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29
result(s) for
"biophysical constraint"
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Toward a metabolic theory of life history
2019
The life histories of animals reflect the allocation of metabolic energy to traits that determine fitness and the pace of living. Here, we extend metabolic theories to address how demography and mass–energy balance constrain allocation of biomass to survival, growth, and reproduction over a life cycle of one generation. We first present data for diverse kinds of animals showing empirical patterns of variation in life-history traits. These patterns are predicted by theory that highlights the effects of 2 fundamental biophysical constraints: demography on number and mortality of offspring; and mass–energy balance on allocation of energy to growth and reproduction. These constraints impose 2 fundamental trade-offs on allocation of assimilated biomass energy to production: between number and size of offspring, and between parental investment and offspring growth. Evolution has generated enormous diversity of body sizes, morphologies, physiologies, ecologies, and life histories across the millions of animal, plant, and microbe species, yet simple rules specified by general equations highlight the underlying unity of life.
Journal Article
Trade-offs in ecosystem services and varying stakeholder preferences
by
Polasky, Stephen
,
King, Elizabeth
,
Balvanera, Patricia
in
Biodiversity conservation
,
biophysical constraint
,
conflict
2015
In efforts to increase human well-being while maintaining the natural systems and processes upon which we depend, navigating the trade-offs that can arise between different ecosystem services is a profound challenge. We evaluated a recently developed simple analytic framework for assessing ecosystem service trade-offs, which characterizes such trade-offs in terms of their underlying biophysical constraints as well as divergences in stakeholders’ values for the services in question. Through a workshop and subsequent discussions, we identified four different types of challenging situations under which the framework allows important insights to clarify the nature of stakeholder conflicts, obstacles to promoting more sustainable outcomes, and potential enabling factors to promote efficiency and sustainability of ecosystem service yields. We illustrated the framework’s analytical steps by applying them to case studies representing three of the challenging situations. We explored the fourth challenging situation conceptually, using published literature for examples. We examined the potential utility and feasibility of using the framework as a participatory tool in resource management and conflict resolution. We concluded that the framework can be instrumental for promoting pluralism and insightful analysis of tradeoffs. The insights offered here may be viewed as hypotheses to be tested and refined as additional unforeseen challenges and benefits are revealed as the framework is put into practice.
Journal Article
Towards identifying industrial crop types and associated agronomies to improve biomass production from marginal lands in Europe
by
Fernando, Ana L.
,
Lamy, Isabelle
,
Alexopoulou, Efthymia
in
Acidity
,
Agricultural land
,
Agricultural management
2022
Growing industrial crops on marginal lands has been proposed as a strategy to minimize competition for arable land and food production. In the present study, eight experimental sites in three different climatic zones in Europe (Mediterranean, Atlantic and Continental), seven advanced industrial crop species [giant reed (two clones), miscanthus (M. × giganteus and two new seed‐based hybrids), saccharum (one clones), switchgrass (one variety), tall wheatgrass (one variety), industrial hemp (three varieties) and willow (eleven clones)], and six marginality factors alone or in combination (dryness, unfavorable texture, stoniness, shallow soil, topsoil acidity, heavy metal and metalloid contamination) were investigated. At each site, biophysical constraints and low‐input management practices were combined with prevailing climatic conditions. The relative yield of a site‐specific low‐input system compared with the site‐specific control was from small to large (i.e. from −99% in industrial hemp in the Mediterranean to +210% in willow in the Continental zone), due to the genotype‐by‐management interaction along with climatic variation between growing seasons. Genotype selection and improved knowledge on crop response to changing environmental, site‐specific biophysical constraint and input application has been detected as key to profitably grow industrial crops on marginal areas. This study may act to provide hints on how to scale up investigated cropping systems, through low‐input practices, under similar environmental and soil conditions tested at each site. However, further attention to detail on the agronomy of early plant development and management in larger multi‐year and multi‐location field studies with commercially scalable agronomies are needed to validate yield performances, and thereby to inform on the best industrial crop options. Growing industrial crops on marginal lands has been proposed as a strategy to minimize competition for arable land and food production. This study can bring an advancement to knowledge on the suitability of certain industrial crops to marginal and contaminated soils to mitigate indirect land‐use change (i‐LUC) in accordance with the RED II and to meet the European Green Deal towards an EU climate neutral in 2050. It ultimately can assist to make general recommendations of the most appropriate crop and management options at the different regions, climates, soils and marginal land types.
Journal Article
Unravelling the critical insights on the physiological and biophysical constraints for the impact of different intensity of shade in pigeonpea Cajanas cajan (L.)
