七姊妹(mei)山自然保護區地(di)(di)處武陵山余脈,位(wei)于湖(hu)北(bei)省恩(en)施土家族(zu)苗族(zu)自治州(zhou)宣恩(en)縣(xian)的(de)東(dong)部(bu),其東(dong)與鶴峰縣(xian)交界,南與湖(hu)南省桑植縣(xian)毗連,北(bei)與恩(en)施市(shi)相鄰。區內自然環境獨(du)特,地(di)(di)貌類型多(duo)樣,珍稀野(ye)生(sheng)動植物(wu)(wu)(wu)資源豐富,屬中(zhong)(zhong)(zhong)國(guo)(guo)(guo)三大特有現象中(zhong)(zhong)(zhong)心(xin)之一的(de)“川東(dong)-鄂西特有現象中(zhong)(zhong)(zhong)心(xin)”的(de)核心(xin)地(di)(di)帶,區內自然環境獨(du)特,地(di)(di)貌類型多(duo)樣,生(sheng)物(wu)(wu)(wu)多(duo)樣性(xing)(xing)十分豐富,被《中(zhong)(zhong)(zhong)國(guo)(guo)(guo)生(sheng)物(wu)(wu)(wu)多(duo)樣性(xing)(xing)保護行動計劃》和《中(zhong)(zhong)(zhong)國(guo)(guo)(guo)生(sheng)物(wu)(wu)(wu)多(duo)樣性(xing)(xing)國(guo)(guo)(guo)情研(yan)究報告》列(lie)為(wei)中(zhong)(zhong)(zhong)國(guo)(guo)(guo)優先保護領(ling)域和具有全球意義的(de)生(sheng)物(wu)(wu)(wu)多(duo)樣性(xing)(xing)關(guan)鍵地(di)(di)區。
七姊(zi)妹山國家級自然保(bao)護區(qu)的建(jian)立,有利于對原始(shi)珙桐純(chun)林(lin)群落(luo)、泥炭蘚(xian)森林(lin)沼澤(ze)濕(shi)地以及華南(nan)虎等大(da)型貓科動物(wu)棲息地的保(bao)護。
湖(hu)北(bei)(bei)七姊妹山國家級(ji)自然保(bao)護區總(zong)面(mian)(mian)(mian)積34550公(gong)頃(qing)(qing),其中核心區面(mian)(mian)(mian)積11560公(gong)頃(qing)(qing),緩沖區面(mian)(mian)(mian)積11700公(gong)頃(qing)(qing),實驗區面(mian)(mian)(mian)積11290公(gong)頃(qing)(qing)。保(bao)護區位于(yu)湖(hu)北(bei)(bei)省宣恩縣境內,范圍在(zai)東經109°38′30″—109°47′00″,北(bei)(bei)緯29°39′30″—30°05′15″之間。
東自椿(chun)木營鄉張家灣(wan)主(zhu)(zhu)峰(feng)起,向南(nan)經小(xiao)窩(wo)盔(kui)主(zhu)(zhu)峰(feng)、穿孔子、李老四灣(wan)山(shan)梁(liang),至(zhi)木營村河西山(shan)脊,再轉向東3公里(li)至(zhi)宣恩(en)縣與(yu)鶴峰(feng)縣的(de)縣界,再沿縣界南(nan)下至(zhi)湘鄂兩省省界,經省界與(yu)湖南(nan)八大公山(shan)國家級自然保護(hu)區交界,沿省界南(nan)下至(zhi)海(hai)拔1418.2米的(de)土地埡,向西經風車口(kou)、桂竹梁(liang),至(zhi)沙道溝鎮紅旗(qi)坪村蘭花洞北面1185米主(zhu)(zhu)峰(feng)。
西界(jie)(jie)為(wei)向(xiang)東(dong)(dong)北(bei)(bei)(bei)經(jing)廟(miao)灣(wan)、埡楠坪、茶(cha)樹堡、顧家(jia)(jia)(jia)埡,至火(huo)燒坪,再向(xiang)北(bei)(bei)(bei)經(jing)大(da)觀山、楊家(jia)(jia)(jia)河、核桃灣(wan)、周家(jia)(jia)(jia)壩、文家(jia)(jia)(jia)臺、茶(cha)園北(bei)(bei)(bei)山、五(wu)架(jia)山、大(da)坪山、蘆家(jia)(jia)(jia)界(jie)(jie),越過后龍山和大(da)峰(feng)尖,至保(bao)護(hu)區(qu)北(bei)(bei)(bei)面長潭河鄉貓(mao)子莊(zhuang)村的(de)杉樹堡;北(bei)(bei)(bei)界(jie)(jie)為(wei)向(xiang)東(dong)(dong)經(jing)木(mu)林溪至宣恩縣(xian)(xian)與恩施市的(de)交界(jie)(jie)處,再由縣(xian)(xian)界(jie)(jie)向(xiang)東(dong)(dong)南(nan)經(jing)樺(hua)桿坪西,至保(bao)護(hu)區(qu)東(dong)(dong)北(bei)(bei)(bei)椿木(mu)營鄉張家(jia)(jia)(jia)灣(wan)海拔1938米的(de)主峰(feng)止。
