Landscape unit

In a chemically disturbed landscape unit, exposure concentrations, as well as population and community responses, may show clear spatial patterns. Assessing risks at a landscape scale (e.g., watershed), however, requires the development of a... 

It is clear that an accurate exposure prediction at the landscape level requires models calibrated and validated for the landscape unit of interest and that the input parameters used have a high precision and accuracy for the area of interest (see Section 1.7 in Chapter 1). However, in a prospective risk assessment for new chemicals not yet placed on the market, chemical monitoring data are not yet available, and exposure predictions at the landscape level may be characterized by a relatively high uncertainty because the scale and intensity of the use of these chemicals are not... 

If, through a proper landscape analysis, a realistic combination of multiple stressors is identified, food-web models may be used to predict and extrapolate their ecological effects to relevant ecosystems of the landscape unit of concern. An overview of models that can be used for the integrated assessment of eutrophication and organic contaminants in aquatic ecosystems is provided by Koelmans et al. (2001). Examples of aquatic food-web models that can be used or adapted to predict effects of multiple stressors are IFEM (Bartell et al. 1988), AQUATOX (Park 1999), and C-COSM (Traas 2004). 

We can apply differential calculus and the law of mass conservation to derive a conceptual model for carbon dynamics in a forested landscape unit where carbon is sequestered in either biomass (alive or dead but identifiable) and soil carbon (see appendix for derivation). 

Most research focuses on the time rate of change of these stocks, stratified by vegetation type. Using the chain rule (see appendix), we can derive the following relationship where the time rate of change of carbon in the landscape unit is a function of four groups of fluxes. These fluxes are listed as a-d for each of the vegetation types in the landscape unit ... 

For the purpose of this chapter, we will first examine how human activities affect these fluxes, estimating the relative importance of the various anthropogenic fluxes of equation (2) for Brazilian Amazonia the landscape unit for our estimates is therefore the entire original forested region (Table 8.2). Then, we will demonstrate how extractive reserves and extractivist activities are related to these broader anthropogenical-ly induced fluxes. 

We can apply the rules of differentiation to derive a model of the change in carbon content of a landscape unit covered by vegetation types of differing carbon contents. Equation (A-1) expresses the carbon content of the unit as the sum of carbon in the biomass and in the soil of the vegetation types ... 

The first question is which ones among a disparate population of n cases (landscape units) have consistency of expression (concordance) relative to a suite of p indicators. Subsets of the cases having consistent expression are subject to direct comparative ordering to address further questions. 

How can cases (landscape units) be recognized that are severely degraded in all relevant respects to the degree that preservation and protection concerns are effectively absent. 

Our primary focus here is on these questions where partial or incomplete orderings are directly informative to conservation, remediation, or allocation issues of environmental management. Biodiversity and ecosystem health are multifaceted concerns that are most readily and objectively approached through suites of indicators. Prioritization of landscape units in these regards is also intrinsically complex. If a subset of indicators is essentially concordant across all cases of observation, then the indicators in the (sub)set are also substantially redundant. On the other hand, indicators representing largely independent dimensions of biodiversity or ecosystem health will almost necessarily complicate prioritization processes because there will be less consistency in how the respective landscape units reflect... 

Therefore, the focus shifts from indicator to landscape unit (watershed in this case). Statistics are computed on the set of rank values for each landscape unit (watershed). Statistics needed for the present operation are minimum rank, maximum rank, and median rank. These become three derived observational variables for each landscape unit (watershed). Given these preparatory computations, the operations for rank range sequencing are as follows ... 

Fig. 6. Correlation between the BTC index (Meal/m2/yr Y axis) and the human habitat in about 50 case study of landscape units in central Europe (X axis HH as %LU). Note the impxMtance to utilise the equation (12) in the clinical diagnosis of the ecological state of the landscape.

In a landscape or in its subsystems (i.e. Landscape Units) the main transformation processes depend on the hierarchical structuring of an ecological system and its non-equilibrium thermodynamics, metastabiHty, coevolution, evolutionary changes and ecological reproduction. Let us review the main steps, essential to revise later some basic concepts of vegetation science ... 

The below presented frame protocol uses a parametric standard form (a proper one for each type of vegetation) for the analysis and evaluation of a vegetated tessera. It is very helpful in the definition of the so called "normal state" for each sp>ecific typ>e of tessera. Remember that landscape bionomics follows a clinical-diagnostic method and its main goal concern the evaluation of the healthy state of a landscape unit, in which the vegetation coenosis play a central role. 

The Mori municipality is about 35 sq.Km, 53% covered by forest. It consists of 4 Landscape Units (LU) presenting different landscape types (Fig. 9) ... 

Fig. 9. The localization of the municipality of Mori, in the Southern part of Trentino, near the upper Garda Lake, and (right) the division of the territory in 4 landscape units of (1) Mori-Talpina (violet), (2) Loppao (pank), (3) val Gresta (green) and (4) mount Biaena (pale blue).

The results from the survey of 13 forested tesserae in the LU1 of Mori-Talpina are shown in table 5, where pB measure the plant biomass above ground BTC is the biological territorial capacity of vegetation (Mcal/mVyear) Q represent the four ecological qualities of the tessera (Ect = ecocenotope, LU = landscape unit, Ts = tessera, pB = plant biomass, B = % of coniferous species, BTC maturity threshold, 85% of the model curve). 

Table 5. Landscape Unit 1 MORI forested area Km 3,29 (27,7% LU)...

Fig. 13. The EUenberg indexes resulted from the analysis of the species of the Mori-Talpina Landscape Unit have been compared with 2 case study, the first in Menaggio (Pre-Alpine conditions), the second in ZoagU (Mediterranean conditions). L= Light, T = temperature, C = continentality, H = humidity, R = soil reaction, N = soil nutrients.

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