Problems in Restoring Native Trees to Barren Tropical Pasture

Problems in restoring native trees to barren tropical pasture

Lynn Carpenter, Doland Nichols, Eduver Sandi, and Grad students: Mary Anderson, Riley Pratt, Calen May- Tobin, Kristin Young

Undergraduate students: Laura Antonie and Sotheary Son

1 Goals and approaches of our project in 1992 • Overall: Use native trees to reclaim extremely degraded pastureland – Reason: to provide future information when more farms reach that state

– Goal 1: jump-start forest succession – Goal 2: restore economic value to farm

• Our approach was two-fold – Basic science: • Test ecological concepts such as successional facilitation – Applied science: • Develop practical methods with minimal capital outlay for local farmers

2 Our 6-wk search for the perfect study site • Criteria: – Lack of topsoil as judged by color

– Depth of cattle trails—to 2m

– Extent of bare land— 50%

• Site: southwestern Costa Rica – Comparable to other projects?

3 Finca Cantarana

• 25 ha @ 1020m, 4400mm/yr rainfall • History: – Mid-1950’s: cleared for coffee – Mid-1970’s: converted to pasture, overgrazed • 1992: research began

4 Initial soil characteristics

5 Soil fertility and classification

• Infertile compared to Finca Cantarana Las Alturas 18.00 other pasture sites in 16.00 CR 14.00 12.00 – Las Alturas (Holl 1999) & 10.00 Finca Cantarana (Nichols et 8.00 al. 2001) 6.00 • Ultisol with andic 4.00 2.00 Relevant units [(cmol(+)/L) or (%)] [(cmol(+)/L) units Relevant influences 0.00 pH Ca Mg K CEC Tot N OM – CIA – Five 2-m soil profiles

6 Initial soil chemistry in 1993 Means @ 0-15cm (n=45) pH Ca Mg K Acidity AL CICE P PO4

(cmol(+)/L) % sat. (cmol(+)/L) (mg/Kg) (ug/g)

5.0 5.3 1.4 0.13 3.3 33.5 10.2 1.6 0.64

OM N NH4 NO3 Cu Fe Mn Zn % % (ug/g) (ug/g) (mg/Kg) 5.4 0.28 7.2 54.7 12.8 435.3 145.6 1.25

B93 Experiment on Finca Cantarana. Depth 0-15cm. Analyses done by CIA: pH in water; bases in ammonium acetate; P Olsen, PO4 resin membrane

7 First step: What tree species can grow? “Ensayos” 1994, 1996, 1998 (species assayed are in blue on next slide)

8 List of species planted (Arboles de Costa Rica vols. I-III) Non-natives (3) Other natives (cont.) • Eucalyptus deglupta (Myrtaceae) • Annona muricata (Annonaceae) • Pinus tecunumanii (Pinaceae) • Aspidosperma spruceanum • Inga edulis (Fabaceae) (Apocynaceae)? ‘amargo’ Native legumes (10) • Astronium graveolens (Anacardiaceae) • I. spectabilis (Fabaceae) • Calophyllum brasiliense (Clusiaceae) • Albizia carbonaria (Fabaceae) • Carapa guianensis (Meliaceae) • Calliandra calothyrsus (Fabaceae) Cecropia obtusifolia (Cecropiaceae) • Diphysa robinioides (Fabaceae) • Cedrela odorata (Meliaceae) • Gliricidia sepium (Fabaceae) • C. tonduzii (Meliaceae) • Lonchocarpus sp. (Fabaceae) • Ceiba pentandra (Bombacaceae) ‘chaperno’ • Hyeronima oblonga (Euphorbiaceae) • Platymiscium pinnatum (Fabaceae) • Juglans olanchana (Juglandaceae) • Schizolobium parahyba • Minquartia guianensis (Olacaceae) (Caesalpinaceae) • Tabebuia chrysantha (Bignoniaceae) • Samanea saman (Fabaceae) • Tabebuia rosea (Bignoniaceae) ‘cenizaro’ • Terminalia amazonia (Combretaceae) • Zygia longifolia (Fabaceae) ‘soto caballo’ • Vochysia guatemalensis (Vochysiaceae) Other natives (19) • V. ferruginea (Vochysiaceae) • Anacardium excelsum (Anacardiaceae) ‘espavel’ • 2 species of unidentified Lauraceae (”bambito”, “aguacatillo”)

9 Ensayo Results: Mortality

• Seedling and sapling mortality is high.

“hueco de infierno” #2

10 Ensayo 1994 Mortality over 7yr (n small for calculating growth) Initial n = 87 of each species 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 Proportion dead 0

) is ia ta s s nus lum ra u i nal yl o P d mi ph o malen er o T al ucalypt ate E u C ( g Cedrela V.