七(qi)姊妹山(shan)是宣恩(en)縣的第一高山(shan),屬武陵山(shan)脈,距宣恩(en)縣城約40km,總(zong)面(mian)積150km2。因七(qi)峰(feng)依次排列(lie)似傳(chuan)說中的七(qi)仙女而得(de)名(ming),其高烽火燒(shao)堡2014.5m,低處(chu)(chu)巴山(shan)坪1230m,相對海(hai)拔734.5m。七(qi)姊妹相傍(bang)相依,在霧海(hai)霞光(guang)中時隱時現,好似七(qi)仙女踏著云簇一面(mian)俯瞰一面(mian)嬉笑。七(qi)姊妹山(shan),群峰(feng)崢(zheng)嶸,怪(guai)石頻矗,溪(xi)溝(gou)縱橫(heng)交錯,有常流(liu)溪(xi)溝(gou)8條,瀑布4處(chu)(chu)。
保護(hu)區(qu)總(zong)面積34550hm2,轄區(qu)內高海(hai)拔為2014.5m,低(di)海(hai)拔650m。保護(hu)區(qu)地處長江中游(you)第二支流清江的(de)上游(you)和洞庭湖(hu)沅江一級(ji)支流酉水發源地的(de)交匯處,此保護(hu)區(qu)處于(yu)中國地勢第二節體(ti)向(xiang)第三節體(ti)的(de)過度區(qu)域,是(shi)中國中亞熱(re)帶(dai)向(xiang)北(bei)亞熱(re)帶(dai)的(de)過度地區(qu),同時也屬中國三大特(te)有現象(xiang)中心之一的(de)“川東-鄂西特(te)有現象(xiang)中心”的(de)核(he)心地帶(dai),區(qu)內自(zi)然環境獨特(te),地貌(mao)類型多(duo)樣(yang)(yang),生物多(duo)樣(yang)(yang)性十分豐富。
隨海(hai)(hai)拔(ba)高(gao)程的(de)變(bian)化,呈明(ming)顯的(de)垂直差異(yi)海(hai)(hai)拔(ba)800米以下的(de)低(di)山帶,四(si)季分(fen)明(ming),冬暖夏熱,雨(yu)熱同步,光(guang)溫(wen)(wen)(wen)互補,年(nian)(nian)(nian)均(jun)(jun)氣(qi)溫(wen)(wen)(wen)15.8℃,無(wu)霜期(qi)294天,年(nian)(nian)(nian)降水(shui)(shui)量1491.3毫(hao)米,年(nian)(nian)(nian)日照時(shi)數(shu)1136.2小(xiao)時(shi)。海(hai)(hai)拔(ba)800—1200米的(de)二高(gao)山地(di)帶,春遲(chi)秋早,濕潤多雨(yu),光(guang)溫(wen)(wen)(wen)不足,年(nian)(nian)(nian)均(jun)(jun)氣(qi)溫(wen)(wen)(wen)13.7℃,無(wu)霜期(qi)263天,年(nian)(nian)(nian)降水(shui)(shui)量1635.3毫(hao)米,年(nian)(nian)(nian)日照時(shi)數(shu)1212.4小(xiao)時(shi)。海(hai)(hai)拔(ba)1200米以上的(de)高(gao)山地(di)帶,氣(qi)候冷涼(liang),冬長夏短,易澇少旱,年(nian)(nian)(nian)均(jun)(jun)氣(qi)溫(wen)(wen)(wen)8.9℃,無(wu)霜203天,年(nian)(nian)(nian)降水(shui)(shui)量1867毫(hao)米,年(nian)(nian)(nian)日照時(shi)數(shu)1519.9小(xiao)時(shi)。
動物(wu)資源(yuan)富有,珍稀植(zhi)物(wu)繁(fan)多(duo)。綠裝素(su)裹的小(xiao)七秭妹(mei)山(shan),挺(ting)拔俊秀的大(da)七姊妹(mei)山(shan),凌空突兀的剪刀夾峰(feng)(feng)(feng),金獅迎(ying)客的石(shi)柱(zhu)峰(feng)(feng)(feng),千(qian)姿百(bai)態,樹(shu)海茫(mang)(mang)茫(mang)(mang),流泉蜿(wan)蜒,飛瀑騰空,大(da)小(xiao)景觀(guan)點(dian)數(shu)以百(bai)計,將(jiang)整(zheng)個七姊妹(mei)山(shan)系繪(hui)成了(le)一幅壯麗的畫面(mian)。區內植(zhi)物(wu)垂直帶譜完整(zheng)、植(zhi)被保(bao)持完好,水量充沛(pei),山(shan)體、孤峰(feng)(feng)(feng)、怪石(shi)造型奇特,大(da)小(xiao)瀑布多(duo)姿多(duo)彩,是原始(shi)森林觀(guan)光探(tan)險旅游的勝地。
