Monitoring tropical forests under a functional perspective with satellite‐based vegetation optical depth

Monitoring ecosystem functions in forests is a priority in a climate change scenario, as climate‐induced events may initially alter the functions more than slow‐changing attributes, such as biomass. The ecosystem functional properties (EFPs) are quantities that characterize key ecosystem processes. They can be derived by point observations of gas and energy exchanges between the ecosystems and the atmosphere that are collected globally at FLUXNET flux tower sites and upscaled at ecosystem level. The properties here considered describe the ability of ecosystems to optimize the use of resources for carbon uptake. They represent functional forest information, are dependent on environmental drivers, linked to leaf traits and forest structure, and influenced by climate change effects. The ability of vegetation optical depth (VOD) to provide forest functional information is investigated using 2011–2014 satellite data collected by the Soil Moisture and Ocean Salinity mission and using the EFPs as reference dataset. Tropical forests in Africa and South America were analyzed, also according to ecological homogeneous units. VOD jointly with water deficit information explained 93% and 87% of the yearly variability in both flux upscaled maximum gross primary productivity and light use efficiency functional properties, in Africa and South America forests respectively. Maps of the retrieved properties evidenced changes in forest functional responses linked to anomalous climate‐induced events during the study period. The findings indicate that VOD can support the flux upscaling process in the tropical range, affected by high uncertainty, and the detection of forest anomalous functional responses. Preliminary temporal analysis of VOD and EFP signals showed fine‐grained variability in periodicity, in signal dephasing, and in the strength of the relationships. In selected drier forest types, these satellite data could also support the monitoring of functional dynamics.     

Redundancy in wildflower strip species helps support spatiotemporal variation in wild bee communities on diversified farms

Wildflower strips are a management practice increasingly used to provide floral resources to wild bees in agroecosystems. Yet, despite known spatiotemporal variation in wild bee communities, the degree to which different wildflower strip species consistently support wild bee communities is poorly understood. Additionally, whether such consistency is related to the functional roles wildflower species play (e.g., in supporting diverse, rare, or unique suites of bee species) has not been considered. Over three years and on four diversified farms, we evaluated spatiotemporal variation in wild bee communities and bee-flower interactions in wildflower strips to better understand the roles of flower strip species in supporting bees. We documented spatiotemporal variation in the abundance, richness, and composition of local wild bee communities. Certain wildflower species consistently supported the highest richness of wild bees across years. These wildflower species were regularly core members of the bee-flower interaction network, visited by both generalist and specialist bees. By contrast, wildflower species supporting the most unique suites of bees were variable in this role among farms. In order to select plant species for wildflower strips that consistently support a high diversity of wild bee communities within farm landscapes, it is useful to consider several different functional roles that plants may play. Whereas a handful of wildflower species may be visited by the majority of local wild bee species, achieving support for the remaining, and perhaps rarer, bee species will require planting additional flower species, which may appear redundant until the spatiotemporal variation in wild bee communities is more thoroughly considered. This functional approach to selecting wildflower species for bee conservation efforts is important for making practical recommendations to land managers and for guiding best management practices in different regions and with diverse management goals.     

