Changes in Meadow Phenology in Response to Grazing Management at Multiple Scales of Measurement

Riparian and ground-water dependent ecosystems found in the Great Basin of North America are heavily utilized by livestock and wildlife throughout the year. Due to this constant pressure, grazing can be a major influence on many groundwater dependent resources. It is important for land managers to understand how intensity and timing of grazing affect the temporal availability of these commodities (i.e., biodiversity, water filtration, forage, habitat). Shifts in forage or water availability could potentially be harmful for fauna that rely on them at specific times of the year. Seven meadow communities, each consisting of three distinct vegetative communities, were grazed at three intensities to determine the relationship between grazing management and phenological timing of vegetation. The agreement of on-the-ground measurements, near-surface digital cameras (phenocams), and satellite-based indices of greenness was examined for a two-year period (2019–2020) over these grazing and vegetative community gradients. Field determined phenology, phenocam Green Chromatic Coordinate (GCC), and Landsat Normalized Difference Vegetation Index (NDVI) were all highly correlated and the relationship did not change across the treatments. Timing of growth varied in these ecosystems depending on yearly precipitation and vegetative type. Communities dominated by mesic sedges had growing seasons which stopped earlier in the year. Heavier grazing regimes, however, did not equate to significant changes in growing season. Ultimately, shifts in phenology occurred and were successfully monitored at various spatial and temporal scales.

The Scientific Basis of the Target Plant Concept: An Overview

Reforestation and restoration using nursery-produced seedlings is often the most reliable way to ensure successful establishment and rapid growth of native plants. Plant establishment success—that is, the ability for the plant to develop within a set period of time with minimal further interventions needed—depends greatly on decisions made prior to planting, and yet nursery-grown plants are often produced independently of considering the range of stressors encountered after nursery production. The optimal plant or seedling will vary greatly with species and site (depending on edaphic and environmental conditions), and in having the biological capacity to withstand human and wildlife pressures placed upon vegetative communities. However, when nursery production strategies incorporate knowledge of genetic variability, address limiting factors, and include potential mitigating measures, meeting the objectives of the planting project—be it reforestation or restoration—becomes more likely. The Target Plant Concept (TPC) is an effective framework for defining, producing, and handling seedlings and other types of plant material based on specific characteristics suited to a given site. These characteristics are often scientifically derived from testing factors that are linked to outplanting success, such as seedling morphology and physiology, genetic source, and capacity to overcome limiting factors on outplanting sites. This article briefly summarizes the current knowledge drawn from existing literature for each component of the TPC framework, thereby helping land managers and scientists to meet objectives and accelerate reforestation and restoration trajectories.

Influence of Beef Cattle Stocking Density on Utilization of Vegetative Communities in a Late-Spring, Early-Summer Native Bunchgrass Prairie

This study evaluated the influence of cattle stocking density on the use of botanical communities on a native bunchgrass prairie. In each of two years, 192 cow-calf pairs and 48 yearling heifers were randomly selected for the following grazing treatments: 1) control, no livestock grazing; 2) low stocking, 0.36 animal units (AU) ∙ ha-1; 3) moderate stocking, 0.72 AU ∙ ha-1; and 4) high stocking, 1.08 AU ∙ ha-1 for a 42-day grazing period. Thirty-six monitoring sites were established uniformly along a grid in each paddock. Standing crop and relative preference data for cattle collected from the treatment area were used to develop the following vegetation community classifications: 1) > 20% introduced; 2) > 40% native bunchgrass with > 50% Idaho fescue (Festuca idahoensis); 3) > 40% native bunch grass with < 50% Idaho fescue; 4) > 50% Forb; and 5) other. Utilization for each community type was collected at the end of the grazing period. High stocking density paddocks had higher utilization across all vegetation classifications compared to other stocking densities (P ≤ 0.04). Moderate stocking density paddocks were utilized 11.5% more than low paddocks, however, utilization of introduced vegetative communities, Idaho fescue dominated bunchgrass communities, and forb dominated communities did not differ in use (P ≥ 0.13). Use of monitoring to actively adjust stocking densities based on differential community utilization may improve the sustainable grazing of sensitive communities because conventional stocking rate calculations based on total productivity do not account for the selective grazing behavior of cattle.