七姊妹(mei)山屬(shu)原(yuan)始森林。有(you)(you)維管束(shu)植(zhi)(zhi)物(wu)(wu)144科(ke)(ke)(ke)、428屬(shu)、892種(zhong)。其中(zhong)(zhong)(zhong)木本植(zhi)(zhi)物(wu)(wu)有(you)(you)90科(ke)(ke)(ke)、208屬(shu)、603種(zhong)。以殼斗科(ke)(ke)(ke)、樟科(ke)(ke)(ke)、薔(qiang)薇科(ke)(ke)(ke)、杜鵑科(ke)(ke)(ke)、山茶科(ke)(ke)(ke)、山礬科(ke)(ke)(ke)、七葉樹科(ke)(ke)(ke)、珙(gong)(gong)(gong)(gong)桐科(ke)(ke)(ke)為主(zhu)。珍貴植(zhi)(zhi)物(wu)(wu)中(zhong)(zhong)(zhong),屬(shu)國(guo)家一(yi)級(ji)保(bao)護(hu)的(de)(de)一(yi)種(zhong),二(er)級(ji)保(bao)護(hu)的(de)(de)6種(zhong),三級(ji)保(bao)護(hu)的(de)(de)10種(zhong),湖北特有(you)(you)植(zhi)(zhi)物(wu)(wu)30種(zhong)。國(guo)家一(yi)級(ji)重點保(bao)護(hu)的(de)(de)珙(gong)(gong)(gong)(gong)桐,分布面(mian)積達(da)一(yi)萬余畝(mu),其中(zhong)(zhong)(zhong)集中(zhong)(zhong)(zhong)分布面(mian)積3499畝(mu)。珙(gong)(gong)(gong)(gong)桐,是世界(jie)著(zhu)名孑(jie)遺植(zhi)(zhi)物(wu)(wu)和(he)觀賞植(zhi)(zhi)物(wu)(wu),每逢春(chun)夏(xia)之(zhi)交,正是珙(gong)(gong)(gong)(gong)桐的(de)(de)開花(hua)時(shi)節(jie),滿(man)山遍野(ye)的(de)(de)花(hua)朵,好似(si)成(cheng)群(qun)的(de)(de)白鴿棲(qi)息在枝頭,所以,珙(gong)(gong)(gong)(gong)桐俗稱鴿子樹。山中(zhong)(zhong)(zhong)有(you)(you)野(ye)生動物(wu)(wu)146種(zhong),其中(zhong)(zhong)(zhong)獸類(lei)45種(zhong),鳥類(lei)64種(zhong),爬(pa)行類(lei)19種(zhong),兩棲(qi)類(lei)18種(zhong)。屬(shu)國(guo)家保(bao)護(hu)的(de)(de)珍稀動物(wu)(wu),有(you)(you)白冠長(chang)尾雉、紅腹錦雞、大(da)鯢(娃娃魚(yu))、水獺、大(da)靈(ling)貓、小靈(ling)貓、獐、林麝、蘇(su)門羚(ling)等(deng)。還有(you)(you)實用(yong)價值較高(gao)的(de)(de)果(guo)子貍、穿山甲、狗獾、黑熊、黃麂等(deng)。
七(qi)姊妹山,藥用(yong)植物(wu)分布面積(ji)較廣。較為突出的(de)有(you)天(tian)麻(ma)、黃連、芍藥、黨參、竹節(jie)人參、扣子七(qi)、算盤七(qi)、黃精、絞股蘭等。野生花(hua)(hua)草種(zhong)類繁(fan)多,有(you)觀賞價值(zhi)的(de)約100余種(zhong),如杜鵑花(hua)(hua)就(jiu)有(you)18種(zhong),珙桐花(hua)(hua)漫山遍(bian)野,蘭草、木蘭、吊(diao)鐘花(hua)(hua)、紫(zi)薇、紫(zi)莖、野百合(he),處處可見。
七姊妹山自然保(bao)(bao)護區(qu)(qu)(qu)蕨(jue)(jue)類(lei)(lei)植物區(qu)(qu)(qu)系(xi)(xi)地(di)(di)(di)(di)理及資源開發研(yan)究(jiu)運(yun)用植物區(qu)(qu)(qu)系(xi)(xi)地(di)(di)(di)(di)理分(fen)(fen)析方法對(dui)七姊妹山自然保(bao)(bao)護區(qu)(qu)(qu)的(de)(de)蕨(jue)(jue)類(lei)(lei)植物區(qu)(qu)(qu)系(xi)(xi)特征進行研(yan)究(jiu)。科的(de)(de)地(di)(di)(di)(di)理區(qu)(qu)(qu)系(xi)(xi)分(fen)(fen)析表(biao)明,熱帶(dai)(dai)、亞熱帶(dai)(dai)成分(fen)(fen)高達58.3%,占主(zhu)導地(di)(di)(di)(di)位。