Managing the herbage utilisation and intake by cattle grazing rangelands

2015 ◽  
Vol 55 (3) ◽  
pp. 397 ◽  
Author(s):  
J. W. Oltjen ◽  
S. A. Gunter
Keyword(s):  
Dynamic Models ◽  
Net Primary Production ◽  
Cattle Grazing ◽  
Economic Benefits ◽  
Temporal Scales ◽  
Ecological Services ◽  
Spatial And Temporal Scales ◽  
Weather Patterns ◽  
Herbage Intake

Rangelands throughout the world provide clean water, fix solar energy in plants, sequester carbon, and offer recreational opportunities, with other ecosystem goods and services, including food from wild and domestic herbivores. Grazing rangelands with cattle requires constant management to balance the economic sustainability of the farm with other ecological services that rangelands provide. The challenges in management arise from the diversity of the rangeland forage resources at extremely large spatial and temporal scales. To be able to predict the performance of cattle grazing in extensive rangeland environments, estimating herbage intake is paramount because it quantifies energy intake and performance. Nutrient demand is the major driver of herbage intake, and characteristics of the sward and terrain of the landscape dictate how this demand is met. System models that integrate changes in weather patterns and herbage over long periods of time will allow farmers and scientist to monitor changes in herbage mass and utilisation. Dynamic models that include herbage growth components sensitive to weather patterns and animal demands are needed to predict how long-term changes in beef herd management will affect performance and range condition. Vegetation indexes captured across biomes with satellites can accurately quantify the dynamics of aboveground net primary production and changes in nutritional value with confidence. The computer software, PCRANCH, is a program for simulating cow–calf herd dynamics over long periods of time. The models within the PCRANCH software can simulate herbage growth and animal utilisation at large spatial and temporal scales needed for rangeland management and allow ranchers to evaluate the impacts of management on other ecological services. Knowing the long-term impact of management changes on swards enable ranchers to anticipate the ecological and economic benefits of improvements or demonstrate a protection of current ecological services.

Long term trend of increasing iron stress in Southern Ocean phytoplankton

2021 ◽  
Author(s):  
Sandy Thomalla ◽  
Thomas Ryan-Keogh ◽  
Alessandro Tagliabue ◽  
Pedro Monteiro
Keyword(s):  
Southern Ocean ◽  
Primary Production ◽  
Net Primary Production ◽  
Earth System ◽  
Iron Stress ◽  
Temporal Scales ◽  
Spatial And Temporal Scales ◽  
Earth System Models

<p>Net primary production is a major contributor to carbon export in the Southern Ocean and supports rich marine ecosystems [Henley et al., 2020], driven in part by high macronutrient availability and summertime light levels, but ultimately constrained by seasonal changes in light and scarce supply of the essential micronutrient iron [Martin et al., 1990; Boyd, 2002; Tagliabue et al., 2016]. Although changing iron stress is a component of climate-driven trends in model projections of net primary production [Bopp et al., 2013; Laufkotter et al., 2015; Kwiatkowski et al., 2020], our confidence in the accuracy of their predictions is undermined by a lack of <em>in situ</em> constraints at appropriate spatial and temporal scales [Tagliabue et al., 2016; Tagliabue et al., 2020]. Earth System Models tend to predict increased Southern Ocean net primary production by the end of the 21st century, but are characterized by significant inter-model disagreement [Bopp et al., 2013; Kwiatkowski et al., 2020 Biogeosciences].  We show a significant multi-decadal increase in <em>in situ</em> iron stress from 1996 to 2020 that is positively correlated to the Southern Annular Mode and reflected by diminishing <em>in situ</em> net primary production over the last five years. It is not possible to directly infer Fe stress from observed concentrations, which necessitate experimental approaches (<em>in situ</em> open ocean fertilization / bottle nutrient addition experiments or proteomics). These experimental methods cannot be easily applied at appropriate spatial and temporal scales across the Southern Ocean that are required to assess trends in ecosystem status linked to climate drivers. Our novel proxy for <em>in situ</em> iron stress is based on the degree of non-photochemical quenching in relation to available light as a measurable photophysiological response to iron availability [Alderkamp et al., 2019; Schuback & Tortell, 2019; Schallenberg et al., 2020; Ryan-Keogh & Thomalla, 2020]. The proxy was able to reproduce expected variations in iron stress that occur seasonally [Boyd, 2002] and from natural and artificial fertilization [Boyd et al., 2000; Coale et al., 2004; Blain et al., 2008]. A particular strength of this iron stress proxy is that it can be retrospectively applied to data from ships and autonomous platforms with coincident measurements of fluorescence, photosynthetically active radiation and backscatter or beam attenuation to deliver a long-term time series. An iron stress trend of this magnitude in the Southern Ocean, where the primary constraint on net primary production is known to be iron limitation, is likely to have significant implications for the effectiveness of the biological carbon pump globally and may impact the trajectory of climate. The progressive <em>in situ</em> trend of increasing iron stress is however much stronger than net primary production trends from a suite of remote sensing and earth system models, indicating hitherto potential underestimation of ongoing Southern Ocean change.</p>

scholarly journals The Importance of Multi-Scale Temporal and Spatial Management for Cemetery Trees in Malmö, Sweden

Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 78
Author(s):  
Jessica M. Quinton ◽  
Johan Östberg ◽  
Peter N. Duinker
Keyword(s):  
Species Diversity ◽  
Urban Forests ◽  
Effective Management ◽  
Temporal Scales ◽  
Spatial And Temporal Scales ◽  
Tree Management ◽  
Multi Scale ◽  
Age Class ◽  
Management Plans

Research Highlights: A large body of research highlighted the important contributions that urban forests make to cities and their inhabitants. However, our urban forests face threats from issues such as rapid urbanization, climate change, and the spread of pests and diseases. As such, proactive and effective management is necessary to ensure their long-term sustainability. Given the multiple spatial and temporal scales on which threats can arise, effective management needs to account for these scales and adjust accordingly. The degree to which this currently happens is unclear. Background and Objectives: The aim of this study was to determine the role of multi-scale management in urban forestry, using cemeteries in Malmö, Sweden as a case study. Cemeteries can provide extensive tree canopy but are not readily considered in urban forest management. We sought to determine (1) the threats to the current cemetery tree populations, (2) the extent of multi-scale cemetery tree management, (3) whether tree management plans promote multi-scale management, and (4) how cemetery tree management can be improved. Materials and Methods: Malmö cemetery tree inventories were analyzed with respect to size class and species diversity. Existing cemetery tree management plans were examined to determine the spatial and temporal scales of their recommendations. Interviews were conducted with cemetery managers to determine management priorities and actions. Results: We found that cemetery tree populations in Malmö suffer from a lack of age class and species diversity. Management tends to occur on short time scales and efforts focus mainly on addressing individual trees, although some consideration is given to large-scale species diversification. The management plans previously created for these cemetery trees make recommendations for age class and species diversification but are yet to be used extensively by cemetery managers. Conclusions: The long-term stability of Malmö’s cemetery tree populations is threatened by a lack of species and age diversity. Current management efforts emphasize addressing small-scale issues. Although there is a desire to improve species diversity, this can cause conflict with existing cultural values.

scholarly journals The Homogocene: a research prospectus for the study of biotic homogenisation

NeoBiota ◽  
2018 ◽  
Vol 37 ◽  
pp. 23-36 ◽  
Author(s):  
Julian D. Olden ◽  
Lise Comte ◽  
Xingli Giam
Keyword(s):  
Global Change ◽  
Biological Diversity ◽  
Significant Progress ◽  
Temporal Scales ◽  
Spatial And Temporal Scales ◽  
Conservation Implications ◽  
The World ◽  
Biotic Homogenisation ◽  
Long Term Preservation

In an era of global change, the process of biotic homogenisation by which regional biotas become more similar through time has attracted considerable attention from ecologists. Here, a retrospective look at the literature is taken and the question asked how comprehensive is the understanding of this global phenomenon? The goal is to identify potential areas for additional and future enquiries to advance this research frontier and best ensure the long-term preservation of biological diversity across the world. Six propositions are presented here to; (1) broaden our geographic and taxonomic understanding, (2) diversify the spatial and temporal scales of inquiry, (3) reconcile past and embrace new approaches to quantification, (4) improve our knowledge of the underlying drivers, (5) reveal the conservation implications and (6) forecast future homogenisation. It is argued that significant progress in the understanding of the causes, consequences and conservation implication of biotic homogenisation will come by integrating concepts and approaches from ecology, evolution and conservation across a hierarchy of spatial and temporal scales.

