300
(Contreras et al. 2011; Risio et al. 2014), thus raising the deforestation area used for
crops and shifting westward the agricultural frontier (Barbosa 2005).
Caldén is a heliophilous and deciduous tree, 12–15 m high, with a superficial
radical system. The flowers that are arranged in spikes are hermaphroditic,
actinomorphic and yellow (Burkart 1976). Flowering period occurs in spring but
can be aborted by late frosts or rains. A second smaller flowering can happen in
January. The fruit is an indehiscent helical legume containing up to 35 oval seeds,
and the fructification occurs at the end of December and January (Steibel 2003; Lell
2004). It is a diploid species with a somatic number of 2n = 28 and small chromosomes (Burkart 1976). The dispersion of the Caldén is mostly endozoic, although it
also sprouts vegetatively from the stump (Tortorelli 1956; Boyero 1985; Lell 2004).
The bark is persistent and resistant to fire. Their specimens can be very long-lived,
reaching up to 318 years (Scarone et al. 2000). Caldén has a high-quality wood,
used for furniture, parquet flooring and fuel with a high calorific value. It has a density of 0.750 kg/dm
3
in the dry state (Bogino 2006). The official statistics registered
in 2017 the production in Argentina of 229 tonne of roundwood, 722 tonne of poles,
22 tonne of charcoal and 58,504 tonne of firewood (SGAyDS 2019). In addition, the
fruit is a fodder highly desired by native fauna and livestock, because of its carbohydrates wealth. Nevertheless, their inter-annual production and their spatial distribution are very variable (Menvielle and Hernandez 1985; Risio et al. 2016). As a
heliophyte species, open areas favour its growth (Velasco et al. 2018), and it
responds vigorously to early thinning treatments and pruning (Amieva 2013). Mean
radial growth values estimations of 2.47 to 3.47 mm.year
−1
are cited in the Province
of San Luis (Bogino and Villalba 2008) and 1.88 to 4.04 mm.year
−1
in the Province
of La Pampa (Peinetti et al. 1994; Velasco et al. 2018). Silvicultural rotation is
between 60 and 100 years in natural forests without management (Bogino and
Villalba 2008), and the natural regeneration period has been calculated as 4 years in
unperturbed sites under optimal light conditions.
Gonopterodendron sarmientoi (Lorentz ex Griseb.) A.C. Godoy-Bürki (syn.
Bulnesia sarmientoi Lorentz ex Griseb.) (Zygophyllaceae) is a ~ 20 m high tree
distributed in Central-Northern Argentina, South-Eastern Bolivia, Western Paraguay
and marginally in south-western Brazil (Zuloaga et al. 2008; Waller et al. 2012) (see
Fig. 11.7). This species, known as “palo santo”, occurs mainly in semiarid areas
(Dry Chaco), under strong seasonality conditions; few natural populations of the
species were found marginally in the ecotone with humid climate, such as in
Chiquitano Dry Forest, the Pantanal or the Humid Chaco. Across its distribution
range, the average annual precipitation varies from 500 to 1200 mm and the average
annual temperature from 22 to 26 °C. The species is associated with temporarily
floodable soils with high clay content (Adamoli et al. 1972), particularly in the forests where palo santo is dominant (called “palosantales”), such as in those around
the Pilcomayo and Bermejo rivers.
Regarding the structure and population dynamics of palosantales, G. sarmientoi
trees (Fig. 11.4) show a diametric distribution with a preponderance of individuals
in the lower classes (diameter <20 cm) being the species density around 286 adult
trees/ha. In forests where the species does not dominate, it co-exists with typical
C. Pometti et al.
(Contreras et al. 2011; Risio et al. 2014), thus raising the deforestation area used for
crops and shifting westward the agricultural frontier (Barbosa 2005).
Caldén is a heliophilous and deciduous tree, 12–15 m high, with a superficial
radical system. The flowers that are arranged in spikes are hermaphroditic,
actinomorphic and yellow (Burkart 1976). Flowering period occurs in spring but
can be aborted by late frosts or rains. A second smaller flowering can happen in
January. The fruit is an indehiscent helical legume containing up to 35 oval seeds,
and the fructification occurs at the end of December and January (Steibel 2003; Lell
2004). It is a diploid species with a somatic number of 2n = 28 and small chromosomes (Burkart 1976). The dispersion of the Caldén is mostly endozoic, although it
also sprouts vegetatively from the stump (Tortorelli 1956; Boyero 1985; Lell 2004).
The bark is persistent and resistant to fire. Their specimens can be very long-lived,
reaching up to 318 years (Scarone et al. 2000). Caldén has a high-quality wood,
used for furniture, parquet flooring and fuel with a high calorific value. It has a density of 0.750 kg/dm
3
in the dry state (Bogino 2006). The official statistics registered
in 2017 the production in Argentina of 229 tonne of roundwood, 722 tonne of poles,
22 tonne of charcoal and 58,504 tonne of firewood (SGAyDS 2019). In addition, the
fruit is a fodder highly desired by native fauna and livestock, because of its carbohydrates wealth. Nevertheless, their inter-annual production and their spatial distribution are very variable (Menvielle and Hernandez 1985; Risio et al. 2016). As a
heliophyte species, open areas favour its growth (Velasco et al. 2018), and it
responds vigorously to early thinning treatments and pruning (Amieva 2013). Mean
radial growth values estimations of 2.47 to 3.47 mm.year
−1
are cited in the Province
of San Luis (Bogino and Villalba 2008) and 1.88 to 4.04 mm.year
−1
in the Province
of La Pampa (Peinetti et al. 1994; Velasco et al. 2018). Silvicultural rotation is
between 60 and 100 years in natural forests without management (Bogino and
Villalba 2008), and the natural regeneration period has been calculated as 4 years in
unperturbed sites under optimal light conditions.
Gonopterodendron sarmientoi (Lorentz ex Griseb.) A.C. Godoy-Bürki (syn.
Bulnesia sarmientoi Lorentz ex Griseb.) (Zygophyllaceae) is a ~ 20 m high tree
distributed in Central-Northern Argentina, South-Eastern Bolivia, Western Paraguay
and marginally in south-western Brazil (Zuloaga et al. 2008; Waller et al. 2012) (see
Fig. 11.7). This species, known as “palo santo”, occurs mainly in semiarid areas
(Dry Chaco), under strong seasonality conditions; few natural populations of the
species were found marginally in the ecotone with humid climate, such as in
Chiquitano Dry Forest, the Pantanal or the Humid Chaco. Across its distribution
range, the average annual precipitation varies from 500 to 1200 mm and the average
annual temperature from 22 to 26 °C. The species is associated with temporarily
floodable soils with high clay content (Adamoli et al. 1972), particularly in the forests where palo santo is dominant (called “palosantales”), such as in those around
the Pilcomayo and Bermejo rivers.
Regarding the structure and population dynamics of palosantales, G. sarmientoi
trees (Fig. 11.4) show a diametric distribution with a preponderance of individuals
in the lower classes (diameter <20 cm) being the species density around 286 adult
trees/ha. In forests where the species does not dominate, it co-exists with typical
C. Pometti et al.