Ecological Resource Availability Research Articles

Native shrub densities predict burrow co-occurrence patterns in Central California Drylands

Ecological resource availability is crucial for the persistence and survival of local desert animal communities. Dryland resources such as shrubs and burrows positively benefit animal species by mitigating harsh abiotic factors and providing habitat. Understanding the role of native shrubs, many of which serve as foundation species within desert regions, as well as the function of underground burrows as resources, provides insights into habitat utilization. In this study, we seek to better understand the co-occurrence of these two resources as a first step in quantifying key patterns locally and regionally in drylands. We tested whether the presence of burrows increased with the density of foundational shrubs near the burrows at two scales—within a 5 m radius of every burrow recorded and at the site level—defined as discrete ecological areas. We performed fieldwork across 31 sites within the arid and semiarid regions of Central California. We used a combination of burrow field surveys and satellite imagery to document both vertebrate animal burrow frequencies and shrub densities. Additionally, the accuracy of the shrub data was verified through ground truthing. Both fine-scale and site-level shrub densities positively predicted the relative likelihood of burrows and the frequency of burrows, respectively. The existence of two highly utilized dryland resources and the relationship between them signal that areas abundant in both resources will likely better support resident animal species. This finding underscores the significance of incorporating both shrub density and burrow frequency in studies of habitat interconnectivity and quality. The co-occurrence patterns of these resources will support novel habitat management and conservation strategies designed around both conservation and restoration efforts.

Ecological resource availability: a method to estimate resource budgets for a sustainable economy

Non-technical summary Resources are the basis of our economy and their provision causes major shares of the global environmental burdens, many of which are beyond safe limits today. In order to be sustainable, our economy needs to be able to operate within those boundaries. As resources are the physical ‘currency’ of our economy, we present a method that allows translating Earth system boundaries into resource budgets. This ecological resource availability determines the global annual production of a resource that can be considered absolutely sustainable. The budgets can be managed like financial budgets, bringing absolute environmental limits one step closer to decision-makers.

Ecological resource potential

The ecological resource potential (ERP) method allows to calculate the amount of one material that can potentially be produced within Earth system boundaries, if no other anthropogenic activity would take place. It indicates the uppermost potential of one resource extracted, processed and disposed after use with a specific set of technologies and a defined probability of violating Earth system boundaries. This method is an adaption of the ecological resource availability (ERA) method, which calculates the amount of a resource that can be produced within an allocated share of the global boundaries, i.e. when considering all other anthropogenic activities. While more realistic, its allocation can be done in multiple ways and based on a variety of different objectives, which requires scenario modelling. The ERP method, in contrary, only requires information on environmental impacts from resource extraction, processing, and final disposal. The customization of the original ERA method comprises:•Omitting all steps for allocating global boundaries to single resources or resource segments.•Changing the calculation procedure so that ERP is calculated for each resource separately.

Invasive alien species as drivers in socio-ecological systems: local adaptations towards use of Lantana in Southern India

Lantana camara. L (hereafter Lantana) was first introduced by the British into India in 1807 as an ornamental plant. Since then the species has spread across the length and breadth of the country. Attempts to control Lantana in India have not been successful. In this study, we analysed the use of Lantana by local communities in southern India and identified the possible causes and consequences of its use through the use of a household survey of the socio-economic profile of the user and nonuser households and an analysis of the ecological history of the communities. Communities have been using Lantana for over 25–30 years and apparently such use was not prompted by external agencies. The characteristics of user and nonuser households were similar, except that Lantana users were more literate and had a greater number of occupations per household than nonusers. Per capita income was similar between user and nonuser groups. For nonuser groups, their main income sources were from trading (44 %), wage labour (32 %) and forest resources (23 %). In contrast, the Lantana user groups substituted their loss of income from forest resources (7 %) by income from Lantana (46 %). The ecological history revealed that Lantana was adopted as a resource at a time when it was increasing in the landscape and traditional bamboo resources were in decline because of overuse by commercial enterprises and mast flowering. This change in ecological resource availability prompted a major shift in livelihoods for some in the area.

Signatures of Ecological Resource Availability in the Animal and Plant Proteomes

Although substantial and ecologically significant differences in elemental composition are well documented for whole organisms, little is known about whether such differences extend to lower levels of biological organization, such as the elemental composition of major molecules. In a proteome-scale investigation of 9 plant genomes and 9 animal genomes, we find that the nitrogen (N) content of plant proteins is lower than that in animal proteins. Furthermore, protein N content declines with the intensity of gene expression for plants, whereas the N content of animal proteins shows no consistent pattern with expression. Additional analyses indicate that the differences in N content between plant and animal proteomes and in plant proteins as a function of gene expression cannot be attributed to protein size, GC content, gene function, or amino acid properties. These patterns suggest that ecophysiological selection has operated to conserve N in plants via decreased reliance on N-rich amino acids. This inference was supported by an analysis of conserved and variable sites indicating that the N content of plant amino acids coded by variable sites is similar to that of the sites conserved between plant and animal genomes and shows no association with expression level. In contrast, in animals, the N content of amino acids coded by variable sites is significantly higher than that for conserved sites, suggesting relaxation of selective constraints for N usage in the animal lineage. This constitutes the first evidence for an influence of environmental resource availability on proteomes of multicellular organisms.

Applications of using a landscape-scale model to quantify white-tailed deer habitat potential in Michigan, U.S.A.

The distribution and availability of ecological resources in a landscape can explain differences in deer population demographics. Therefore, to sustain white-tailed deer populations, it is important to manage vegetation communities rather than just deer numbers. Often, biologists determine deer habitat suitability and establish population goals by evaluating existing vegetation. However, because the distribution of habitat reflects differences in climate and geology, development of deer population management goals should be based on the ecological potential of habitat to support different deer demographics. Our objectives were to develop a spatially explicit landscape-scale model that quantifies deer habitat potential in Michigan and illustrate how well the model describes deer population demographics. We found a negative relationship between the spatial distribution of fall and winter food potential and antler beam diameters. Other habitat components such as spring and summer food may drive antler beam diameter distribution. Our model does indicate, however, that it is reasonable to establish different deer management goals with respect to variations in the potential of vegetation conditions to provide deer habitat. The modeling process can be used to model other habitat components, determine which components are most influential in driving demographic patterns, and subsequently be used to establish effective management goals.

Population and the Demise of Cheap Energy

Standard of living is determined in part by the availability of ecological resources, and in part by the availability of "cheap energy." The demise of cheap energy is likely to occur during the twenty-first century. Gradually, over this time, humans will be restricted to using renewable natural capital. Reliance on renewable energy sources will require a reduction in population to within the range of 1.5 to 3 billion people in order to maintain what most of us would regard as an adequate lifestyle. Attention is drawn to the need for nations to exercise sovereign responsibility.