioclimatic variables in current and future climate scenarios and Maxent software. The Akaike Information Criteria (AIC) was used to rank the ability of the models (considering ecological, socioeconomic and spatial variables) to explain the variation in productivity of E. oleracea among 200 municipalities. The maps showed that regions with higher environmental suitability for E. oleracea were concentrated in northern and northeastern Brazil, which was similar to the spatial pattern of productivity data of E. oleracea. Future climate conditions tend to promote an increase in the geographical distribution of this species, even though the new regions are in the arch of Amazon deforestation. Only space and the environmental suitability (indicated by the ecological niche model) were important for explaining the productivity of E. oleracea. That is, municipalities that are more productive are located in more suitable environmental regions. Therefore, it is important to use niche models to explain demographic changes and to estimate species demographic attributes.

The increased demand for natural products from wild aromatic and medicinal plants has stimulated several research projects focusing on phytochemistry, ethnobotany, pharmacognosy and many other sub-disciplines related to medicine and pharmacy or cosmetology and chemical industry in general. Morocco is one of the richest Mediterranean countries whose flora is well known and many of its plant resources and products very demanded by consumers and manufacturers but there is an urgent need to deal with wild medicinal and aromatic plants namely found on public lands. In this study, we attempt to identify and assess the wild species to overharvesting especially those in forest lands and then identify priority ones. A rapid vulnerability assessment approach was applied to 182 species inventoried referring to its biological, ecological and chorological criteria then combined to trade data. We obtained three groups of MAP species depending on its vulnerability ranked from high to very low vulnerability and their availability at national level. A list of 25 priority species was sorted on its economic value for export and then only the most representative ones within each region was identified to analyze its corresponding actions. These insights could be applied to improve the conservation policies and guide the sustainable management and economic valuation plans to implement the Moroccan Medicinal and aromatic plants strategy. [ABSTRACT FROM AUTHOR]

Context. The broad concepts and generalisations that guide conduct of applied ecology, including wildlife management, have been reviewed and synthesised recently into 22 prescriptive and three empirical principles. Aims. The aim of this study was to use these principles to evaluate three on-ground wildlife management programs and assess the utility of the principles themselves. Key results. Case studies of long-term management of national park biodiversity impacted by feral pigs (Sus scrofa), and of conservation and harvest of red kangaroos (Macropus rufus) and mallards (Anas platyrhnchos), were selected to provide a representative range of management objectives, spatial scales and land tenures, and to include both native and introduced species. Management documents and a considerable scientific literature were available for all three programs. The results highlight similarities and differences among management activities and demonstrate the 25 principles to differing degrees. Most of the prescriptive principles were demonstrated in both the management and the scientific literature in all three programs, but almost no use was made of the three empirical principles. We propose that use of the prescriptive principles constitutes evidence that these programs meet both societal and scientific expectations. However, the limited use of the empirical principles shows gaps in the three programs. Conclusions. The results suggest that evaluating other wildlife management programs against the principles of applied ecology is worthwhile and could highlight aspects of those programs that might otherwise be overlooked. Little use was made of the empirical principles, but the the Effort-outcomes principle in particular provides a framework for evaluating management programs. Implications. The effort-outcomes relationship should be a focus of future applied research, and both prescriptive and empirical principles should be integrated into wildlife management programs. [ABSTRACT FROM AUTHOR]