屬的(de)(de)地(di)(di)(di)(di)理區(qu)(qu)(qu)系(xi)(xi)分(fen)(fen)析也表(biao)明了類(lei)(lei)似的(de)(de)趨勢。種(zhong)的(de)(de)地(di)(di)(di)(di)理區(qu)(qu)(qu)系(xi)(xi)分(fen)(fen)析表(biao)明,除了熱帶(dai)(dai)、亞熱帶(dai)(dai)成分(fen)(fen)占有(you)較高比(bi)例外(wai),溫帶(dai)(dai)分(fen)(fen)布(bu)(bu)的(de)(de)種(zhong)也具(ju)有(you)較高的(de)(de)比(bi)例,占非世界(jie)廣布(bu)(bu)種(zhong)的(de)(de)31.2%。特別是世界(jie)溫帶(dai)(dai)分(fen)(fen)布(bu)(bu)的(de)(de)種(zhong)占較高比(bi)例,達24.2%,這反(fan)映了溫帶(dai)(dai)成分(fen)(fen)的(de)(de)重(zhong)要地(di)(di)(di)(di)位。
七(qi)姊妹山(shan)蕨(jue)類植物資源(yuan)豐富,可區分(fen)為藥用、觀賞、食用、指(zhi)示(shi)類植物等幾(ji)大類。各種蕨(jue)類植物資源(yuan)顯示(shi)了(le)廣闊(kuo)的(de)利用前景。七(qi)姊妹山(shan)食用蕨(jue)類植物的(de)大特(te)色是“富硒”除了(le)抗氧化(hua)等生理與營(ying)養(yang)作(zuo)用外(wai),還抗鉛、汞(gong)、鎘、鉈、銀(yin)等重金屬(shu)毒害元素。
1988年9月13日,新華(hua)社播發新聞通稿,華(hua)中師(shi)范(fan)大學在對(dui)恩(en)施(shi)州宣恩(en)縣七姊(zi)妹山地(di)區(qu)進行科學考(kao)察時,驚(jing)喜地(di)發現大面(mian)積原(yuan)始珙桐群(qun)落!
珙(gong)(gong)桐(tong)是遠古侏羅紀(ji)第三紀(ji)冰川活動遺留下(xia)來的(de)(de)(de)孑(jie)遺植(zhi)(zhi)物,一(yi)度被世界生(sheng)物學(xue)(xue)(xue)界列(lie)入“消(xiao)亡(wang)(wang)”名單。瀕(bin)臨消(xiao)亡(wang)(wang)的(de)(de)(de)珙(gong)(gong)桐(tong)大(da)面積現(xian)身(shen)鄂西(xi)南(nan)!這帶給生(sheng)物學(xue)(xue)(xue)界的(de)(de)(de)震撼(han)不亞于一(yi)枚(mei)重磅炸(zha)彈的(de)(de)(de)爆炸(zha),學(xue)(xue)(xue)界的(de)(de)(de)研(yan)究(jiu)者們立刻行動起來了,自1989年開始,華中(zhong)(zhong)師范(fan)大(da)學(xue)(xue)(xue)、湖(hu)(hu)北大(da)學(xue)(xue)(xue)、湖(hu)(hu)南(nan)師范(fan)大(da)學(xue)(xue)(xue)、北京林業大(da)學(xue)(xue)(xue)、中(zhong)(zhong)科(ke)院武漢植(zhi)(zhi)物研(yan)究(jiu)所、湖(hu)(hu)北民族(zu)學(xue)(xue)(xue)院等科(ke)研(yan)單位(wei)和大(da)專(zhuan)院校(xiao)的(de)(de)(de)專(zhuan)家教(jiao)授,多(duo)次(ci)組織科(ke)研(yan)隊伍進入恩施(shi)州(zhou)宣(xuan)恩縣(xian)七姊妹(mei)(mei)山(shan),開始了揭開七姊妹(mei)(mei)山(shan)神秘(mi)面紗的(de)(de)(de)探索之(zhi)旅,發表(biao)了《鄂西(xi)七姊妹(mei)(mei)山(shan)珙(gong)(gong)桐(tong)群(qun)(qun)落(luo)(luo)研(yan)究(jiu)》、《宣(xuan)恩七姊妹(mei)(mei)山(shan)珙(gong)(gong)桐(tong)群(qun)(qun)落(luo)(luo)種(zhong)間聯(lian)結(jie)分析》、《湖(hu)(hu)北七姊妹(mei)(mei)山(shan)珙(gong)(gong)桐(tong)種(zhong)間結(jie)構研(yan)究(jiu)》和《珙(gong)(gong)桐(tong)群(qun)(qun)落(luo)(luo)中(zhong)(zhong)珙(gong)(gong)桐(tong)種(zhong)群(qun)(qun)與主要共生(sheng)樹木種(zhong)群(qun)(qun)間聯(lian)結(jie)關(guan)系的(de)(de)(de)研(yan)究(jiu)》、《七姊妹(mei)(mei)山(shan)自然(ran)保護區珍稀植(zhi)(zhi)物資源研(yan)究(jiu)》等一(yi)系列(lie)科(ke)技論文。
