Impact of logging intensity on stem density, basal area and biodiversity indices five years after logging in a Caspian hardwood forest

Transcription

1 JOURNAL OF FOREST SCIENCE, 63, 2017 (4): doi: /103/2016-JFS Impct of logging intensity on stem density, sl re nd iodiversity indices five yers fter logging in Cspin hrdwood forest Frshd KEIVAN BEHJOU*, Omid GHAFFARZADEH MOLLABASHI Deprtment of Rnge nd Wtershed Mngement, Fculty of Agriculture nd Nturl Resources, University of Mohghegh Ardili, Ardil, Irn *Corresponding uthor: Astrct Keivn Behjou F., Ghffrzdeh Mollshi O. (2017): Impct of logging intensity on stem density, sl re nd iodiversity indices five yers fter logging in Cspin hrdwood forest. J. For. Sci., 63: The im of the present study ws to nlyse the impcts of different logging intensities fter five yers from logging including non-logged, low (3.4 felled stems per hectre), medium (5.2 felled stems per hectre) nd high (7.1 felled stems per hectre) tretments on stem density, sl re, cnopy cover, nd forest iodiversity indices. The study re ws locted in northern Irn. Dt ws collected on set of 120 circulr plots with 5 m rdius from oth non-logged nd logging res. Stem density, sl re, nd percentge of cnopy cover were mesured. Biodiversity study ws done y mesuring two diversity indices including Simpson s nd Shnnon-Wiener s, two richness indices including Mrglef s nd Menhinick s nd two evenness indices including Pielou s nd Hill s indices. The results indicted tht the tretment with the medium logging intensity ws found to cuse the highest mount of positive effects on stem density, sl re, nd iodiversity indices. It is concluded tht hrvesting intensity should e limited to medium level (pproximtely 5 felled trees per hectre) during ech logging opertion to improve forest iodiversity indices. Keywords: hrvesting intensity; forest iodiversity; northern Irn Cspin forests re importnt for environmentl resons such s iodiversity, protection of plnts nd nimls nd s cron sink (Erikson et l. 2012). These forests elong to the rich nd iologiclly diverse ecosystems in Irn with vlule vriety of endemic species. It is proved tht the ecosystems with high species diversity re more stle nd resilient to humn disturnces compred with those hving low species diversity (Hegetschweiler et l. 2009; Tynsong, Tiwri 2010). Biologicl diversity is now recognized incresingly s vitl prmeter to ssess glol nd locl environmentl chnges nd sustinility of developmentl ctivities (Sh et l. 2011). Selective logging hs een denoted s the prctice of hrvesting the most importnt timer species in nturl forests, llowing the remining forest to nturlly regenerte over time (Bw, Seidler 1998). Selective logging, the hrvest of vlule timer trees ove threshold stem dimeter with prescriptions designed to mintin the forest cover, is considered to e etter prctice compred with cler-cutting nd it is incresingly emrced s n pproch to protect forest integrity while llowing n pproprite use of resources (Deckker, De Grf 2003; Rmetsteiner, Simul 2003). In recent decdes, mny tropicl forest ntions hve dopted the mechnized selective logging regimes for timer production (Gscon et l. 1998; De Wsseige, Defourny 2004; Drigo et l. 2009). Biodiversity mintennce is key mngement ojective nd requisite for sustinle forestry nd it is necessry J. FOR. SCI., 63, 2017 (4):

