Review of the Performance and Suitability of Pinus caribaea in Vietnam potx

Data up to 25 years after planting are presented from a total of 17 trials, planted on sites in the four major bio-geographic regions of Vietnam that are most promising for the establish

Review of the Performance and Suitability of Pinus caribaea in

Vietnam

Mark J Dieters1, Ha Huy Thinh2,Phan Thanh Huong2, and Huynh Duc Nhan3

October 2006

Report prepared for CARD project 033/05VIE: Field evaluation and advanced vegetative

mass-propagation technology for scaling up high-value plantations of Pinus caribaea and

related hybrids in Vietnam (Project Output 1.1)

Summary

Pinus caribaea was first planted in Vietnam in 1963 Since that time, this species has been

evaluated on potential sites throughout Vietnam As part of CARD project 033/05VIE, many

of the trials involving P caribaea were inspected and relevant trials were remeasured in early 2006 This report summarizes the performance of P caribaea in trials established since

1976 by the Forest Research Centre in Phu Tho and the Research Centre for Forest Tree Improvement in Hanoi

Summary data collated from various sources and newly collected data were analysed in a manner which would allow direct comparison to previous trial results Data up to 25 years after planting are presented from a total of 17 trials, planted on sites in the four major bio-geographic regions of Vietnam that are most promising for the establishment pine plantations – northern, central, central highlands, and southern Vietnam These trial results

clearly demonstrate the superior growth capacity of P caribaea over P kesiya, P merkusii and P massoniana

P caribaea var hondurensis (PCH)demonstrated great adaptability to a wide range of sites from northern to southern Vietnam, with relatively little provenance variation observed amongst those provenances evaluated However, it appears that the provenances of var

hondurensis tested in Vietnam are likely to have been selected based on results in

international provenance trials; all tested provenances ranked well in the Oxford and/or

CAMCORE series of provenance trials Only a limited sample of P caribaea derived from the Bahamas (i.e P caribaea var bahamensis, PCB) was evaluated; however, in trials located in northern Vietnam, growth of PCB was consistently good in comparison to PCH or other species Further, this variety is also likely to provide enhanced stem form and greater resistance to some insect pests than PCH Performance of the third variety (P caribaea var

caribaea, PCC from Cuba) was poor compared to PCH and local pine species It is recommended that future breeding and tree improvement activities should focus on PCH and

PCB for northern Vietnam, and PCH for central and southern Vietnam Development and testing of pine hybrids is likely to be difficult, and so should only form a secondary research priority

1 School of Land and Food Sciences, The University of Queensland, St Lucia Queensland 4072, Australia

2 Research Centre for Forest Tree Improvement, Forest Science Institute of Vietnam, Dong Ngac, Tu Liem, Hanoi

3

Background

Pinus caribaea Morelet, especially P caribaea Morlet var hondurensis (Sénéclauze) W.H

Barrett & Golfari (PCH)has demonstrated fast growth and adaptability to a wide range of sites across the tropics and sub-tropics (Gibson 1982, Birks and Barnes 1990, Dvorak et al

2000) The other two taxonomic varieties of P caribaea (i.e var bahamensis (PCB) and var

caribaea (PCC)) have also shown potential in commercial plantations in some parts of the world with both of these varieties exhibiting greater tolerance to some insect pests (Baylis and Barnes 1989, Kha et al 1989) and greater resistance to wind-damage thanthe Central American (PCH)variety (Birks and Barnes 1990, Dieters and Nikles 2001) Further, PCB has demonstrated greater tolerance to cold temperatures than either PCC or PCH (Nikles 1966 p

103, Duncan et al 1996), which is rather surprising given its natural distribution at low elevation across the Bahama and Caicos Islands.PCH has been used the most extensively for establishment of plantations with large areas planted in Venezuela and Queensland Australia, while significant areas have been planted with PCC in southern regions of China (Dieters & Nikles 1997)

P caribaea was first planted in Vietnam at Da Lat in 1963 (Kha 2003, p.181) with a view to

exploring the potential of this species in commercial plantations as an alternative to native

conifers such as P merkusii and P kesiya The early plantings clearly demonstrated the excellent potential of P caribaea in Vietnam leading to the establishment of a network of

trials from 1976 to the early 1980s in order to provide a more detailed evaluation of the

performance of P caribaea, and to investigate provenance variation Of the Pinus species tested in Vietnam, Pinus caribaea has demonstrated superiority in both adaptability and growth rate, and having better stem form and branching characteristics than P kesiya, P

massoniana or P merkusii (Le Dinh Kha pers comm.) and is regarded as one of the most

