**4. Description of the floristic-holistic method (FHM)**

This proposal combines several types of sampling in a single comprehensive methodology. This method combines the point intercept line with the Point Centered Quadrants Method [6] and the Pastoral Value Method (PVM) [2–4].

#### **Figure 2.**

*Location and use of the metal needle. Modified from [2, 3].*

For data collection in the field, the types of environments must be recognized, classifying the vegetation by its physiognomy and by the dominant aspects, highlighting those that make the greatest contribution to the total coverage.

The Floristic-Holistic Method (FHM) consists of randomly locating the first point of the transect, and the rest of the points are located on an imaginary line at a fixed distance. Each transect had 100 equidistant points, whose distance was equal to 3 paces (1 pace = 1 meter). To ensure a good census of vegetation, data collection is avoided near fences, roads, or areas disturbed by the passage of vehicles, or in patches that are not representative of the vegetation.

To perform the reading, a metal needle 1 m long and 5 mm in diameter is used. The needle is stuck in the ground at the height of the toe of the shoe (**Figure 2**) and vegetation records are taken along the needle, noting suitable forms for it.

To place the needle at each point, you look at the reference point, thus avoiding choosing where to place it.

All living plants are taken as the focus of observation, regardless of whether they are forage, ephemeral, or annual. Thus:


Due to the superposition of different biological forms in the vertical structure, one or more plant species can be recorded in the same reading.

*The Floristic-Holistic Method for Arid, Semiarid, and Subhumid Areas: A Tool… DOI: http://dx.doi.org/10.5772/intechopen.106226*

**Figure 3.** *Direct touch on perennial plant and a living portion of the plant. Modified from [2, 3].*

#### **Figure 4.**

*Direct contact of bare soil, mulch, rock, or erosion pavement. Modified from [2, 3].*

• If there is no direct contact with living plant species along the needle. And in the event that the direct contact of the needle is bare soil, topsoil (dead or decomposing plant material on the surface), rock (rocky outcrops or large clasts), or erosion pavement (high percentage of stones of different surface sizes), it is recorded with an "X" surrounded by a circle. Then, the closest plant in the four quadrants is observed, which one is noted (without circling the number of touches, since the touch is indirect) (**Figure 5**). The indirect touch is relieved only on living plants.

From the information obtained in each transect, the attributes of the soil and vegetation are summarized:

Bare or unvegetated ground: Sum of points where the needle directly touched bare ground, rock, topsoil, and other surface soil attributes.

#### **Figure 5.**

Dead plant material: Sum of points where the needle directly touched a dead plant in a living position or pieces of dead branches not incorporated into the soil.

Litter: Sum of points where the needle directly touched mulch or decomposing dead plant material incorporated into the soil (broken branches, leaves, seeds, remains of flowers, and fruits).

Coverage by species (CoSp): Number of points in which a species has been found (the closest plants are not included). Since the points are 100, the coverage can be expressed as a percentage. To facilitate its computation, the mark or number of touches of directly touched plants is circled on the spreadsheet.

Total relative plant cover (TRPC): Sum of the cover (Co) of plant species. It would be the number of points where the rod directly touched a living plant (closest plants are not included). Since the points are 100, the coverage can be expressed as a percentage. To facilitate its computation, the mark or number of touches of directly touched plants is circled on the spreadsheet.

Total absolute plant cover (TAPC): Sum of all the covers of the species.

Specific plant coverage (SPC—touches by species): Total number of contacts of the rod with a species (the number of touches that has been recorded for each species (direct touch) is added). Percentage expression of the relationship between the number of touches made to a species (TSp) and that of total touches (TT) made to all the species registered in the 100 sampled points: SPC = (TSp x 100)/TT.

For this point, it is recommended to follow the updated names of the species according to the catalog of vascular plants of the southern cone [7].

Cover by biological forms (CBF): Percentage of total cover or by species that correspond to the different biological forms (shrubs, herbs, grasses, trees, succulents, and thallophytes).

Cover by biological types: Percentage of total cover corresponding to the type of plant according to the classification of the large groups of plants (Bryophyta,

*The Floristic-Holistic Method for Arid, Semiarid, and Subhumid Areas: A Tool… DOI: http://dx.doi.org/10.5772/intechopen.106226*

Lycophyta, Monilophyta, Gymnosperms (Gnetophyta, Coniferophyta), angiosperms (Monocotyledons, Eudicots, Basal Angiosperms, Magnolides), fungi (Mucoromycota, Ascomycota, Basidiomycota, etc.), lichens.

With respect to monocotyledons, they can be grouped into gramineous and nongramineous monocots. As for lichens, the species itself, their growth form (crustaceans, foliose, and fruticulous), the type of thallus (homogeneous or heterogeneous structure), and/or the substrate in which they live (saxicolous, terrestrial, etc.) can be considered as corticultural, follicultural, or zoobiotic.