同(tong)時,學界的(de)(de)研(yan)(yan)究(jiu)目光也鎖定了整個七姊(zi)妹山,各科(ke)(ke)(ke)研(yan)(yan)機構、大(da)專院校相繼(ji)在七姊(zi)妹山開展了珍(zhen)稀(xi)瀕(bin)危植物(wu)及土(tu)著物(wu)種(zhong)(zhong)的(de)(de)調查、鳥類調查、珍(zhen)稀(xi)瀕(bin)危物(wu)種(zhong)(zhong)監(jian)測項(xiang)目、亞高山泥(ni)炭蘚沼澤濕地資源的(de)(de)研(yan)(yan)究(jiu)等專題研(yan)(yan)究(jiu)。對大(da)面積的(de)(de)原始珙桐純林、頻繁出(chu)現的(de)(de)大(da)型(xing)貓科(ke)(ke)(ke)動物(wu)蹤跡、豐富的(de)(de)林麝資源和蘭科(ke)(ke)(ke)植物(wu)資源等進行研(yan)(yan)究(jiu)。一時間(jian),宣恩七姊(zi)妹山成了國內外生物(wu)學界關注的(de)(de)焦點之一。
珙(gong)桐(tong)(tong)是(shi)(shi)中國(guo)(guo)特有(you)(you)(you)的(de)(de)(de)第三紀古熱(re)帶植物(wu)(wu)區系孑(jie)遺(yi)植物(wu)(wu),國(guo)(guo)家一級重點保護植物(wu)(wu)。目前(qian)珙(gong)桐(tong)(tong)主(zhu)要間斷分(fen)布(bu)于中國(guo)(guo)亞熱(re)帶山地,并(bing)多呈零星分(fen)布(bu)。同時,罕見的(de)(de)(de)原(yuan)(yuan)始珙(gong)桐(tong)(tong)純林(lin)及大(da)型貓科動物(wu)(wu)生(sheng)存環境,都(dou)具有(you)(you)(you)國(guo)(guo)際(ji)公(gong)(gong)認的(de)(de)(de)極高保護價值(zhi)。研究者們在(zai)七姊妹(mei)山發(fa)現(xian),珙(gong)桐(tong)(tong)群落(luo)分(fen)布(bu)約有(you)(you)(you)500公(gong)(gong)頃,其中有(you)(you)(you)200公(gong)(gong)頃是(shi)(shi)保存完好(hao)的(de)(de)(de)原(yuan)(yuan)始珙(gong)桐(tong)(tong)群落(luo),并(bing)且這片原(yuan)(yuan)始珙(gong)桐(tong)(tong)群落(luo)五級立木齊全,種源充足(zu),自然更新(xin)能力(li)強(qiang),無人(ren)為干擾,構(gou)成(cheng)了(le)穩定的(de)(de)(de)森林(lin)生(sheng)態(tai)系統。更加讓人(ren)驚(jing)喜的(de)(de)(de)是(shi)(shi),七姊妹(mei)山及其周邊(bian)地區,曾經是(shi)(shi)華南虎、金錢豹(bao)、云豹(bao)等(deng)大(da)型貓科動物(wu)(wu)的(de)(de)(de)集中分(fen)布(bu)區域。近年(nian)來,隨著生(sheng)態(tai)環境的(de)(de)(de)逐(zhu)步好(hao)轉(zhuan),保護區及其周邊(bian)發(fa)現(xian)大(da)型貓科動物(wu)(wu)的(de)(de)(de)活動蹤跡越(yue)來越(yue)頻繁(fan)。
景區主要為喀斯特地(di)(di)貌,山(shan)體氣勢(shi)宏大,以七(qi)姊妹山(shan)為代表的絕壁孤峰卓然秀麗,象形(xing)山(shan)石眾(zhong)多(duo);區內(nei)原始林(lin)(lin)(lin)、次生林(lin)(lin)(lin)發(fa)育(yu),保存(cun)良好;這里海拔高(gao)差懸(xuan)殊,地(di)(di)形(xing)復雜(za),溝谷切割(ge)較深,水量充沛(pei),形(xing)成了眾(zhong)多(duo)各類型瀑(pu)布(bu),驚險(xian)刺激,蔚(yu)為壯觀;區內(nei)還有道教勝地(di)(di)中武當(dang),縣蘇維(wei)埃政府(fu)舊址,張難先隱(yin)居(ju)舊址,及龍馬山(shan)、仙(xian)人洞等自然與人文景觀。每逢(feng)春夏之交,珙桐開花(hua)(hua)時節,七(qi)姊妹山(shan)滿山(shan)遍野的花(hua)(hua)朵,好似成群的白鴿棲息(xi)在(zai)枝頭。七(qi)姊妹山(shan)景區內(nei)宜人的森林(lin)(lin)(lin)風光,茫(mang)茫(mang)林(lin)(lin)(lin)海,峽谷幽深,溪流湍急(ji),群峰聳峙,是人們探險(xian)尋勝和避暑消閑的勝地(di)(di)。