(Tabebuia chrysantha)

11 Ensayo 1996 Mortality over 9.5 yr ( ) small n for calculating growth

Initial n = 90 of each species, except Annona, Astronium, “bambito”, Platymiscium (n= 21-63) 1.00 0.80 0.60 0.40 0.20 0.00 Proportion dead Proportion m i) ) ilis lis m u zi b u iu ci na) a d inalia s o ct e m ndu I. tron o er ospermatymi (Ann t (bambito ferruginea As T d la I. spe e V, Pla r Aspi d (Ce

12 Ensayo 1998 Mortality over 11 yr ( ) small for calculating growth 1 0.9Initial n = 90 for each species, except Calliandra and Gliricidia (n=45) 0.8 0.7 0.6 0.5 0.4 0.3

Proportion dead 0.2 0.1 0 ia a a ) ma lis l s ia ia) i u a y id iz ed ic lb r A scium) I. Diph ( mi Hyeron Termin Calliandr (Gli Schizolobium (Platy

13 Ensayo results: Growth

Slow compared to the minimum values found in the literature

14 Ensayo 1994

Growth comparisons with other sites FC species @ 14yr Data for FC spp in ( ) are doubtful because of small n’s

600 ) 500 FC Other 400 300 200 100 Growth (cm/yr Growth 0 Pinus odorata Cedrela V. (Tabebuia chrysantha) Calophyllum (Eucalyptus) Terminalia93 guatemalensis

15 Ensayo 1996

Growth comparisons with other sites (FC spp @ 9.5 yr) Data for FC spp in ( ) are doubtful because of small n’s 350 FC LIT 300 250 200 150 100

Growth (cm/yr) Growth 50 0 ) lis tabilis iscium uginea nduzii I. edu osperma m Terminalia a to d (Annona) Astronium , ferr el laty V I. spec spi P edr A (C

16 Ensayo 1998

Growth comparisons with other sites FC spp @ 4yr

FC Other 500 450 400 350 300 250 200 150

Growth (cm/yr) 100 50 0

is ia zia um bi andra inalia ci Al i m liricid is I. edul Diphysa G Call Hyeronima Ter ym lat Schizolobium P

17 Mortality may worsen over time or nullify growth

Note Schizolobium († ), Albizia (!) Ensayo 1998 Mortality over 4 yr 0.90 0.80 (FC E98 @ 4yr growth) 0.70 ! 0.60 0.50 120 0.40 ! 0.30

Proportion dead Proportion 0.20 † 100 0.10 80 0.00 ra a m d lia i u ulis ima n a d in lbiz icidia 60 iphysa llia A r I. e eron D y a Gli H C Term 40 Schizolobi Platymiscium Growth (cm/yr) 20 Ensayo 1998 Mortality over 11 yr ( ) small for calculating growth 0 1 † a a r lis lia s ima u 0.9 nd n ed Albizia llia . 0.8 I Diphy Gliricidia 0.7 Ca Hyero Termina ymiscium at 0.6 Schizolobium Pl 0.5 0.4 0.3

Proportion dead Proportion 0.2 0.1 0

lis a ali ima n ium i icidia) on m iphysa liandra lob r lbizia) cium) I. edu r D i (A s zo Hyer Te Cal (Gl chi S (Platymi

18 So, few natives establish and grow. Worse, terrain has been a factor Ridges > slopes > valleys

19 Soil characteristics of different terrains

First, compare ridges and slopes. Then, slopes and valleys…

20 Soil on ridges and slopes

Soil chemistry Ridges vs. slopes (Young and May-Tobin 2008) 12.00 ** 10.00 * 8.00

Ridge 6.00 ** ** Slope 4.00 * * cmol(+)/L mg/L mg/kg mg/L cmol(+)/L 2.00 ** 0.00 ** pH Ca Mg K CEC Cu P NO3- Measure

21 This student lost most trees in his four ridge blocks • (half the experiment). • No more grad student projects on ridges!

22 Soil on slopes and valleys (R. Pratt 2009)

Also, AMF differed: Acaulospora on slopes, not valleys

23 Mortality and growth on different terrains

Terminalia amazonia

24 Ensayo98: Mortality by location on slope

Bottom Next Up Nr ridge Ridge Top ridge

1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20

Proportion of mortality Proportion of 0.10 0.00

a ia m id ima um u hysa n Inga i bi inalia liandra p ric sc o Albizi l rm Di Gli yero zol e Ca H T Platymi Schi • Tended to increase uphill: Hyeronima showed no pattern, and its mortality was lowest

25 Ensayo 98: Growth by location on slope

16 Bottom Next up Near ridge Ridge Top

14 (species in () have small n’s) 12

10 8

Mean dbh (cm) Mean 4

0 ) ) ) a ) ia ia) m iz ys d iu lb iandra onima iscium r I. edulis (A Diph zolob (Glirici Hye i (Call latym ch (Terminalia) (P (S

• Hyeronima and Inga tended to decrease growth uphill. • Some other legumes show the trend but n’s are small.