Coverage by biological status: Percentage of total coverage or by species that corresponds to the different types of status in plants (native nonendemic, endemic, introduced non-feral, native feral). At this point, the IUCN red list of treated species (https://www.iucnredlist.org/) and checklist of CITES species (https://checklist.cites. org/#/en) can be considered, as well as legislation national. In the case of Argentina, we used resolution 84/2010 (red list of endemic species of Argentina—https://www. argentina.gob.ar/normativa/nacional/resoluci%C3%B3n-84-2010-165,374) and resolution 109/2021 (list of invasive, potentially invasive, and cryptogenic exotic species https://www.argentina.gob.ar/normativa/nacional/resoluci%C3%B3n-109-2021- 348,718), both resolutions of the Ministry of Environment and Control of Sustainable Development of the Nation.

Coverage by biotype or type of life: Percentage of total coverage or by species that corresponds to the different types of plants (annuals, biennials, perennials, and multiennials).

Coverage by botanical families: Percentage of total coverage or by species that corresponds to the different botanical families (Alliaceae, Apiaceae, Asteraceae, Cactaceae, Fabaceae, Poaceae, and so on).

Coverage Raunkiaer biological forms: Percentage of total coverage or by species that correspond to the different life forms according to Raunkiaer [8]. This classification is based on the position of the shoot buds, and this is an adaptive character because growth depends on the buds once the adverse season is over. Five main categories are distinguished in this classification:

1.Therophytes or annual plants: Spend the adverse period in the seed stage.

2.Hydrophytes: Shoot buds in the water (they can be floating or fixed in the mud).

3.Geophytes or cryptophytes: Vegetative buds are below ground level.

4.Hemicryptophytes: Vegetative buds are found at surface level.


7.Epiphytes: Plants that live on other plants.

They can also be quantified according to adaptation (xerophytes, mesophytes, hydrophytes, and so on) and organ modifications (plants with rhizomes, tubers, bulbs, foliar thorns, cauline thorns, napiform roots, and so on).

Plant-specific density: Number of plants per hectare. Number of times a plant appears every 100 direct hits on a 100 meters transect. It is calculated from the number of plants recorded in the transect and considering the length of each transect (100 meters).

Shanon-Weaver Diversity Index: It is calculated from the proportions (p *<sup>i</sup>*) of each species (*i*) in the total sample of individuals. It is calculated using the following formula: H = Σ p *<sup>i</sup>* log <sup>e</sup> p *<sup>i</sup>*. Where H is the logarithmic measure of diversity, and p*<sup>i</sup>* = proportion of individuals of species *i* with respect to the total number of individuals (i.e., the relative abundance of species *i*). It can be said that the Shannon diversity index measures (the reciprocal of) the probability of selecting all the species in the proportion that they exist in the population; that is, it measures the probability that a sample selected at random from an infinitely contains exactly n <sup>1</sup> individuals of species 1, n <sup>2</sup> of species 2, … and n <sup>s</sup> individuals of species S [9–11].

The diversity value (H) generally varies between 1.5 and 3.5 and rarely exceeds 4.5 [12]. It is worth mentioning that the maximum diversity (Hma x = lnS) is reached when all species are equally present. On the other hand, the value of H is bounded between 0 and ln(s), which tends to zero in communities with little diversity and is equal to the logarithm of the species richness in communities with maximum equality [13].

Equity: It allows knowing the degree of regularity with which individuals are distributed among species. It is calculated using the following formula: E = H/ln S.

Where H is the diversity index and S is the number of species (specific richness). Evenness approaches zero when one species dominates all others in the community and approaches 1 when all species share similar abundances [13].

Wealth: Number of recorded species.

Species Quality index (SQI): Specific quality index that has been assigned to each species as a result of the evaluation of its degree of acceptability by livestock, the period in which it is used, and its nutritional value (in Ref. to [2, 3]). But many other species surveyed by our HTW team based on more than 25 years of field observation in different areas with different conditions and different levels of degradation are also recorded. **Table 2** presents a list of species with their SQI.

Pastoral Value (PV): The value of the pastoral value determines the amount of forage available at the livestock level. It is calculated based on its floristic composition, and the quality and quantity of the species that compose it (in the census considering only living plants and those of forage value).

The following formula was used: PV = (0.2 x Σ (Tsp x SSI) x TAPC)/TT.

where TSp = Touches per species, SQI = Specific Quality Index, TAPC = Total absolute plant cover, TT = Total Touches. The constant 0.2 is used to keep the range of pastoral values between 0 and 100. Note: Once the census calculations have been carried out, the pastoral values (PV) are obtained per transect carried out. Subsequently, the average PV (PVp) is calculated for each surveyed environment.

Use Factor (UF): The concept of use factor corresponds to the percentage of available forage that can be grazed by livestock to allow sustainable production over time. This factor varies with the type of vegetation in each area, the climatic conditions, and the vigor of the most important forage plant species. These values for each environment were developed by researchers from the National Institute of Agricultural Technology (INTA Trelew, Chubut, Argentina), according to what was