promising Pinus species for forest planting in Vietnam (Kha et al 2002) Because of its adaptability, excellent growth and stem form, P caribaea is expected to provide a viable alternative plantation species to Acacia and Eucalyptus on the degraded hills and

low-fertility sites of Vietnam, producing long-fibre pulp for paper manufacture as well as high-quality sawn timber for construction and furniture production A more recent series of trials was established in the early part of this century to investigate impacts of intensive

management on the productivity of P caribaea in an attempt to optimize its performance in

plantations

This report summarizes results from all relevant trials involving P caribaea established

since 1976 across the four major biogeographic regions of Vietnam (northern areas of Vietnam from Hanoi, extending to the border with China; low elevation sites in Central Vietnam; the Central Highlands of Vietnam; and low elevation regions of southern Vietnam

in the vicinity of Ho Chi Minh City) on site-types believed to be suitable for pine plantations (Table 1; Figure 1) Summary data is presented from trials established by the Forestry Research Centre (FRC) 4 at Phu Ninh and the Research Centre for Forest Tree Improvement (RCFTI)5 based in Hanoi

This report aims to: summarize all available (relevant) information on the performance of P

caribaea in Vietnam; make recommendations regarding the potential suitability of P caribaea varieties in each of the major bio-geographic regions of Vietnam; and identify

potential hybrid combinations that may prove successful in Vietnam

4 Trials planted on four sites in the northern region of Vietnam in 1976

5 Forest Science Institute of Vietnam (FSIV) in Hanoi, and partner organizations in other districts of Vietnam

Table 1: Region and location details of P caribaea trials established in Vietnam

(m) Rainfall (mm) Region

South-east (near HCM City) Note: Elevation figures are approximate

Figure 1: Location of trials evaluating the performance of P caribaea in Vietnam

Trials of Caribbean Pine in Vietnam

Summary data (site means) are presented for a total of 17 trials established between 1976

and 2001 (Table 2) Summary data were collated from existing trials of P caribaea, many of

the trials were inspected by project staff from both Queensland and Vietnam, and additional data were collected from: a) some of the older trials that were regarded as still being viable experiments in order to provide later-rotation data for this review; and, b) relevant species/provenance/management trials established since 2000 (Table 2)

For consistency with previous analyses, all data collected in 2006 were analysed on a plot mean basis, and tree volumes were estimated using the following formulae:

f ht

dbh

⎠

⎞

⎜

⎝

⎛

=

2 2

Where diameter at breast height (dbh) and total tree height (ht) are both in decimetres, and a form factor (f) was taken to be 0.5 Based on experience in Queensland, it is likely that use

of this generic volume equation will over-estimate the true volume Consequently, volume data presented should be treated with caution However, as all previous analyses had used this form factor, 0.5 was retained to allow comparisons amongst trials Individual tree volumes were summed within each plot, and divided by plot area and age to estimate mean annual increments expressed in m3 ha-1 yr-1

The older trials (i.e those established before 1985) typically included other pine species such

as P kesiya, P merkusii and P massoniana for comparison (Table 2) At that time these species had been used the most extensively for plantation establishment in Vietnam – P

massoniana in northern Vietnam, and P kesiya and P merkusii in central and southern

Vietnam Results of these species comparisons have been previously reported by a number

of authors (e.g Ståhl 1988, Dien 1989 and Kha 2003, p 182) and the universal conclusion

was that P caribaea is faster growing than alternative Pinus species across a range of sites

in Vietnam For example, Dien (1989, p 64) concludes that “Pinus caribaea grew faster than

other species on all sites” Consequently, data on the performance of other species in the early trials (1976) planted by FRC have not been included here – full details on the performance of all species in these trials are presented in Ståhl’s (1988) comprehensive

report This report will focus on the relative performance of the three varieties of P caribaea

and provenance variation within this species

Table 2: Listing of all trials used to review the performance of P caribaea in Vietnam

Last Measure

No Region Location Trial Type Species/Taxa

Year Planted

No

Entries

Trees per Plot

No

Reps

Spacing (r×t, m) Date Age (yrs)