NIGHTSHADE BLACK – SOLANUM NIGRUM L. (SOLANACEAE) ON SALINE HABITATS OF THE SOUTHEAST EUROPE

One of the negative florogenesis trends is the diversification of flora with alien species, which goes parallelly with insularization of natural vegetation cover. They alter the structure of ecosystems, reduce their productivity, threaten the diversity and genetic integrity of natural flora by integration into natural communities and competition with native flora species. One of alien species of Solanaceae Juss family is black nightshade (Solanum nigrum L.) – a poisonous species of Mediterranean origin, with a Eurasian secondary area; unintentionally introduced alien species (xenophyte), naturalizing in secondary habitats (epecophyte), mesophyte, heliophyte, zoochor, naturalizing predominantly in more or less disturbed vegetative communities of South-Eastern Europe. This species is also found on salted soils, where it is registered in the communities of associations Cichorio-Lactucetum serriolae Golub et Mirkin 1986, Atriplici aucheri-Tamaricetum ramosissimae Golub et al. 1998 (subassociations A.au.-T.r. althaeetosum Golub et al. 1998, A.au.-T.r. cannabietosum Golub et al. 1998), Polygono-Aeluropodetum pungentis Golub et Mirkin 1986 and Suaedo-Petrosimonietum Golub 1986 (variant Glycyrrhiza glabra). These associations can occur on soil with a wide range of salinization degree – both on soils with weak- and high- salinity — but Solanum nigrum does not have much difference in its presence in their communities depending on this factor. The species is characterized by a weak introduction in cenoses of saline habitats – it is rare and has low abundance level.

Invasions of Bidens frondosa L. (Asteraceae) in communities of saline soils of south-east Europe

Bidens frondosa is an invasive xenophyte which is naturalized in vegetative communities on the territory of the Southeast of Europe. The natural area of B.frondosa is in the North America. The secondary one is on the territory of Eurasia, here B.frondosa forces out native B.tripartita that is explained by competitive superiority of the North American species on growth rates and seed efficiency on soils of different fertility and water regime. In the secondary area in Eurasia B.frondosa grows on banks of reservoirs and water currents as well as on other damp habitats (including disturbed ones) often in large quantities. This species is also found on saline soils of the European Southeast. It is registered in communities of association Atriplici aucheri-Tamaricetum ramosissimae Golub et al. 1998 belonging to class Nerio-Tamaricetea Br.-Bl. et Bols 1958 order Tamaricetalia ramosissimae Golub in Barmin 2001 alliance Elytrigio repentis-Tamaricion ramosissimae Golub in Barmin 2001, in one of its subassociations A.au.-T.r. althaeetosum Golub et al. 1998, but there B.frondosa is the diagnostic taxon as well as the constant species that is met in all of its described coenosis.

Comparing the efficacy of linear programming models I and II for spatial strategic forest management

Contemporary strategic forest management goals have become increasingly complex in spatial definition and scale. For example, the Canadian Council of Forest Ministers Criteria and Indicators (CCFM C&I) includes metrics that are expressed at multiple levels of spatial resolution such as ecodistricts, watersheds, and vegetative communities. Supporting these criteria with aspatial models is sometimes difficult, and results are often not transferable to the actual forest. We describe a spatial Model I stand and prescription-based strategic forest planning model that includes spatial metrics in a realistic sized problem. We compare its formulation, capabilities, and computational efficiency with a Model II formulation using a case study on Nova Scotia’s Crown Central Forest. We demonstrate that the spatial Model I is better suited to support strategic forest management when spatial criteria are included.