七(qi)姊(zi)妹山(shan)景區(qu)內七(qi)峰排列,疑似仙(xian)女下凡,數以百計的大小景點裝飾(shi)著整個(ge)七(qi)姊(zi)妹山(shan)系。1988年9月(yue),華(hua)中(zhong)師范大學(xue)在對七(qi)姊(zi)妹山(shan)地區(qu)進(jin)行科學(xue)考察時,發現大面積原(yuan)始珙桐(tong)(tong)群(qun)落(luo)。研究發現,珙桐(tong)(tong)群(qun)落(luo)分布(bu)約(yue)有500公頃,其中(zhong)有200公頃是(shi)保存完好的原(yuan)始珙桐(tong)(tong)群(qun)落(luo),并且這(zhe)片原(yuan)始珙桐(tong)(tong)群(qun)落(luo)五(wu)級立木齊全(quan),種源充足,自然更新能力強,無人為干擾,構(gou)成(cheng)了穩定的森林生態系統。七(qi)姊(zi)妹山(shan)及其周邊(bian)地區(qu),曾經是(shi)華(hua)南虎、金(jin)錢豹、云豹等大型(xing)貓科動物的集中(zhong)分布(bu)區(qu)域。
統計表明(ming):區內分布(bu)有國(guo)家(jia)珍稀瀕危保(bao)護(hu)(hu)植(zhi)(zhi)(zhi)物(wu)41種(zhong),其中(zhong)國(guo)家(jia)重(zhong)點保(bao)護(hu)(hu)植(zhi)(zhi)(zhi)物(wu)28種(zhong),國(guo)家(jia)Ⅰ級重(zhong)點保(bao)護(hu)(hu)植(zhi)(zhi)(zhi)物(wu)有銀杏、紅豆(dou)杉、南(nan)方(fang)紅豆(dou)杉、鐘萼木(mu)、莼菜、珙桐、光葉珙桐共(gong)7種(zhong);國(guo)家(jia)Ⅱ級重(zhong)點保(bao)護(hu)(hu)植(zhi)(zhi)(zhi)物(wu)21種(zhong),重(zhong)點保(bao)護(hu)(hu)植(zhi)(zhi)(zhi)物(wu)總(zong)數占(zhan)湖北省國(guo)家(jia)重(zhong)點保(bao)護(hu)(hu)植(zhi)(zhi)(zhi)物(wu)總(zong)數46種(zhong)的60.9%。
保(bao)(bao)護(hu)(hu)區內分布有(you)國家重(zhong)點保(bao)(bao)護(hu)(hu)動物(wu)(wu)共56種,其(qi)中Ⅰ級(ji)重(zhong)點保(bao)(bao)護(hu)(hu)動物(wu)(wu)有(you)豹、云豹、金(jin)雕、林(lin)麝(she)等5種,Ⅱ級(ji)重(zhong)點保(bao)(bao)護(hu)(hu)動物(wu)(wu)51種。近年來,隨著生態環境的逐步好轉,保(bao)(bao)護(hu)(hu)區及其(qi)周(zhou)邊發現大型貓科動物(wu)(wu)的活(huo)動蹤跡越(yue)來越(yue)頻繁(fan)。
七(qi)姊(zi)(zi)妹山中(zhong)的大(da)面積珙(gong)桐群(qun)落帶(dai)給世人(ren)的驚喜還沒(mei)消退(tui),自(zi)然(ran)保(bao)(bao)護(hu)區(qu)(qu)的建立(li)(li)就提上了(le)政府(fu)(fu)工(gong)作議程(cheng)。1990年(nian),宣恩縣政府(fu)(fu)批準成立(li)(li)了(le)七(qi)姊(zi)(zi)妹山縣級(ji)(ji)自(zi)然(ran)保(bao)(bao)護(hu)區(qu)(qu),下設七(qi)姊(zi)(zi)妹山縣級(ji)(ji)自(zi)然(ran)保(bao)(bao)護(hu)區(qu)(qu)管理站。2002年(nian),湖北(bei)省政府(fu)(fu)批準成立(li)(li)湖北(bei)七(qi)姊(zi)(zi)妹山省級(ji)(ji)自(zi)然(ran)保(bao)(bao)護(hu)區(qu)(qu)。2008年(nian)3月,喜訊傳來,該自(zi)然(ran)保(bao)(bao)護(hu)區(qu)(qu)又再升一級(ji)(ji),成為(wei)國家級(ji)(ji)自(zi)然(ran)保(bao)(bao)護(hu)區(qu)(qu)。至此,七(qi)姊(zi)(zi)妹山國家級(ji)(ji)自(zi)然(ran)保(bao)(bao)護(hu)區(qu)(qu)總(zong)面積達34550公(gong)頃,其(qi)(qi)中(zhong)核心區(qu)(qu)11560公(gong)頃,緩沖區(qu)(qu)11700公(gong)頃,實驗區(qu)(qu)11290公(gong)頃。其(qi)(qi)主要保(bao)(bao)護(hu)對(dui)象有四(si)種,即典型的中(zhong)亞熱帶(dai)山地(di)常綠闊葉林生態系統(tong)、以(yi)珙(gong)桐為(wei)主的珍(zhen)稀瀕危(wei)植物(wu)及其(qi)(qi)群(qun)落、以(yi)大(da)型貓科動(dong)物(wu)為(wei)主的珍(zhen)稀瀕危(wei)動(dong)物(wu)及其(qi)(qi)棲息環境(jing),以(yi)及保(bao)(bao)存完好的亞高山泥炭蘚沼澤(ze)濕地(di)。
