**3.2 Results and discussion**

Since the rise of agriculturally based societies in the Mediterranean, and concomitant population growth in coastal areas, humans have gradually generated irreversible impacts on natural biotic resources. The introduction of agricultural practices and human-induced fires in northern Istria is dated to 5000 BP [4]. The cultivated species were mostly cereals (*Secale*, *Hordeum*, *Avena*, and *Triticum*), the same genus found in the Mirna region (**Figure 3**). The succession of agropastoral activities can be determined here, with cereals (about 3000 years BP), olive growing, viticulture, and orchards (about 2000 years BP) (**Figure 3**). Optima appear in Medieval and Roman eras.

The periodicity of agropastoral activities was investigated using a wavelet analysis, highlighting the long-term trends versus storm surges with a 950-year period [2]. This suggests that low storm activity and enhanced freshwater inputs in the delta have favored arboriculture and agriculture. Conversely, periods of higher storm surges, which generated the intrusion of saline water into the freshwater-fed plains and into the groundwater table, led to severe agricultural losses. The comparison of the two signals, fitted to a 950-year filter, shows that, at a millennial time scale, anthropogenic activities and storminess are in antiphase [2]. In addition, we can observe that the most prosperous periods of agropastoral activities correspond to the optima of the Roman civilization and the Medieval era. The abandonment of

**Figure 2.**

*Examples of botanical micro- and macro-remains observed by optical microscopy or by scanning electronic microscopy.*

#### **Figure 3.**

*Reconstruction of agropastoral activities from Mirna region during 4500 years with the help of isotopic 14C datation and palynological determinations (modified from [2]).*

**75**

*Geochemical Methods to Assess Agriculture Sustainability*

all agricultural activities around 1650 years BC can be ascribed to the consequences of the major volcanic eruption of Santorini. The ends of the prosperous periods can be related to the invasions of the northern peoples (the so-called Dark Ages) and war periods. A maximum is indeed observed at 3500 BP, followed by a minimum at 3200 BP. This latter minimum can be ascribed to the collapse of Bronze Age civiliza-

*Position of intensive paleo-agropastoral activities (in gray) from Mirna core placed on the 6000 years BP temperature variation reconstructed from ice cores drilled in Central Greenland. For the detail of datation of* 

By comparison with the curve of temperature over 6000 years BP building up from ice cores drilled in the center of Greenland, the results show that the agropas-

For the medium-time investigations, the consequences of intensive agriculture of the last 60 years have been studied in the irrigated grasslands in Crau's area (hay

of the territory is occupied by a natural semiarid steppe, named "coussoul," and, in another part, by irrigated grasslands and orchards. Thanks to Adam de Craponne, a sixteenth-century engineer, a first irrigation canal was built up, and the irrigation network extended until the nineteenth century. The network supports the production of the Crau hay with a protected designation of origin, which is exported all over the world to feed racehorses, the Sisteron lamb, and the Arles Merinos sheep, which are

at the south of Alpilles mountains. A part

toral optima of Mirna's core correspond also to thermal optima (**Figure 4**).

**4. Investigations of medium-time period (60 years) in intensive** 

production with COP label) in southeast of France.

The Crau's area covers up to 600 km2

*DOI: http://dx.doi.org/10.5772/intechopen.85336*

tion near 1177 BC = 3127 BP [5].

**agriculture**

**Figure 4.**

*Mirna's core, see Figure 3.*

**4.1 Materials and methods**

*Geochemical Methods to Assess Agriculture Sustainability DOI: http://dx.doi.org/10.5772/intechopen.85336*

#### **Figure 4.**

*Applied Geochemistry with Case Studies on Geological Formations, Exploration Techniques…*

*Examples of botanical micro- and macro-remains observed by optical microscopy or by scanning electronic* 

*Reconstruction of agropastoral activities from Mirna region during 4500 years with the help of isotopic 14C* 

*datation and palynological determinations (modified from [2]).*

**74**

**Figure 3.**

**Figure 2.**

*microscopy.*

*Position of intensive paleo-agropastoral activities (in gray) from Mirna core placed on the 6000 years BP temperature variation reconstructed from ice cores drilled in Central Greenland. For the detail of datation of Mirna's core, see Figure 3.*

all agricultural activities around 1650 years BC can be ascribed to the consequences of the major volcanic eruption of Santorini. The ends of the prosperous periods can be related to the invasions of the northern peoples (the so-called Dark Ages) and war periods. A maximum is indeed observed at 3500 BP, followed by a minimum at 3200 BP. This latter minimum can be ascribed to the collapse of Bronze Age civilization near 1177 BC = 3127 BP [5].

By comparison with the curve of temperature over 6000 years BP building up from ice cores drilled in the center of Greenland, the results show that the agropastoral optima of Mirna's core correspond also to thermal optima (**Figure 4**).