Climate and Climatological Variations in the Jornada Basin

2006 ◽  
Author(s):  
John Wainright
Keyword(s):  
Spatial Variability ◽  
Time Scales ◽  
Large Scale ◽  
Temporal Scales ◽  
Extreme Rainfall Events ◽  
Spatial And Temporal Scales ◽  
Circulation Patterns ◽  
Jornada Basin ◽  
Instrumental Records

The purpose of this chapter is to review the climatic data for the Jornada Basin over the period for which instrumental records exist. Over this time period, up to 83 years in the case of the Jornada Experimental Range (JER), we can deduce both the long-term mean characteristics and variability on a range of different spatial and temporal scales. Short-term variability is seen in individual rainstorms. Longer-term patterns are controlled spatially by factors such as large-scale circulation patterns and basin and regional orography and temporally by the large-scale fluctuations in atmospheric and oceanic circulation patterns. Variability can have significant impacts on the biogeography of a region (Neilson 1986) or its geomorphic processes (Cooke and Reeves 1976), which may set in motion a series of feedbacks, most important those referring to desertification (Schlesinger et al. 1990; Conley et al. 1992). Understanding the frequency and magnitude of such variability is therefore fundamental in explaining the observed landscape changes in areas such as the Jornada Basin. The patterns observed for different climatic variables within the available instrumental records for the Jornada Basin are defined in a hierarchical series of temporal scales, starting with the patterns that emerge from long-term average conditions and moving to seasonal and monthly, daily, and subdaily time scales. Two further analyses are made because of their potential importance to the hydrological and ecological characteristics of the basin, namely, the occurrence of extreme rainfall events and of longer-term changes. The effects of El Niño events in controlling the rainfall over decadal time scales will be addressed in particular. Spatial variability is an additional important concern, especially when characterizing dryland areas such as the Jornada Basin, where spatial variability tends to be high. The overall climate of the basin can be defined according to the Köppen classification as being cool and arid, belonging to the midlatitude desert zone (BWk). However, interannual variability is important, and occasionally, the annual conditions are more characteristic of the semiarid steppe (BSk) zone. The higher rainfall rates in the higher altitudes of the basin are also more characteristic of semiarid conditions.

Trade-offs of Participation in the Long-Term Ecological Research Program: Immediate and Long-Term Consequences

2016 ◽  
Author(s):  
Lawrence R. Walker ◽  
Michael R. Willig
Keyword(s):  
Ecosystem Dynamics ◽  
Data Sets ◽  
Ecological Research ◽  
Temporal Scales ◽  
Spatial And Temporal Scales ◽  
Trade Offs ◽  
Long Term Ecological Research ◽  
Collaboration And Communication ◽  
Program Change

For those who may have skipped to this chapter and not read the 3 introductory chapters, the 36 essays, or the 4 evaluative chapters of this book, the answer to the burning question “Does participation in the Long-Term Ecological Research (LTER) program change scientists?” is an unequivocal “Yes!” As Boyer and Brown (Chapter 41) point out, however, those changes are mostly in the realms of knowledge acquisition and behavior adoptions in the practice of science. Participation in the program did not appear to have a substantial effect on the development of attitudes. Could such changes have occurred outside of the LTER program? Schlesinger (Chapter 40) thinks so. He suggests that the LTER program provides “some structure and modest standardization to a set of common measurements” but that it has not substantially broadened or deepened the ecological sciences. Yet the effect of the LTER program on science, while a fascinating and often-addressed question, is not the focus of this book (see Willig and Walker, Chapter 1). Of course, to address how scientists change also involves understanding how they approach and conduct science. In addition, personal change occurs in a broad societal context. For example, the LTER program has coincided with and helped promote a transition in ecology from research done by one or a few investigators on a particular organism or process in a particular habitat to investigations involving multidisciplinary teams working together to test models about how ecosystem dynamics unfold across large spatial and temporal scales. However, going to “big programs” and “big data sets” does not mean losing a sense of place or being divorced from the natural history of particular organisms. Even as spatial and temporal scales increase, ecological research is ideally still “place aware” (Bestelmeyer, Chapter 19). Using the essays of this book as a rich source of information to address fundamental questions about the nature of scientists, we provide some final thoughts on how the LTER program has affected its participants, particularly on how they view time and space, collaboration, and communication. We end with reflections on the future of ecology and society, based on the views expressed in this book and on our own participation in the LTER program.

Recovery of net primary production in subalpine meadows of Mount St. Helens following the 1980 eruption

1988 ◽  
Vol 66 (5) ◽  
pp. 989-997 ◽  
Author(s):  
William A. Pfitsch ◽  
L. C. Bliss
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
Summer Precipitation ◽  
Individual Species ◽  
Community Members ◽  
Nutrient Pools ◽  
Subalpine Meadows ◽  
Weather Patterns ◽  
Mount St Helens

The deposition of 5–10 cm of tephra from the 1980 eruption of Mount St. Helens had no more effect than subsequent yearly weather fluctuations on the net primary production of subalpine meadows. The net primary production of areas subject to cold mudflows slowly increased as surviving plants resprouted through the eroded surface and has remained below that of tephra deposition areas. The net primary production of tephra deposition areas fluctuated dramatically (coefficient of variation = 40%) in the seven summers following the eruption. An inverse relationship between net primary production and nutrient concentration of individual species contributed to stability in aboveground nutrient pools from year to year. The dominant community members responded similarly to differences among years in summer precipitation, with little evidence of compensatory growth that would help stabilize community production. Tephra greatly inhibited seedling establishment. Species density (number of species per square metre) and diversity (H′) declined in a community having species that rely on sexual reproduction for persistence and also in experimental tephra addition plots in a more species-rich community. These results indicate that although the short-term effect of tephra deposition on net primary production was minor, the long-term consequence will be of community simplification, which will contribute to fluctuation in net primary production in response to yearly weather patterns.