The European black truffle is a mycorrhizal fungus native to Spanish Mediterranean forests. In most Spanish regions it was originally commercially harvested in the second half of the 20th century. Experts agree that wild truffle yields suffered a sharp decline during the 1970s and 1980s. However, official statistics for Spanish harvest are scarce and seemingly conflicting, and little attention has been paid to the regime for the exploitation of truffle-producing forests and its implications on the sustainability of this resource. Trends in harvest from 1969 to 2013 and current harvesting practices were analyzed as a case study, taking into account that Spain is a major truffle producer worldwide, but at the same time truffles have only recently been exploited. The available statistical sources, which include an increasing proportion of cultivated truffles since the mid-1990s, were explored, with estimates from Truffle Harvesters Federation showing higher consistency. Statistical sources were then compared with proxies for wild harvest (rents from truffle leases in public forests) to corroborate time trends in wild harvesting. Results suggest that black truffle production is recovering in recent years thanks to plantations, whereas wild harvest is still declining. The implications of Spanish legal and institutional framework on sustainability of wild truffle use are reviewed. In the current scenario, the decline of wild harvest is likely to continue and eventually make commercial harvesting economically unattractive, thus aggravating sustainability issues. Strengthening of property rights, rationalization of harvesting pressure, forest planning and involvement of public stakeholders are proposed as corrective measures. [ABSTRACT FROM AUTHOR]

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

During the late 1970s I developed an idea that later became known as 'sheep replacement for rangelands'. It grew from the realisation, gained during hundreds of hours of low flying on kangaroo surveys, that overgrazing by sheep was turning, or had already turned Australia's 'sheep rangelands' into desert. Seeking an economically productive alternative, I imagined a scenario in which the value of kangaroo meat could be increased enough, by effective marketing, to encourage wool growers to see kangaroos as a resource rather than a pest, and to reduce sheep numbers and, thus, total grazing pressure. The implication was that kangaroo meat would be marketed for human consumption, relying on its low fat, high protein characteristics, making it a healthier alternative to traditional livestock. Eating wild meat is not a new idea; humans were hunter gatherers until the last 8-10 thousand years. But the idea of marketing kangaroo meat in the service of land conservation was an idea that was hard for many people to get their heads around, and a hoped for marketing drive never eventuated. Now, almost 30 years since the idea was first published, kangaroos are still regarded as pests, kangaroo meat is still undervalued, and rangeland degradation continues apace. Indeed, recent developments are leading to what will be even more damaging forces driving rangeland destruction. There has indeed been 'sheep replacement', but in many areas it has been by goats. The goat meat industry is booming and history tells us that the rangelands will suffer further as a result. Additionally, 'cluster' fencing, introduced in some areas for wild dog control, is being hailed as a good way to 'manage' kangaroos. The future of the rangelands remains bleak. [ABSTRACT FROM AUTHOR]

This paper evaluates the outcomes from an ambitious wildflower harvesting programme in South Africa's Western Cape, which has sought to achieve positive outcomes in terms of socio-economic development and biodiversity conservation. Indigenous wildflowers, harvested according to conservation principles, are processed into 'Cape Flora' bouquets and sold into international and domestic markets. The principal supply chain provides an example of ethical trade due to the explicit environmental and social standards that are required at local sites of production. The incorporation of such standards represents an attempt to engender economic and social upgrading within the value chain. In this sense, the programme is consistent with dominant policy discourses, which suggest that exploiting potentially profitable niches within international trade flows represents a 'high road' to economic growth and transformation. The paper focuses upon the job creation and social impacts of the programme in the context of efforts to overcome South Africa's deeply entrenched socio-economic disparities and high poverty levels. Despite impressive growth in production and exports during the global financial crisis, there have been mixed outcomes in terms of benefits to stakeholders at the upstream end of the supply chain. The paper concludes by considering the extent to which local initiatives operating under the framework of ethical trade possess the potential to facilitate effective social and economic upgrading. [ABSTRACT FROM AUTHOR]

The seabob shrimp Xiphopenaeus kroyeri ranks third in commercial importance among fisheries in southeastern Brazil. An important management question is whether the same offseason can be applied to different regions. The population dynamics of the seabob shrimp was compared in two regions of southeastern Brazil: Macaé, state of Rio de Janeiro and Ubatuba, state of São Paulo. All demographic categories of shrimp in the Macaé region were larger than those in the Ubatuba region. Lower temperatures and greater longevities in the Macaé region may account for this difference in size from Ubatuba. In Macaé, number of reproductive females and juveniles correlated with organic-matter content. In Ubatuba, only chlorophyll-a showed a correlation with reproductive females. The reproductive period and recruitment were correlated in both populations. The difference in environmental factors between these regions, resulting of the Cabo Frio upwelling, although they are located close together, directly influences the population dynamics of X. kroyeri. The Cabo Frio upwelling may be acting as a physical barrier, preventing gene flow and differentiating the seabob shrimp stocks in the two regions. These data suggest that different offseason periods for different regions could increase the sustainability of shrimp harvesting along the Brazilian coast. [ABSTRACT FROM AUTHOR]