2 to understnd the dynmics nd heterogeneity of nturl forests to provide guidelines for mngement (Spies, Turner 1999; Lindenmyer et l. 2000). Despite the wek scientific evidences, selective logging is considered s sustinle forest mngement prctice nd it is incresingly emrced s n pproch to protect forest integrity while llowing n pproprite use of resources. Undistured tropicl forests hve ecome extremely rre (Grdner et l. 2009). Thus, forest mngement should focus on mximizing the conservtion vlues of humn-modified forest (Grdner et l. 2009). In this context, selective logging ws proposed s mngement option to mintin conservtion vlues, in terms of cron stocks nd iodiversity, s well s the economic vlue of once-logged forest (Putz et l. 2012). In this context, forest logging ctivity cn e understood s disturnces tht my hve lrge influence on the iodiversity of the forest. Logging ctivities cn cuse extensive dmge to soil, ground vegettion, shrus nd trees (Behjou, Mollshi 2013). In recent yers, reserch on iodiversity in mnged lndscpes hs een motivted y species declines nd hitt loss (Hlpern, Spies 1995) nd the use of mngement prctices to emulte nturl disturnces nd dynmics hs een explored in severl studies (Hnsen et l. 1991; Niemel 1999). The comptiility of logging ctivities nd iodiversity conservtion in forests is criticl chllenge (Behjou, Mollshi 2013), not only ecuse of societl demnds ut lso ecuse humn-mnged ecosystems re criticl for mintining iodiversity (Pimentel et l. 1992). Our study ims to ssess the effects of logging intensity on some forest site prmeters nd forest iodiversity indices in the Cspin forest. Specificlly, the im of this study is to nlyse the effects of logging intensity on iodiversity indictors of tree species diversity, richness nd evenness. Little informtion is ville out the impct of logging intensity on some forest site prmeters nd iodiversity indices. The Cspin forests in the north of Irn, s n importnt ecologicl re, re considered to elong to the res of Irn with the richest iodiversity. The impct of forest logging on popultion chrcteristics is well documented ut little is known out the impct on iodiversity, so the min ojectives of the present study re: (i) compring indictors of iodiversity etween non-logged nd logged res, (ii) evluting the effects of different logging intensities on stem density, sl re nd iodiversity indices. MATERIAL AND METHODS Mteril. The study ws performed in the Hyrcnin forest region of Irn (north of Irn). Conditions in the region hve fvoured gret vegettion diversity nd numer of endemic species. In the region, some prts of the forest hve een impcted y logging ctivities for decdes nd smll mount of non-logged forests remins. The dominnt forest tree species in the region re hornem (Crpinus etulus Linneus), eech (Fgus orientlis Linneus) nd mple (Acer velutinum Boissier). The study ws done 5 yers fter logging. Methods. Smpling plots re locted ccording to systemtic smpling design in the intersections of the m grid tht fll inside forests, with n verge smpling intensity of four plots per hectre of lnd. Plots were circulr nd concentric, with fixed size, with plot rdius of 5 m (pproximtely 78.5 m 2 ). The totl numer of smpling plots tht were nlysed ws 120 in the logged forest. Generlly, in studied prts 2 res including impcted res (3 different logging intensities) nd one nonlogged re were studied y smpling. Sixty plots re locted in control re (non-logged re) nd sixty re locted in logging res (impcted re) (totlly 120 plots). The logging re ws divided into three ctegories including low intensity (20 plots), medium intensity (20 plots), nd high intensity (20 plots). Biodiversity study ws done y mesuring two diversity indices including Simpson s nd Shnnon-Wiener diversity index, two richness indices including Mrglef s nd Menhinick s diversity index nd two evenness indices including Pielou s nd Hill s diversity index. ANOVA ws used to exmine the impct of different logging intensities on the numer of individul trees, sl re nd the mount of cnopy cover. To test for significnt effects of different logging intensities (low, medium, nd high), the men vlues for the iodiversity indictors on the plots were contrsted with those corresponding to the control plots. RESULTS AND DISCUSSION Descriptive sttistics for the numer of individuls per hectre, sl re per hectre nd cnopy cover per hectre re given for ech re in Tle 1. Summry sttistics re given for estimtes of ech vrile nd for ech re (protected nd logged res with different logging intensities) (Tle 1). The 168 J. FOR. SCI., 63, 2017 (4):

3 Tle 1. Descriptive sttistics of the vriles in the plots in four tretments* Vrile Tretment Numer Men SD non-logged Stem density (No. of stems per h) low logged* medium high non-logged Bsl re (m 2 h 1 ) low logged* medium high non-logged Cnopy cover (%) low logged* medium high *including non-logged, low, medium nd high logging intensity; SD stndrd devition Tle 2. The diversity indices of control nd distured res Index Tretment logging intensity diversity richness evenness Simpson Shnnon-Wiener Mrglef Menhinick Pielou Hill Non-logged 0.53 (0.02) 0.88 (0.06) 0.81 (0.04) 0.85 (0.07) 0.83 (0.04) 0.83 (0.02) low 0.66 (0.08) 1.22 (0.15) 1.29 (0.12) 0.91 (0.06) 0.88 (0.03) 0.86 (0.09) Logged medium 0.68 (0.05) 1.26 (0.09) 1.30 (0.10) 0.90 (0.08) 0.91 (0.11) 0.89 (0.05) high 0.61 (0.03) 0.90 (0.05) 0.87 (0.15) 0.82 (0.03) 0.85 (0.04) 0.81 (0.01) the vlues of stndrd errors re shown in prentheses results of one-wy ANOVA indicte tht logged stnds hd significntly lower stem density (F 3, 119 = 45.43, P = 0.000), sl re (F 3, 119 = 31.36, P = 0.000), cnopy cover (F 3, 119 = , P = 0.000), diversity (F 3, 119 = , P = 0.000), richness (F 3, 119 = , P = 0.000), nd evenness (F 3, 119 = , P = 0.000) thn non-logged res (Tles 2 nd 3). The results of Duncn s test indicte tht the stem density in high logging intensity ws significntly smller thn in the other three tretments (Fig. 1). The lower stem density in the non-logged re indicted tht logging ctivities tended to increse density with the incresing intensity of logging. In the non-logged re sl re ws significntly higher thn in the logging res ccepted for res with high logging intensity (Fig. 1). Higher sl re in the logging re indicted tht logging ctivities tended to increse the sl re. Also, ccording to Fig. 1c the percentge of cnopy cover in the non-logged re ws significntly higher thn in logged res (low, medium, nd high logging intensities). The lower percentge of cnopy cover in the logging re indicted tht logging ctivities tended to decrese the cnopy re. Also the results of Duncn s test for comprison of diversity, richness, nd evenness indices etween non-logged nd logging res indicte tht plnt iodiversity indices tended to increse, so tht this increse will e reched to the highest point in medium logging intensity (Figs 2 c). Some differences in stem density, sl re nd cnopy cover were recorded in logged re compred to non-logged re. Some reserchers hve reported similr results (Ckir et l. 2010). Also, the present study shows tht logging ctivities ffected the tree diversity indices. The low vlues of iodiversity indices were otined in high logging intensity, which precludes the existence of forests in dvnced or decdent stges of devel- Tle 3. ANOVA of the effect of logging intensity on stem density, sl re, cnopy cover, diversity, richness nd evenness Vrile F 3, 119 P Stem density ** Bsl re ** Cnopy cover ** Diversity ** Richness ** Evenness ** **P < 0.01 J. FOR. SCI., 63, 2017 (4):