七姊(zi)妹(mei)山自然保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)區(qu)(qu)是華中(zhong)(zhong)(zhong)地(di)區(qu)(qu)名副其(qi)實(shi)的(de)(de)(de)生(sheng)(sheng)物(wu)(wu)物(wu)(wu)種基因庫,具有極高的(de)(de)(de)科研和(he)學術價值(zhi)。首先是其(qi)原生(sheng)(sheng)性(xing)和(he)典型(xing)性(xing)。保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)區(qu)(qu)正處(chu)于(yu)中(zhong)(zhong)(zhong)國(guo)(guo)(guo)地(di)勢(shi)第(di)(di)二階梯向第(di)(di)三階梯的(de)(de)(de)過(guo)渡(du)地(di)帶(dai)(dai),又(you)剛好(hao)位于(yu)中(zhong)(zhong)(zhong)國(guo)(guo)(guo)自然地(di)理(li)區(qu)(qu)劃的(de)(de)(de)北(bei)亞熱帶(dai)(dai)與中(zhong)(zhong)(zhong)亞熱帶(dai)(dai)的(de)(de)(de)過(guo)渡(du)帶(dai)(dai)的(de)(de)(de)武陵山區(qu)(qu),在(zai)地(di)理(li)上具有典型(xing)性(xing)和(he)代表性(xing)。其(qi)次是生(sheng)(sheng)物(wu)(wu)多樣性(xing)。保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)區(qu)(qu)處(chu)于(yu)中(zhong)(zhong)(zhong)國(guo)(guo)(guo)中(zhong)(zhong)(zhong)亞熱帶(dai)(dai)季風潤濕氣候帶(dai)(dai),未受到第(di)(di)四紀冰(bing)川的(de)(de)(de)洗劫,現保(bao)(bao)(bao)存有5個植(zhi)被(bei)型(xing)組,9個植(zhi)被(bei)型(xing),30個原始(shi)植(zhi)物(wu)(wu)群系。再次是物(wu)(wu)種的(de)(de)(de)古(gu)老(lao)(lao)和(he)珍(zhen)稀瀕(bin)危性(xing)。保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)區(qu)(qu)是中(zhong)(zhong)(zhong)國(guo)(guo)(guo)第(di)(di)三紀植(zhi)物(wu)(wu)區(qu)(qu)系重(zhong)(zhong)要保(bao)(bao)(bao)存地(di)區(qu)(qu)之一,集中(zhong)(zhong)(zhong)分布了(le)中(zhong)(zhong)(zhong)國(guo)(guo)(guo)特有屬共(gong)32屬,這些(xie)(xie)特有屬中(zhong)(zhong)(zhong),有的(de)(de)(de)為單種屬,有的(de)(de)(de)為原始(shi)的(de)(de)(de)多心皮類,有的(de)(de)(de)在(zai)其(qi)他(ta)地(di)區(qu)(qu)已成(cheng)為化石(shi),這些(xie)(xie)特性(xing)均(jun)反映了(le)該區(qu)(qu)植(zhi)物(wu)(wu)區(qu)(qu)系的(de)(de)(de)古(gu)老(lao)(lao)性(xing)。