26 Soil moisture may be a factor

• Two experiments over the dry season

27 Calophyllum brasiliense

Growth (sig. different @ p<.001) Soil moisture (sig. different @ p<.001)

Flats on black plastic Flats on black plastic

28 Inga spectabilis

Growth (sig. different @ p<.001) Soil moisture (sig. different @ p<.001)

Flats on black plastic Flats on black plastic

29 At this point, I’ll sum a few lessons we have learned …

30 Experimental design

• Super-degraded sites • For example: require special – Ensayos had few trees per treatment per block (3) but

consideration a good # of blocks (30) • Block the experiment – B93 had too few blocks (5) and too many trees per

by terrain treatment per block (93) • Expect high mortality, so balance # blocks (reps) and # trees per treatment within blocks

31 Best species for Finca Cantarana (of 23)

• Pinus tecunumanii • But their performance may worsen over longer time periods • Vochysia • All except pine grow guatemalensis comparatively slowly • V. ferruginea • None except pine can grow on • Hyeronima oblonga high ridges or in hellholes. • Inga spectabilis • I. edulis

32 One last question: Can these best species help others grow?

Facilitation

33 The search for facilitator species

• Inga spp (N-fixing legume, Fabaceae) – I. edulis increased N and growth in Terminalia (sig. @ p<.001) – No other legume genus so far has potential as facilitators

• Vochysia spp – A priori arguments about P availability – Leaf mulch of V. guatemalensis increased growth in Astronium and Tabebuia (sig. @ p<.0001) – Other experiments with seedling Vochysia n.s.: may need more time to grow • Pinus tecunumanii – We can allay fears about mycorrhiza—pines did not inhibit AMF colonization (p>.28) – Preliminary data (n.s.) suggest that 12yr old pines may facilitate….

34 Mean growth under V. guatemalensis and Important to test P. tecunumanii @ 3.5yr for economic reasons: 20.0 Control On FC, 1 ha @ 15.0 10.0 Vochysia 15yr ≥ $90,000 5.0 Pinus (1 tree=$90) 0.0 Growth (cm/yr) Growth ia m u iu b yllum c ium) e h s n b p o a o tr T l tym i s a A C Pla (

35 In conclusion: returning to our 1992 goals • Can we restore economic value to these lands? – Pine may be the only option for the farmer when land is this bad

• Can we jump-start natural succession? – Slopes and valleys are feasible – Establishing cover begins the process.

– Legumes may facilitate. • Main conclusion: the sooner the intervention, the better

A valley plot @ 12 years 36 Thanks to:

• UCI, RAIN, Earthwatch, UREP, CIA, OTS for financial and logistical support. • Incredible ticos for field and lab assistance as well as discussions of scientific and cultural import: – Leonel Figueroa, Rolando Mendez, Diego Sandi, Yolanda Rojas, Ana Herra, Gloria Melendez, Carlos Henriquez, Luis Diego Gomez, and many others. • Nancy Adrian and Martha Rosemeyer for their understanding • And “Manchita” and “Newton” for moral support

37 List of species planted (Arboles de Costa Rica vols. I-III) Non-natives (3) Other natives (cont.) • Eucalyptus deglupta (Myrtaceae) • Annona muricata (Annonaceae) • Pinus tecunumanii (Pinaceae) • Aspidosperma spruceanum • Inga edulis (Fabaceae) (Apocynaceae)? ‘amargo’ Native legumes (10) • Astronium graveolens (Anacardiaceae) • I. spectabilis (Fabaceae) • Calophyllum brasiliense (Clusiaceae) • Albizia carbonaria (Fabaceae) • Carapa guianensis (Meliaceae) • Calliandra calothyrsus (Fabaceae) Cecropia obtusifolia (Cecropiaceae) • Diphysa robinioides (Fabaceae) • Cedrela odorata (Meliaceae) • Gliricidia sepium (Fabaceae) • C. tonduzii (Meliaceae) • Lonchocarpus sp. (Fabaceae) • Ceiba pentandra (Bombacaceae) ‘chaperno’ • Hyeronima oblonga (Euphorbiaceae) • Platymiscium pinnatum (Fabaceae) • Juglans olanchana (Juglandaceae) • Schizolobium parahyba • Minquartia guianensis (Olacaceae) (Caesalpinaceae) • Tabebuia chrysantha (Bignoniaceae) • Samanea saman (Fabaceae) • T. rosea (Bignoniaceae) ‘cenizaro’ • Terminalia amazonia (Combretaceae) • Zygia longifolia (Fabaceae) ‘soto caballo’ • Vochysia guatemalensis (Vochysiaceae) Other natives (19) • V. ferruginea (Vochysiaceae) • Anacardium excelsum (Anacardiaceae) ‘espavel’ • 2 species of unidentified Lauraceae (”bambito”, “acuacatillo”)