170
for the species, that is, seedlings with diameter at collar level > 2.5 mm, shoot/root
biomass ratio < 2, and height/diameter ratio < 54 (Urretavizcaya et al. 2016).
Either for restoration or production purposes, the species is expected to be
planted within its natural range. In this regard, the definition of provenance regions
was taken in advantage to consider them as breeding zones. According to White
et al. (2007), a breeding zone is a distinct area with some environmental variation
for which an improved genetic variety of a forestry species is being developed. This
critical decision is foundational for a well-planned tree improvement program. In
fact, each breeding zone should have a separate improvement program with its own
distinct base, selected, breeding, and production populations.
With a two-decade experience of genetic research in the Patagonian cypress, the
Instituto Nacional de Tecnología Agropecuaria (INTA) formally began a lowintensity breeding program for the species in 2012. Although the vegetative propagation of the species is operatively possible through scion grafting (but not by stem
rooting, Aparicio et al. 2009), thus opening the way for the installation of clonal
seed orchards, the mass selection of individuals in the forest seems hardly feasible
because they are commonly uneven-aged and frequently mixed with Nothofagus
dombeyi in the best quality sites. Consequently, the improvement strategy focused
on the establishment of progeny seed orchards (PSO) and indeed one for each of the
defined provenance regions. So far, we have achieved to install three PSOs with
cypress in Argentina. The first one, corresponding to the South Provenance Region
(PR S), was planted in 2015 at the Trevelin Forest Station of INTA (43° 06′ 51″ S;
71° 33′ 53″ W; 455 m asl), occupies 2/3 ha, and contains 92 open-pollinated families from four natural populations (N = 1336). In the same year, a complementary
progeny test including the same mother trees was installed in Epuyén Forest Reserve
belonging to the Province of Chubut. The second PSO was established in 2017 in
Junín de los Andes (39° 57′ 27″ S; 71° 05′ 09″ W; 810 m asl), within a land property
of CORFONE S.A., the most important forestry and industrial wood company in
Patagonia (Fig. 6.9). This PSO corresponds to the North Low Provenance Region
(PR NL) and is composed of the progeny of 65 mother trees from 5 natural populations (N = 634; area = 1/3 ha). We installed the third PSO, corresponding to the
Central Provenance Region (PR C), in 2018 at General San Martín Forest Station of
INTA (41° 59′ 46″ S; 71° 31′ 45″ W; 400 m asl). It occupies one half hectare and
contains the open-pollinated progeny of 66 trees from three natural populations
(N = 644). The saplings have not yet reached 1 m high, so we are still far from the
genetic selection, which is expected to begin in 2030.
While the seed orchards mature, seeds continue being collected from wild stands.
In this regard, three seed production areas (SPA) were defined for the species in
Argentina and registered in the National Institute of Seeds (INASE). They are (1)
Cañada Molina, 50 ha (37° 07′ 41″ S; 70° 36′ 22″ W; 1400 m asl); (2) Loma del
Medio, 32 ha (41° 56′ 51″ S; 71° 33′ 10″ W; 470 m asl); and (3) INTA Trevelin,
46 ha (43° 06′ 16″ S; 71° 31′ 50″ W; 430 m asl).
Finally, two provenance tests of the species were installed in 2015 and 2016. The
first one, representing 23 Argentine provenances (N = 2292), was established in
General San Martín Forest Station of INTA and the second, which represents 18 of
A. G. Aparicio and M. J. Pastorino
for the species, that is, seedlings with diameter at collar level > 2.5 mm, shoot/root
biomass ratio < 2, and height/diameter ratio < 54 (Urretavizcaya et al. 2016).
Either for restoration or production purposes, the species is expected to be
planted within its natural range. In this regard, the definition of provenance regions
was taken in advantage to consider them as breeding zones. According to White
et al. (2007), a breeding zone is a distinct area with some environmental variation
for which an improved genetic variety of a forestry species is being developed. This
critical decision is foundational for a well-planned tree improvement program. In
fact, each breeding zone should have a separate improvement program with its own
distinct base, selected, breeding, and production populations.
With a two-decade experience of genetic research in the Patagonian cypress, the
Instituto Nacional de Tecnología Agropecuaria (INTA) formally began a lowintensity breeding program for the species in 2012. Although the vegetative propagation of the species is operatively possible through scion grafting (but not by stem
rooting, Aparicio et al. 2009), thus opening the way for the installation of clonal
seed orchards, the mass selection of individuals in the forest seems hardly feasible
because they are commonly uneven-aged and frequently mixed with Nothofagus
dombeyi in the best quality sites. Consequently, the improvement strategy focused
on the establishment of progeny seed orchards (PSO) and indeed one for each of the
defined provenance regions. So far, we have achieved to install three PSOs with
cypress in Argentina. The first one, corresponding to the South Provenance Region
(PR S), was planted in 2015 at the Trevelin Forest Station of INTA (43° 06′ 51″ S;
71° 33′ 53″ W; 455 m asl), occupies 2/3 ha, and contains 92 open-pollinated families from four natural populations (N = 1336). In the same year, a complementary
progeny test including the same mother trees was installed in Epuyén Forest Reserve
belonging to the Province of Chubut. The second PSO was established in 2017 in
Junín de los Andes (39° 57′ 27″ S; 71° 05′ 09″ W; 810 m asl), within a land property
of CORFONE S.A., the most important forestry and industrial wood company in
Patagonia (Fig. 6.9). This PSO corresponds to the North Low Provenance Region
(PR NL) and is composed of the progeny of 65 mother trees from 5 natural populations (N = 634; area = 1/3 ha). We installed the third PSO, corresponding to the
Central Provenance Region (PR C), in 2018 at General San Martín Forest Station of
INTA (41° 59′ 46″ S; 71° 31′ 45″ W; 400 m asl). It occupies one half hectare and
contains the open-pollinated progeny of 66 trees from three natural populations
(N = 644). The saplings have not yet reached 1 m high, so we are still far from the
genetic selection, which is expected to begin in 2030.
While the seed orchards mature, seeds continue being collected from wild stands.
In this regard, three seed production areas (SPA) were defined for the species in
Argentina and registered in the National Institute of Seeds (INASE). They are (1)
Cañada Molina, 50 ha (37° 07′ 41″ S; 70° 36′ 22″ W; 1400 m asl); (2) Loma del
Medio, 32 ha (41° 56′ 51″ S; 71° 33′ 10″ W; 470 m asl); and (3) INTA Trevelin,
46 ha (43° 06′ 16″ S; 71° 31′ 50″ W; 430 m asl).
Finally, two provenance tests of the species were installed in 2015 and 2016. The
first one, representing 23 Argentine provenances (N = 2292), was established in
General San Martín Forest Station of INTA and the second, which represents 18 of
A. G. Aparicio and M. J. Pastorino