The purple sea urchin P. lividus is a marine resource greatly valued for its highly nutritious roe. The objective of this work is to analyse the spatial distribution pattern and population structure of this species in the region of Cantabria (Bay of Biscay) in order to identify the most appropriate zones for sustainable harvesting and for the establishment of adequate management strategies. Two depth ranges were studied (<5 and 5–10 m) in five coastal areas. The available stock of commercial individuals (size >55 mm) was estimated based on the density of individuals and biometric parameters. Significant differences were found among areas but not among depth ranges. Three areas showed low densities with large individuals, whereas two areas showed high densities with small individuals. Despite the average smaller size of the individuals, these high-density areas accumulated 76% of the commercial stock, making these the most suitable zones for the sustainable harvesting of P. lividus in the region. The high variability of the observed density values resulted in elevated uncertainty in the estimation of stocks. However, the high sea urchin densities together with the high percentages of commercial individuals suggest that the resource is currently underexploited. Further studies should be carried out, and precautionary measures should be adopted before opening the fishery. The suitability of many of these measures is discussed in the present work, as a necessary step in the management of the P. lividus fishery in Cantabria. [ABSTRACT FROM PUBLISHER]

Underprivileged communities rely on beneficial plants for medicinal and cultural purposes as well as income generation. They are marginalised by land use planners, politicians and municipalities, resulting in biased integrated development and increased poverty. A case in point, is the Critically Endangered Woodbush Granite Grassland (WGG) in Limpopo Province, South Africa. The WGG has high plant biodiversity (661 species in 192 ha), which includes 18 Red Listed taxa and 36 taxa protected by existing legislation. Although 18% of the plant species have medicinal properties and the area is a source of plants used for medicine and hand brushes, this is the first ethnobotanical study to be undertaken here. Structured interview schedules were conducted with 54 people who were using plants from the area, and a list of the top 20 medicinal plants was compiled. Respondents raised concerns regarding the impact of fire management and 69% of traditional healers noted increasing difficulty in finding useful plants in the last decade. The majority of plant harvesters supported choices related to protecting the ecosystem. Propagated plants were considered to be an option by 60% of plant harvesters but serious risks to success were raised, suggesting thatin situbiodiversity preservation was key to securing traditional healthcare and cultural practice. The socio-ecological system that exists is described and requires recognition by state bodies responsible for conservation and social welfare. [ABSTRACT FROM AUTHOR]

This research established the time consumption, work time structure, and productivity for primary processing in felling areas of coniferous trees felled with a chainsaw. Delimbing and partial cross-cutting were taken into consideration. The research was conducted in a mixed spruce and fir tree stand situated in the Carpathian Mountains. The team of workers consisted of a chainsaw operator and assistant with over 10 years of experience. The results indicated a total time of 536.32 s·m−3 (1145.26 s·tree−1), work performance (including delays) of 6.716 m3·h−1 (3.14 tree·h−1), and work productivity (without delays) of 35.459 m3·h−1 (16.58 tree·h−1). The chainsaw productivity during tree cross-cutting was 82.29 cm2·s−1. Delimbing accounted for 96.18% of the real work time, while cross-cutting accounted for 3.82%. The time consumption for delimbing and cross-cutting, as well as the work productivity and performance in the primary processing of coniferous trees in the felling area, were influenced by the breast height diameter, stem length, and tree volume, while the chainsaw productivity was influenced by the diameter of the cross-cut sections. The relationships between the aforementioned dependent and independent variables were determined by simple and linear multiple regression equations.