4 () Stem density (No. per h) () Bsl re (m 2 h 1 ) (c) Cnopy cover (%) Non-logged Low Medium High c Logging intensity Fig. 1. Stem density (), sl re (), percentge of cnopy cover (c) in non-logged nd logged res d () Diversity index () Richness index (c) Eveness index Non-logged Low Medium High Fig. 2. The vlues of diversity (), richness (), evenness (c) index in non-logged nd logged res Logging intensity c opment nd negtively impcts on the undnce of these elements tht re considered criticl for forest iodiversity, s hs een oserved y numerous uthors (Green, Peterken 1997; Rowlnd et l. 2005). Hnsen et l. (1991) reported similr results for intensively mnged forests in the Costl Northwest of the United Sttes, where they found higher undnce of lrge trees nd lrge sngs in nturl forests thn in mnged stnds. This result ws supported in prt y other uthors (Rowlnd et l. 2005). Mny studies hve pointed out tht vegettion ws ffected y logging ctivities, nd they noticed negtive correltion etween logging intensity nd plnt cover, species richness nd species diversity (Srh, Zhevelev 2007; Ckir et l. 2010). Our results complete other studies on chnges in plnt popultions nd communities due to logging ctivities (Nuzzo 1995; Frris 1998; McMilln, Lrson 2002; Rusterholz et l. 2004). CONCLUSIONS According to the results of the present study, the logging intensity in the studied region should e monitored to improve the quntity nd qulity of the iodiversity, it is importnt for developing restortion plns in forest sites ffected y intensive logging ctivities. 170 J. FOR. SCI., 63, 2017 (4):