1 North Den Hung - Phu Tho Species/Provenance trial

P CH , P MERK , P OOC ,

2 North Son Nam-Tuyen Quang Species/Provenance trial P

CH , P MERK , P OOC ,

3 North Thai Long- Tuyen Quang Species/Provenance trial

P CH , P MERK , P OOC ,

4 North Yen Kien - Phu Tho Species/Provenance trial P

CH , P MERK , P OOC ,

5 Central Dong Ha - Quang Tri Species/Provenance trial P MERK , P CC , P EE 1980 5 4 Mar-00 19.3

6 North Dai Lai - Vinh Phuc Species/Provenance trial P

CH , P CC , P MASS ,

P MERK , P OOC , P EE 1981 12 49 4 3×2 Mar-00 19.1

7 North Dai Lai - Vinh Phuc Species/Provenance trial P CH , P CC , P OOC , P EE 1982 9 36 4 3×2 Jan-00 17.8

8 Central Dong Ha - Quang Tri Species trial P CH , P MERK 1984 2 1 Mar-00 15.7

9 South-East Song May - Dong Nai Provenance trial P CH 1987 7 49 7 3×2 Apr-06 18.8

10 North Dai Lai - Vinh Phuc Provenance trial P CH 1987 7 36 5 3×2 Jan-00 12.4

11 Central Dong Ha - Quang Tri Provenance trial P CH 1988 6 3 Mar-00 11.4

12 Central Highlands Pleiku - Gia Lai Provenance trial P CH , P CB , P CC 1990 11 49 4 3×2 May-06 16

13 North Xuan Khanh - Ha Tay Provenance trial P CH , P CB , P CC 1990 10 49 3 3×2 Mar-00 9.5

14 Central Highlands Lang Hanh - Lam Dong Provenance trial P CH , P CC 1991 7 25 4 3×2 Mar-00 8.7

15 North Cam Quy - Ha Tay Taxa comparison trial P

CB , P CC , P CH , P EE ,

P EE × P CH F 2 1996 5 36 4 3×3 Sept-06 10.4

16 North Cam Quy - Ha Tay Intensive management P CB , P CH × fertilizer 2000 3 15 4 3×3 Apr-06 5.8

17 Central Highlands Lang Hanh – Lam Dong Species/Provenance trial P CC , P CH , P EE 2001 6 30 4 3×2 May-06 4.8

18

Central

Highlands Lang Hanh, - Lam Dong) Intensive management P CC , P CH × fertilizer 2001 3 30 3 3×2 May-06 4.8

Species/Taxa: P CB = P caribaea var bahamensis, PCC =P caribaea var caribaea, PCH = P caribaea var hondurensis, PEE =P elliottii, PKES = P kesiya, PMASS =

P massoniana, PMERK = P merkusii, POOC =P oocarpa

Growth and Survival

The results presented here are a compilation of summary data from trials established over a

25 year period across the length of Vietnam, established for a range of purposes The earlier

trials aimed to evaluate the performance of P caribaea in comparison to the local pine species (P kesiya, P merkusii, and P massoniana) The focus of the trials then moved to evaluation of provenance variation within P caribaea, and finally investigation of the growth potential of P caribaea through fertilizer application Due to the long period over

which the trials were established, the results are potentially confounded by the low survival (often less than 50%) in many trials that resulted from a combination of effects including: illegal harvesting, fire damage, and possibly inadequate establishment silviculture The differential stocking levels both within and between trials are likely to bias evaluations of diameter and volume production of the taxa at later ages, consequently height data may be the most reliable trait for taxa comparisons Further, no reliable volume equations are

available to compare volume differences between species, or between varieties of P

caribaea in Vietnam, therefore differences in stem taper and bark thickness will alter

rankings of species and taxa In the absence of a reliable volume equation for P caribaea in

Vietnam, productivity estimates should only be regarded as approximate

Forest Research Centre (FRC, Phu Ninh) Trials Established 1976:

Four trials were established by FRC in 1976 in northern Vietnam (Table 2, Trials 1 – 4) to assess species differences and provenance variation within species The trials included all

three varieties of P caribaea (4 provenances of PCH,and 1 each of both PCB and PCC,Table 3; however, a fifth provenance of PCH (Alimicamba) was also included at one site but no data are presented for this provenance) The trial planted at Thai Long was damaged by fire

in 1977 when the trial was less than 2 years of age, resulting in significant mortality, therefore no results are presented for this site Summary data are presented for the three remaining sites at 8 years of age (Table 4), and the Son Nam site at 25 years of age (Table 5)

Table 3: Provenances of P caribaea tested in Forest Research Centre trials

202 Poptún, Penten, Guatemala

203 Guanaja Island, Honduras (var

hondurensis)

16°27' N 85°54' W 75

204 Andros Island, Bahamas

205 Cajalbana, Cuba

(var caribaea)

20°30' N 81°31' W 150

206 Mountain Pine Ridge, Belize

(var hondurensis)