2024
Critical influence of different level of shade on the underlying physiological and biophysical limitations of an important pulse crop pigeonpea [(Cajanas cajan (L.)] has been investigated. The crop was grown under three level of shade intensity 33% (S1), 50% (S2), 75% (S3) based on the incident sunlight intensity as obtained through providing different category of shade-net in shade-net house facilities and the open field (open) without shade. Major impact has been observed on photosynthetic CO2 assimilation (Amax), leaf water use efficiency (WUEi), photosynthetic radiation use efficiency (PRUE) and biophysical constraints relating to photosynthetic light energy utilization. Efficiency of the crop for light energy utilization has been assessed through chlorophyll fluorescence traits for Photosystem II (PSII) functioning, leaf level physio-biophysical indicators and the leaf spectral traits. The functional traits were responsible for the critical impact of shade causing limitation to get maximum potential performance of the crop. Amax was noted 22.58 µ mol CO2 m−2 s−1 in open sun light grown plants (Open) whereas, 19.91, 13.03 and 7.20 at S1, S2 and S3 level of shade respectively. In comparison to open, transpiration rate (E) declined by only 4.6% at S1 level of shade whereas it substantially decreased by 44.4% and 68.3% at S2 and S3 level of shade respectively. Differential reduction in the physiological and leaf biophysical responses depending on the intensity of shade suggested that the physiological functioning of the crop has been progressively diminished over and above the S1. Electron transport rate across PSII (ETR) marginally reduced at S1 by 10.65% while it progressively decreased at S2 (31.07%) and S3 (55.17%) level of shade in comparison to open. The findings have clearly revealed that the limitation of electron supplies through PSII and their inefficient utilization for driving the photosynthetic carbon acquisition were the major limiting factors for achieving the potential performance of the crop under shade. The results would be useful for searching for better crop to cope with the limitation of shade through achieving shade-tolerance or shade-resilience in crops for agroforestry importance. The present work offers a perspective as to how different intensity of shades impair the various aspects involving the important pulse crop i.e. pigeonpea which will further improve our understanding of the functional importance of the physiological and biophysical processes involved to alleviate the major constraints posed by shade. Further, the present study has revealed that about 33% shade (S1) based on the incident sun light, can be a critical limit for the crop as the deep (S2) and extreme (S3) shade has highly detrimental effects on the physiology of the crop which remarkably affects the grain yield production.
Journal Article
Identification of Arable Marginal Lands under Rainfed Conditions for Bioenergy Purposes in Spain
by
Ciria, Carlos S.
,
Carrasco, Juan
,
Sanz, Marina
in
Agriculture
,
Alternative energy sources
,
Barley
2019
The cultivation of bioenergy crops could be considered as sustainable; however, its use in fertile lands could conflict with food production. The general purpose of this study is to identify areas where traditional food crops are not economically sustainable, but where they could be substituted by energy crops without changing the land use in Spain. We studied the profit margin of the main crops of the country, which are wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), the spatial location of the growing areas, and the biophysical constraints. Spain has an extended area of 9.93 million hectares, with biophysical and/or economic constraints in rainfed arable areas. Grain yields ≤1.5 Mg ha−1 are not profitable; low organic matter content is the principal biophysical constraint. The average results showed a potential of 83.33 GJ ha−1 using triticale (x Triticosecale) and 174.85 GJ ha−1 using cardoon (Cynara cardunculus L.) in arable marginal lands. The production of biomass in this area would serve to cover between 3%–5% of primary energy needs in Spain for triticale or cardoon. In this respect, establishing energy crops in marginal lands could be an instrument to enhance rural development, boost the bio-economy, and reach environmental targets.
Journal Article
Ecosystem service trade-offs across global contexts and scales
by
Polasky, Stephen
,
Balvanera, Patricia
,
King, Elizabeth
in
Agroecology
,
Biodiversity
,
Biodiversity conservation
2015
Meeting human needs while sustaining the planet’s life support systems is the fundamental challenge of our time. What role sustenance of biodiversity and contrasting ecosystem services should play in achieving a sustainable future varies along philosophical, cultural, institutional, societal, and governmental divisions. Contrasting biophysical constraints and perspectives on human well-being arise both within and across countries that span the tropics and temperate zone. Direct sustenance of livelihoods from ecosystem services in East Africa contrasts with the complex and diverse relationships with the land in Mexico and the highly monetary-based economy of the United States. Lack of understanding of the contrasting contexts in which decision-making about trade-offs occurs creates impediments to collective global efforts to sustain the Earth’s life support systems. While theoretical notions of the goals of sustainability science seek a unified path forward, realities on the ground present challenges. This Special Feature seeks to provide both an analytical framework and a series of case studies to illuminate impediments posed to sustainability by contrasting biophysical constraints and human perspectives on what should be sustained. The contributors aim to clarify the trade-offs posed to human welfare in sustaining biodiversity and ecosystem services and the challenges in managing for a sustainable future in which human well-being is not compromised as compared to today. Our goal is to provide novel insights on how sustainability can be achieved internationally through exploration of constraints, trade-offs, and human values examined at multiple scales, and across geographic regions from a range of cultural perspectives.