5 The results proved tht the stem density in medium logging intensity is t the highest level compred to other tretments. According to the results the sl re in low nd medium logging intensity is t the highest level compred to non-logged nd high logging intensity. The results of the present study showed tht the percentge of cnopy cover in non-logged res nd low logging intensity is t the highest level compred to other tretments. The results of the present study indicted tht the vlues of diversity index in low nd medium logging intensities re t the highest level compred to other tretments. The results of the present study proved tht the vlues of richness index in low nd medium logging intensities re t the highest level compred to other tretments. The results of the present study indicted tht the vlues of evenness index in low nd medium logging intensities re t the highest level compred to other tretments. As commercil logging in Cspin forests is pplied y nturl resources policy mkers, it cn e concluded tht medium-level logging intensity my e eneficil for moving towrd sustinle forest mngement regrding ecologicl nd economic spects. Acknowledgment The uthors would like to thnk the dministrtion of the Shfroud Compny for field coopertion during colleting the reserch dt. References Bw K.S., Seidler R. (1998): Nturl forest mngement nd conservtion of iodiversity in tropicl forests. Conservtion Biology, 12: Behjou F.K., Mollshi O.G. (2013): A prcticl smpling strtegy for ssessing woody deris in Fndoghlou forest, Irn. Journl of Environmentl Science, 8: Ckir M., Mkineci E., Kumsli A. (2010): Comprtive study on soil properties in picnic nd undistured re of Belgrd forest, Istnul. Journl of Environmentl Biology, 31: De Wsseige C., Defourny P. (2004): Remote sensing of selective logging impct for tropicl forest mngement. Forest Ecology nd Mngement, 188: Deckker M., De Grf N.R.R. (2003): Pioneer nd climx tree regenertion following selective logging with silviculture in Surinme. Forest Ecology nd Mngement, 172: Drigo R., Lsserre B., Mrchetti M. (2009): Tropicl lnd cover chnge: Ptterns, trends nd impcts. Plnt Biosystems, 143: Erikson L., Annik M., Nordlund A., Olsson O., Westin K. (2012): Recretion in different forest settings: A scene preference study. Forests, 3: Frris M.A. (1998): The effects of rock climing on the vegettion of three Minnesot cliff systems. Cndin Journl of Botny, 76: Grdner T.A., Brlow J., Chzdon R., Ewers R.M., Hrvey C.A., Peres C.A. (2009): Prospects for tropicl forest iodiversity in humn-modified world. Ecologicl Letter, 12: Gscon C., Mesquit R., Higuchi N., Crle B.J., Hrtshorn G.S., Bowles I.A., Rice R.E., Mittermeier R.A., D Fonsec G.A.B. (1998): Logging on in the rin forests. Science, 281: Green P., Peterken G.F. (1997): Vrition in the mount of ded wood in the woodlnds of the Lower Wye Vlley, UK in reltion to the intensity of mngement. Forest Ecology nd Mngement, 98: Hlpern C.B., Spies T.A. (1995): Plnt species diversity in nturl nd mnged forests of the Pcific Northwest. Ecologicl Applictions, 5: Hnsen A.J., Spies T.A., Swnson F.J., Ohmnn J.L. (1991): Conserving iodiversity in mnged forests, lessons from nturl forests. Bioscience, 41: Hegetschweiler K.T., Loon N.V., Ryser A., Rusterholz H.P., Bur B. (2009): Effects of fireplce use on forest vegettion nd mount of woody deris in suurn forests in Northwestern Switzerlnd. Environmentl Mngement, 43: Lindenmyer D.B., Mrgules C.R., Botkin D.B. (2000): Indictors of iodiversity for ecologiclly sustinle forest mngement. Conservtion Biology, 14: McMilln M., Lrson D.W. (2002): Effects of rock climing on the vegettion of the Nigr escrpment in southern Ontrio, Cnd. Conservtion Biology, 16: Niemel J. (1999): Ecology nd urn plnning. Biodiversity Conservtion, 8: Nuzzo V.A. (1995): Effects of rock climing on cliff goldenrod (Solidgo sciphil Steele) in northwest Illinois. Americn Midlnd Nturlist, 133: Pimentel D., Stchow U., Tkcs D.A., Bruker H.W., Dums A.R., Meney J.J., O Neil J.A.S., Onsi D.E., Corzilius D.B. (1992): Conserving iologicl diversity in griculturl/ forestry systems. Bioscience, 42: Putz F.E., Zuidem P.A., Synnott T., Pe-Clros M., Pinrd M.A., Sheil D. (2012): Sustining conservtion vlues in selectively logged tropicl forests: The ttined nd the ttinle. Conservtion Letter, 5: Rmetsteiner E., Simul M. (2003): Forest certifiction n instrument to promote sustinle forest mngement. Journl of Environmentl Mngement, 67: J. FOR. SCI., 63, 2017 (4):

6 Rowlnd E.L., White A.S., Willim H.L. (2005): MP754: A Literture Review of the Effects of Intensive Forestry on Forest Structure nd Plnt Community Composition t the Stnd nd Lndscpe Levels. Orono, Miscellneous Pulictions: 28. Rusterholz H.P., Miiller S.W., Bur B. (2004): Effects of rock climing on plnt communities on exposed limestone cliffs in the Swiss Jur Mountins. Applied Vegettion Science, 7: Sh H.K., Srkr A., Hldr P. (2011): Effects of nthropogenic disturnces on the diversity nd composition of the cridid fun of sites in the dry deciduous forest of West Bengl, Indi. Journl of Biodiversity nd Ecologicl Sciences, 1: Srh P., Zhevelev H.M. (2007): Effect of visitors pressure on soil nd vegettion in severl different micro-environments in urn prks in Tel Aviv. Lndscpe Urn Pln, 83: Spies T.A., Turner M.G. (1999): Dynmic forest mosics. In: Hunter M.L. (ed.): Mintining Biodiversity in Forest Ecosystems. Cmridge, Cmridge University Press: Tynsong H., Tiwri B.K. (2010): Diversity of plnt species in recnut groforests of south Mghly, north-est Indi. Journl of Forestry Reserch, 21: Received for puliction Septemer 1, 2016 Accepted fter corrections Jnury 16, J. FOR. SCI., 63, 2017 (4):