17°00' N 88°55' W 400

207 Poptún, Penten, Guatemala

The results indicate that as a species, P caribaea is capable of reasonable growth rates in the

northern region of Vietnam, with the best provenance (Mountain Pine Ridge, 206) averaging nearly 20m in height at 25 years of age on the Son Nam site Results observed here indicate relatively little variation in growth rates between the provenances of PCH, but PCC (205) grew rather slowly compared to either PCB or PCH, and does not appear suited to sites in northern Vietnam By contrast PCB had the fastest height growth to 8 years of age (Table 4) and was second only to the Mountain Pine Ridge provenance of PCH at 25 years of age

(Table 5) Of the PCH provenances tested, the upland sources from Poptún and Mountain Pine Ridge appear to be better than the Guanaja source

Table 4: Mean height and tree volume of P caribaea at 8 years (1984) of age in FRC trials

(Trials 1 – 4, refer Table 2)

Code Height (m) (dmVolume 3 /tree) Height (m)

Volume (dm 3 /tree) Height (m)

Volume (dm 3 /tree)

202 6.1 66 8.6 207 8.9 201

203 5.4 56 8.2 188 9.1 164

204 6.9 65 9.4 184 9.6 213

205 6.5 65 6.4 112 9.0 173

206 5.9 56 8.7 216 9.2 200

207 6.1 68 8.5 206 9.0 193 LSD — — 1.16 47.6 0.75 41.7

Note: Entry 204 = P CB , 205 = P CC , all other entries are P CH

Table 5: Mean growth and survival of P caribaea at 25 years of age (2002)

at Son Nam site in FRC trials (Trial 2, refer Table 2)

Code Diameter (cm) Height (m) (dmVolume 3 /tree) Volume (m 3 /ha) Survival (tree/ha)

Note: Entry 204 = P CB , 205 = P CC , all other entries are P CH

In Ståhl’s (1988) report, he highlights a further complication that is not reflected in the data presented above – “a large difference in the form and tapering between mainly the Bahamas

and the var hondurensis provenances The Cuban variety is intermediate.” Generally PCB is much straighter with less taper than PCH both in these trials (as reported by Ståhl, 1988), in Queensland and in other parts of the world It is also likely that PCB has thinner bark than

PCH When taken together (better stem form, less taper and thinner bark) it is likely that PCB

may produce greater utilizable volume than PCH when grown in the northern region of Vietnam Further, the known superior insect and frost tolerance of PCB may also provide additional benefits over PCH on some sites in the northern region of Vietnam

Species and Provenance within Species Trials Established 1980 – 1984:

In the early 1980s four species trials and provenance within species trials were established

by RCFTI and its partners – two trials in northern Vietnam at Dai Lai and two in central

Vietnam at Dong Ha (Table 2, Trials 5 – 8)

In the two trials established at Dong Ha in central Vietnam, even though the first trial was

unreplicated, P elliottii growth rates were approximately half that of P merkusii (Table 6) at

19 years of age In central Vietnam P elliottii is well south of its natural latitudinal range,

and appears to be poorly adapted to sites in central Vietnam This unreplicated trial at Dong

Ha only includes the slower growing Cuban variety (PCC) of P caribaea, which did not

perform as well as the best provenances of P merkusii on this site In the second trial at

Dong Ha (Table 7) only PCH and P merkusii are included, with PCH showing greater height

and volume than P merkusii but smaller diameter to 15 years of age A similar trend was

also observed in the earlier unreplicated trial (Table 6) where PCC was taller than the best

provenance of P merkusii but with reduced diameter

Table 6: Mean growth at 19 years of age, in species/provenance trial established at Dong Ha

in 1980 (Trial 5, refer Table 2)

Species Provenance/Source Diameter (cm) Height (m) Volume/tree (dm 3 )

Note: This trial only contained a single replicate of each species/provenance

In the first of the two trials established at Dai Lai in northern Vietnam, the Honduras

provenance of PCH was clearly superior in height to all other species; however, overall

survival is poor (Table 8) P massonianna was generally second to PCH, followed by P

oocarpa6 and PCC Here P elliottii performs better than at Dong Ha (Table 6), but is still

clearly inferior to PCH, PCC and P massoniana The native conifer (P merkusii) did not

perform well in comparison to P caribaea or P massoniana at Dai Lai, with substantially

less height growth (Table 8)

The final trial of this set of four experiments does not include any of the local pine species –

only species from the Americas (Table 9) Again the Honduras source of PCH is superior in

height growth to the other provenances of PCH, and PCH is similar to P oocarpa in growth

rates, but clearly superior to both PCC and P elliottii

These results suggest that PCH is likely to be superior in both height and diameter growth to

both P merkusii and P massoniana in northern Vietnam, and superior in height growth to P

merkusii in central Vietnam PCC was inferior in growth rates to the local pine species and