Journal Article
Biophysical and Social Constraints of Restoring Ecosystem Services in the Border Regions of Tibet, China
by
Hua, Ting
,
Zha, Xinjie
,
Jia, Lizhi
in
Agricultural production
,
Biodiversity
,
biophysical constraints
2025
Ecosystem restoration represents a promising solution for enhancing ecosystem services and environmental sustainability. However, border regions—characterized by ecological fragility and geopolitical complexity—remain underrepresented in ecosystem service and restoration research. To fill this gap, we coupled spatially explicit models (e.g., InVEST and RUSLE) with scenario analysis to quantify the ecosystem service potential that could be achieved in China’s Tibetan borderlands under two interacting agendas: ecological restoration and border-strengthening policies. Restoration feasibility was evaluated through combining local biophysical constraints, economic viability (via restoration-induced carbon gains vs. opportunity costs), operational practicality, and simulated infrastructure expansion. The results showed that per-unit-area ecosystem services in border counties (particularly Medog, Cona, and Zayu) exceed that of interior Tibet by a factor of two to four. Combining these various constraints, approximately 4–17% of the border zone remains cost-effective for grassland or forest restoration. Under low carbon pricing (US $10 t−1 CO2), the carbon revenue generated through restoration is insufficient to offset the opportunity cost of agricultural production, constituting a major constraint. Habitat quality, soil conservation, and carbon sequestration increase modestly when induced by restoration, but a pronounced carbon–water trade-off emerges. Planned infrastructure reduces restoration benefits only slightly, whereas raising the carbon price to about US$ 50 t−1 CO2 substantially expands such benefits. These findings highlight both the opportunities and limits of ecosystem restoration in border regions and point to carbon pricing as the key policy lever for unlocking cost-effective restoration.
Journal Article
Electrical neuroimaging based on biophysical constraints
by
Michel, Christoph M.
,
Martuzzi, Roberto
,
Gonzalez Andino, Sara L.
in
Biophysical constraints
,
Biophysics - methods
,
Brain Mapping - methods
2004
This paper proposes and implements biophysical constraints to select a unique solution to the bioelectromagnetic inverse problem. It first shows that the brain's electric fields and potentials are predominantly due to ohmic currents. This serves to reformulate the inverse problem in terms of a restricted source model permitting noninvasive estimations of Local Field Potentials (LFPs) in depth from scalp-recorded data. Uniqueness in the solution is achieved by a physically derived regularization strategy that imposes a spatial structure on the solution based upon the physical laws that describe electromagnetic fields in biological media. The regularization strategy and the source model emulate the properties of brain activity's actual generators. This added information is independent of both the recorded data and head model and suffices for obtaining a unique solution compatible with and aimed at analyzing experimental data. The inverse solution's features are evaluated with event-related potentials (ERPs) from a healthy subject performing a visuo-motor task. Two aspects are addressed: the concordance between available neurophysiological evidence and inverse solution results, and the functional localization provided by fMRI data from the same subject under identical experimental conditions. The localization results are spatially and temporally concordant with experimental evidence, and the areas detected as functionally activated in both imaging modalities are similar, providing indices of localization accuracy. We conclude that biophysically driven inverse solutions offer a novel and reliable possibility for studying brain function with the temporal resolution required to advance our understanding of the brain's functional networks.
Journal Article
Yield Performance of Woody Crops on Marginal Agricultural Land in Latvia, Spain and Ukraine
by
Daugaviete, Mudrite
,
Sanz, Marina
,
Ciria, Pilar
in
abandoned agricultural land
,
Abandoned land
,
Agricultural land
2022
Agricultural land abandonment due to biophysical and socioeconomic constraints is increasing across Europe. Meanwhile there is also an increase in bioenergy demand. This study assessed woody crop performance on several relevant types of marginal agricultural land in Europe, based on field experiments in Latvia, Spain and Ukraine. In Latvia, hybrid aspen was more productive than birch and alder species, and after eight years produced 4.8 Mg ha−1 y−1 on stony soil with sandy loam texture, when best clone and treatment combination was selected. In Spain, Siberian elm produced up to 7.1 Mg ha−1 y−1 on stony, sandy soil with low organic carbon content after three triennial rotations. In Ukraine, willow plantations produced a maximum of 10.8 Mg ha−1 y−1 on a soil with low soil organic carbon after second triennial rotation. The productivity was higher when management practices were optimized specifically to address the limiting factors of a site. Longer rotations and lower biomass yields compared to high-value land can be expected when woody crops are grown on similar marginal agricultural land shown in this study. Future studies should start here and investigate to what extent woody crops can contribute to rural development under these conditions.
Journal Article