統計表明:區(qu)(qu)內分布有國(guo)(guo)(guo)家(jia)(jia)(jia)珍(zhen)稀瀕(bin)危保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)植(zhi)物(wu)(wu)41種,其(qi)中(zhong)(zhong)(zhong)國(guo)(guo)(guo)家(jia)(jia)(jia)重(zhong)(zhong)點(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)植(zhi)物(wu)(wu)28種,國(guo)(guo)(guo)家(jia)(jia)(jia)Ⅰ級(ji)重(zhong)(zhong)點(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)植(zhi)物(wu)(wu)有銀杏、紅豆杉、南(nan)方(fang)紅豆杉、鐘萼(e)木、莼菜(cai)、珙桐、光(guang)葉(xie)珙桐共(gong)7種;國(guo)(guo)(guo)家(jia)(jia)(jia)Ⅱ級(ji)重(zhong)(zhong)點(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)植(zhi)物(wu)(wu)21種,重(zhong)(zhong)點(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)植(zhi)物(wu)(wu)總(zong)數占湖北(bei)省國(guo)(guo)(guo)家(jia)(jia)(jia)重(zhong)(zhong)點(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)植(zhi)物(wu)(wu)總(zong)數46種的(de)(de)(de)60.9%。保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)區(qu)(qu)內分布有國(guo)(guo)(guo)家(jia)(jia)(jia)重(zhong)(zhong)點(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)動(dong)物(wu)(wu)共(gong)56種,其(qi)中(zhong)(zhong)(zhong)Ⅰ級(ji)重(zhong)(zhong)點(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)動(dong)物(wu)(wu)有豹(bao)、云豹(bao)、金雕(diao)、林麝等5種,Ⅱ級(ji)重(zhong)(zhong)點(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)(hu)(hu)動(dong)物(wu)(wu)51種。
18個年頭,七(qi)姊妹(mei)山自然保(bao)護(hu)區(qu)(qu)躍(yue)升(sheng)兩級(ji),由“縣級(ji)”搖身成了“國(guo)(guo)家級(ji)”,從而成了公認的(de)“國(guo)(guo)寶”。這一(yi)過程,無不顯示著(zhu)該自然保(bao)護(hu)區(qu)(qu)在(zai)中國(guo)(guo)范圍內生態(tai)保(bao)護(hu)、科學研究等方面的(de)重要性(xing)。經(jing)過生物學界專家們研究得(de)出的(de)結(jie)論顯示:加強對(dui)七(qi)姊妹(mei)山自然保(bao)護(hu)區(qu)(qu)內原始珙(gong)桐(tong)(tong)群(qun)(qun)落的(de)保(bao)護(hu),對(dui)研究原始珙(gong)桐(tong)(tong)群(qun)(qun)落的(de)自然更新(xin)和演替、華中地區(qu)(qu)古地質年代(dai)和古氣候演變有著(zhu)極為重要的(de)保(bao)護(hu)價值。
七(qi)姊妹(mei)山自然(ran)保(bao)護(hu)區(qu)(qu)處于中(zhong)國(guo)地(di)勢第二階梯向第三(san)階梯的過渡區(qu)(qu)域,地(di)處中(zhong)國(guo)三(san)大特(te)有(you)(you)現象中(zhong)心之一的“川東—鄂西特(te)有(you)(you)現象中(zhong)心”的核心地(di)帶,位(wei)于中(zhong)國(guo)中(zhong)亞熱帶地(di)區(qu)(qu)生(sheng)物多樣(yang)(yang)(yang)性(xing)較為豐富的華中(zhong)地(di)區(qu)(qu),自然(ran)環境獨特(te),地(di)貌(mao)類型多樣(yang)(yang)(yang),野生(sheng)動(dong)植(zhi)物資源十分豐富,被《中(zhong)國(guo)生(sheng)物多樣(yang)(yang)(yang)性(xing)保(bao)護(hu)行(xing)動(dong)計劃》和《中(zhong)國(guo)生(sheng)物多樣(yang)(yang)(yang)性(xing)國(guo)情研究報告》列為中(zhong)國(guo)優(you)先保(bao)護(hu)領域和具有(you)(you)全球意義的生(sheng)物多樣(yang)(yang)(yang)性(xing)關鍵地(di)區(qu)(qu)。