PCH on sites in both central and northern Vietnam P elliottii was poorly adapted to sites in

central Vietnam

6 Possibly P tecunumanii – P tecunumanii was not separated taxonomically from P oocarpa until after this

trial was established

Table 7: Mean growth at 15.6 years of age, in species trial established at Dong Ha in 1984

(Trial 8, refer Table 2)

Species

Diameter (cm)

Height (m)

Volume/tree (dm 3 )

Table 8: Mean growth and survival at 19 years of age, in species/provenance trial established

at Dai Lai in 1981 (Trial 6, refer Table 2)

Species Source/Origin Diameter (cm) Height (m) Volume/tree (dm 3 ) Survival (%)

P massoniana

Yen Lap -

P massoniana

Loc Binh -

P merkusii

Ha Trung –

Note: Results previously reported by Kha (2003, Table 7.6, p 182)

Table 9: Mean growth and survival at 17.8 years of age, in species/provenance trial

established at Dai Lai in 1982 (Trial 7, refer Table 2)

Species Provenance/Source

Diameter (cm)

Height (m)

Volume/tree (dm 3 )

Survival (%)

Provenance Trials of P caribaea Established Between 1987 and 1991:

In the five year period from 1987 to 1991 RCFTI and its partners established six provenance

trials of P caribaea: two in northern, one in central, one in south and two in the Central

Highlands region of Vietnam (Trials 9 – 14, Table 2) These trials differ from the earlier trials by not testing any local pine species and including Queensland (Australia) and local

sources of P caribaea as well as sources from the species natural range

Results from these trials between 8.7 and 18.8 years of age (Tables 10 – 15, Figures 2 and 3) indicate that there was relatively little variation between provenances of PCH There is certainly no pattern to the observed growth performance of provenances in these trials – low-elevation sources such as Alamicamba and Guanaja do not appear to perform consistently better or worse that higher-elevation sources such and Poptun or Mountain Pine Ridge (MPR) Nor does provenance origin appear to reflect adaptation to site types in Vietnam (particularly low-elevation versus high elevation) with low-elevation sources of PCH

performing well on high-elevation sites in the Central Highlands, and higher-elevation sources performing well on low-elevation sites in northern and central regions of Vietnam

Two of the trials (Tables 11 and 13) include all three varieties of P caribaea Relative

performance of these varieties differed in these two trials – the first in northern Vietnam at

Ha Tay, and the second in the Central Highlands at Pleiku In northern Vietnam the mean diameter of PCB was similar to that of PCH but the best PCB provenances had much greater height than the best PCH provenances (Table 11) However, PCC performed poorly compared

to both PCB and PCH on this site in northern Vietnam In contrast, in the trial located at Pleiku in the Central Highlands, PCC was the fastest growing of all varieties tested (Table 13) with the largest mean diameter, while PCB generally had the smallest mean diameter and volume This difference between the Ha Tay and Pleiku sites may reflect the differences in age between the trials and differences in the growth curves of these varieties, or differences

in stocking Alternatively, the observed differences may reflect true differences in the

adaptation of P caribaea varieties to sites in Vietnam – suggesting that the bahamensis variety is better adapted to northern regions, while the caribaea variety from Cuba is better adapted to the Central Highlands By contrast the hondurensis variety appeared to show

much greater adaptability than either PCB or PCC, growing well across a wide latitudinal range in Vietnam

The improved sources of P caribaea imported from Queensland that were included in these

trials have performed equal to or better than the natural sources ofPCH tested (Figures 2 and 3) The Queensland seedlots tested are probably derived from first generation clonal seed orchards, largely composed of trees selected in the Mountain Pine Ridge (MPR) provenance from Belize In the first cycle of genetic improvement in Queensland most emphasis was

placed on improving the stem form of P caribaea, and comparatively small gains were

made in growth rates (Nikles 1996) The results presented in these tables and graphs do not reflect improvements in stem form, which were clearly evident when the trials at Pleiku and Song May were remeasured for this report in early 2006 Nevertheless, it is clear that material selected in Queensland, can and does perform well when planted across all site-types in (northern, central, central highlands and southern) Vietnam

The general performance of the three varieties of P caribaea observed in these trials is

entirely consistent with results reported for international provenance trials, where PCH

demonstrated much faster growth rates across a wide range of sites than either PCB or PCC, but PCH had inferior stem straightness and generally less resistance to wind-damage (Birks

and Barnes 1990) However, the relatively small amount of provenance variation in P