Post‐fire development of faunal habitat depends on plant regeneration traits

The concept that vegetation structure (and faunal habitat) develops predictably with time since fire has been central to understanding the relationship between fire and fauna. However, because plants regenerate after fire in different ways (e.g. resprouting from above‐ground stems vs. underground lignotubers), use of simple categories based on time since fire might not adequately represent post‐fire habitat development in all ecosystems. We tested the hypothesis that the post‐fire development of faunal habitat structure differs between ecosystems, depending on fire regeneration traits of the dominant canopy trees. We measured 12 habitat components at sites in foothill forests (n = 38), heathy woodlands (n = 38) and mallee woodlands (n = 98) in Victoria, Australia, and used generalised additive models to predict changes in each variable with time since fire. A greater percentage of faunal habitat variables responded significantly to time since fire in mallee woodlands, where fires typically are stand‐replacing, than in foothill forests and heathy woodlands, where canopy tree stems generally persist through fire. In the ecosystem with the highest proportion of epicormic resprouters (foothill forests), only ground cover and understorey vegetation responded significantly to time since fire, compared with all but one variable in the ecosystem dominated by basal resprouters (mallee woodlands). These differences between ecosystems in the post‐fire development of key habitat components suggest there may also be fundamental differences in the role of fire in shaping the distribution of fauna. If so, this challenges the way in which many fire‐prone ecosystems currently are categorised and managed, especially the level of dependence on time since fire and other temporal surrogates such as age‐classes and successional states. Where time since fire is a poor surrogate for habitat structural development, additional complexity (e.g. fire severity, topography and prior land‐use history) could better capture processes that determine faunal occurrence in fire‐prone ecosystems.     

Alpine grassland plants grow earlier and faster but biomass remains unchanged over 35 years of climate change

Satellite data indicate significant advancement in alpine spring phenology over decades of climate warming, but corresponding field evidence is scarce. It is also unknown whether this advancement results from an earlier shift of phenological events, or enhancement of plant growth under unchanged phenological pattern. By analyzing a 35‐year dataset of seasonal biomass dynamics of a Tibetan alpine grassland, we show that climate change promoted both earlier phenology and faster growth, without changing annual biomass production. Biomass production increased in spring due to a warming‐induced earlier onset of plant growth, but decreased in autumn due mainly to increased water stress. Plants grew faster but the fast‐growing period shortened during the mid‐growing season. These findings provide the first in situ evidence of long‐term changes in growth patterns in alpine grassland plant communities, and suggest that earlier phenology and faster growth will jointly contribute to plant growth in a warming climate.     

Ecosystem services provided by armadillos

Awareness of the natural ecological processes provided by organisms that benefit human well‐being has significantly progressed towards the goal of making conservation a mainstream value. Identifying different services and the species that provide them is a vital first step for the management and maintenance of these so‐called ecosystem services. Herein, we specifically address the armadillos, which play key functional roles in terrestrial ecosystems, including as ecosystem engineers, predators, and vectors of invertebrates and nutrients, although these roles have often been overlooked. Armadillos can control pests, disperse seeds, and be effective sentinels of potential disease outbreaks or bioindicators of environmental contaminants. They also supply important material (meat, medicines) and non‐material (learning, inspiration) contributions all over the Americas. We identify key gaps in the understanding of ecosystem services provided by armadillos and areas for future research required to clarify their functional role in terrestrial ecosystems and the services they supply. Such information will produce powerful arguments for armadillo conservation.     

Medical physics graduate education in Mexico and its relation to the advances in radiation oncology

AimTo evaluate the state of graduate education in medical physics and progress in radiation oncology (RO) equipment in Mexico since 2000, when conferring degrees from two master’s-degree programs in Medical Physics began.BackgroundMedical physics is a Health Profession and there are international recommendations for education, training, and certification. Both programs follow these education guidelines. The most common clinical occupation of graduates is in RO services. Techniques in Mexican RO include traditional and high-precision procedures.MethodsAcademic and occupational information about the programs and their graduates were obtained from official websites. Graduates were invited to respond to a survey that requested information about their present job. We obtained data on RO equipment and human resources from public databases and estimated staffing requirements of medical physicists (MPs).ResultsMedical physics programs have graduated a total of 225 MPs. Half of them work in a clinical environment and, of these, about 90 work in RO services. MPs with M.Sc. degrees constitute 36% of the current MP workforce in RO, estimated to be 250 individuals. Survey responses pointed out the main merits and limitations of the programs. The number of MPs in RO has increased fivefold and the number of linacs sixfold in 15 years. The present number of MPs is insufficient, according to published guidelines.ConclusionAll MPs in RO services with advanced modalities must be trained following international recommendations for graduate education and post-graduation clinical training. Education and health institutions must find incentives to create more graduate programs and clinical residencies.