They explained that elk in Yellowstone used to browse unmolested on young aspen and willow growing near the banks of streams, a behavior that prevented the saplings from reaching mature stages and increased the possibility of soil erosion.
1	They	they	PRON	PRP	Case=Nom|Number=Plur|Person=3|PronType=Prs	2	nsubj	2:nsubj	_
2	explained	explain	VERB	VBD	Mood=Ind|Number=Plur|Person=3|Tense=Past|VerbForm=Fin	0	root	0:root	_
3	that	that	SCONJ	IN	_	7	mark	7:mark	_
4	elk	elk	NOUN	NNS	Number=Plur	7	nsubj	7:nsubj|9:nsubj:xsubj|10:nsubj:xsubj	_
5	in	in	ADP	IN	_	6	case	6:case	_
6	Yellowstone	Yellowstone	PROPN	NNP	Number=Sing	4	nmod	4:nmod:in	_
7	used	use	VERB	VBD	Mood=Ind|Number=Plur|Person=3|Tense=Past|VerbForm=Fin	2	ccomp	2:ccomp	_
8	to	to	PART	TO	_	9	mark	9:mark	_
9	browse	browse	VERB	VB	VerbForm=Inf	7	xcomp	7:xcomp	_
10	unmolested	unmolested	ADJ	JJ	Degree=Pos	9	xcomp	9:xcomp	_
11	on	on	ADP	IN	_	13	case	13:case	_
12	young	young	ADJ	JJ	Degree=Pos	13	amod	13:amod	_
13	aspen	aspen	NOUN	NN	Number=Sing	9	obl	9:obl:on	_
14	and	and	CCONJ	CC	_	15	cc	15:cc	_
15	willow	willow	NOUN	NN	Number=Sing	13	conj	9:obl:on|13:conj:and	_
16	growing	grow	VERB	VBG	VerbForm=Ger	13	acl	13:acl	_
17	near	near	ADP	IN	_	19	case	19:case	_
18	the	the	DET	DT	Definite=Def|PronType=Art	19	det	19:det	_
19	banks	bank	NOUN	NNS	Number=Plur	16	obl	16:obl:near	_
20	of	of	ADP	IN	_	21	case	21:case	_
21	streams	stream	NOUN	NNS	Number=Plur	19	nmod	19:nmod:of	SpaceAfter=No
22	,	,	PUNCT	,	_	9	punct	9:punct	_
23	a	a	DET	DT	Definite=Ind|PronType=Art	24	det	24:det	_
24	behavior	behavior	NOUN	NN	Number=Sing	9	appos	9:appos|26:nsubj|34:nsubj	_
25	that	that	PRON	WDT	PronType=Rel	26	nsubj	24:ref	_
26	prevented	prevent	VERB	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	24	acl:relcl	24:acl:relcl	_
27	the	the	DET	DT	Definite=Def|PronType=Art	28	det	28:det	_
28	saplings	sapling	NOUN	NNS	Number=Plur	26	obj	26:obj	_
29	from	from	SCONJ	IN	_	30	mark	30:mark	_
30	reaching	reach	VERB	VBG	VerbForm=Ger	26	advcl	26:advcl:from	_
31	mature	mature	ADJ	JJ	Degree=Pos	32	amod	32:amod	_
32	stages	stage	NOUN	NNS	Number=Plur	30	obj	30:obj	_
33	and	and	CCONJ	CC	_	34	cc	34:cc	_
34	increased	increase	VERB	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	26	conj	24:acl:relcl|26:conj:and	_
35	the	the	DET	DT	Definite=Def|PronType=Art	36	det	36:det	_
36	possibility	possibility	NOUN	NN	Number=Sing	34	obj	34:obj	_
37	of	of	ADP	IN	_	39	case	39:case	_
38	soil	soil	NOUN	NN	Number=Sing	39	compound	39:compound	_
39	erosion	erosion	NOUN	NN	Number=Sing	36	nmod	36:nmod:of	SpaceAfter=No
40	.	.	PUNCT	.	_	2	punct	2:punct	_