Modeling the Unique Attributes of Arid Ecosystems: Lessons from the Jornada Basin

2006 ◽  
Author(s):  
James F. Reynolds ◽  
Paul R. Kemp
Keyword(s):  
Net Primary Production ◽  
Arid Land ◽  
Arid Ecosystems ◽  
Temporal Scales ◽  
Ecosystem Responses ◽  
Spatial And Temporal Scales ◽  
External Forcings ◽  
Extreme Variability ◽  
Ecosystem Level ◽  
Jornada Basin

The Jornada Basin is typical of arid ecosystems of the Southwestern United States and many other regions of the globe: It is water-limited with low annual net primary production (ANPP) and low-standing crop (Szarek 1979; Ludwig 1987). Yet paradoxically, arid ecosystems are structurally and functionally quite complex, exhibiting a remarkable range of species compositions and system behaviors. This can be attributed in part to the presence of complex topography and landscape physiography (Mabbutt 1997; see also chapter 2) which, when combined with extreme variability in precipitation (Cavazos et al. 2002; Weltzin et al. 2003; see also chapter 3), produces striking spatial and temporal heterogeneity in the availability of essential limiting resources, such as water and mineral nutrients (MacMahon and Wagner 1985; see also chapters 5 and 6). In view of these complexities, one of the long-term objectives of the research in the Jornada Basin is to develop a synthetic understanding of the mechanisms and processes governing the complex patterns of arid land structure and functioning. It is clear that understanding and predicting potential cause–effect relationships will require considerable insights at multiple spatial and temporal scales (chapter 18). Models are expected to play an important role in this synthesis because most experiments and observations tend to take place at small spatial (e.g., 1–100 m2) and brief temporal scales (e.g., days, months, one to five years) (Levin 1992), whereas many ecosystem responses are the result of interacting factors and feedbacks operating over larger spatial and longer time periods (O’Neill et al. 1989; Levin 1992). In this chapter, we present a summary of some of the mechanistic models we developed as part of the Jornada Basin research program. Although our initial goal was largely focused on the relationship between precipitation and ecosystem functioning in the Jornada Basin, our work is sufficiently general that it should be applicable to other arid land regions of the world. Simulation modeling has a key role to play because it is difficult to experimentally examine even a partial spectrum of ecosystem-level responses that could result from abrupt perturbations, such as overgrazing and especially longer term external forcings, such as shifts in precipitation.

scholarly journals Restoration actions in marine ecosystems: a global analysis

2018 ◽  
Author(s):  
Simonetta Fraschetti ◽  
Giuseppe Guarnieri ◽  
Loredana Papa ◽  
Chris McOwen ◽  
Nadia Papadopoulou ◽  
...  
Keyword(s):  
Best Practices ◽  
Global Analysis ◽  
Global Scale ◽  
Temporal Scales ◽  
Project Duration ◽  
Spatial And Temporal Scales ◽  
Success Stories ◽  
Future Challenges ◽  
Ecosystem Level

A review of 573 studies on active restoration actions in the marine environment, published in the last 25 years, was carried out at global scale. We assessed how, where, at which spatial and temporal scales and under which socio-ecological settings restoration studies have been carried out, from very shallow to deep sea habitats. Results show that restoration efforts across habitats are increasing, especially in seagrasses and coral reefs, but never approached at ecosystem level. Targets, methods, response variables and standards are still very heterogeneous. Of the factors considered in the review, habitat, human impact intensity, realm and methods of restoration were found to be good determinant of restoration success. Short project duration (one-two years), small restoration areas (< 1 ha), lack of controls and knowledge of baselines are still a limit for deriving generalities. Finally, restorations rarely consider future challenges linked to global change this impairing long-term success stories. Restoration science needs more robust approaches leading to the development of best practices (e.g. protocols, monitoring of the effects, reasons for failure) to be applied at spatial and temporal scales so as to answer to present and future disturbance regimes.

Sign in / Sign up

Export Citation Format

Share Document