KESEHATAN MERBAU (Intsia bijuga Colebr O. Kuntze) DAN INSTRUMEN PENILAIAN BIBIT BERKUALITAS ADAPTIF SEBAGAI UPAYA KONSERVASI PRODUKTIF DI HUTAN ALAM PROVINSI PAPUA BARAT
Susanti Tasik, Prof. Dr. Ir. Siti Muslimah, Widyastuti, M.Sc; Dr. Ir. Musyafa, M.Sc.; Prof. Priyono Suryanto, S. Hut., M.P., Ph.D
2023 | Disertasi | S3 Ilmu Kehutanan
Merbau (Intsia bijuga Colebr O. Kuntze) merupakan
jenis endemik yang mulai langka dan perlu upaya konkrit dalam meminimalisir
eksploitasinya yang berlebihan. Salah satu upaya yang ditempuh adalah dengan
mengkonservasi jenis ini, diluar habitat aslinya. Penelitian dilakukan di dua tempat yaitu habitat asli
merbau (in situ) dan di luar habitat aslinya (ex situ). Habitat
asli merbau yaitu kawasan Hutan Taman Wisata Alam Gunung Meja (HTWAGM) di
kabupaten Manokwari dan kawasan Hutan Bembab di kabupaten Manokwari Selatan. Habitat
diluar habitat asli yaitu di persemaian Manokwari (Balai Latihan Kehutanan)
mewakili musim pancaroba dan persemaian Fakultas Kehutanan UGM di Yogyakarta
mewakili musim hujan dan kemarau. Penelitian
berlangsung selama 6 bulan pengamatan. Penelitian bertujuan menilai performa
merbau (kualitas tapak, produktifitas, biodiversitas dan kesehatan) dihabitat
asli/in situ, mengetahui pertumbuhan dan perkembangan bibit merbau secara
generatif (in situ-ex situ) sebagai rujukan menyusun instrumen
penilaian bibit merbau yang sehat berkualitas dan adaptif, serta menentukan
prosfektifitas instrumen terhadap penilaian bibit merbau sehat berkualitas dan
adaptif dalam rangka mendukung konservasi produktif secara in situ- ex
situ. Analisis kualitas tapak, produktifitas, indeks biodiversitas dan
kualitas kesehatan dilakukan untuk menilai performa merbau pada sebaran
aslinya. Analisis media tanam, Analisis
anova satu dan dua arah terhadap pengaruh naungan dan interaksi musim dan
naungan terhadap komponen pertumbuhan pada persemaian in situ-ex situ, gangguan terhadap bibit (hama dan penyakit), penentuan
bibit merbau sehat berkualitas dan sehat adaptif dengan MultiDimensional
Scalling serta analisis prosfektifitasnya. Hasil penelitian menunjukkan merbau dapat tumbuh dengan baik
pada tapak dengan kualitas komponen dari rendah-sangat tinggi. Produktifitas
tegakan merbau tertinggi pada plot pengamatan di kawasan HTWAGM dengan nilai
LBDS 0,35 m2, volume 4,91 m3 pada kelas diameter
0,62-0,68 cm. Total 72 spesies dijumpai
hidup berdampingan dengan merbau di semua tingkatan pertumbuhan.
Pometia coreacea adalah salah satu dari jenis yang selalu dijumpai pada tiga lokasi
penelitian dengan nilai Chi-square tertinggi (X2 =2,00). Nilai indeks
biodiversitas jenis pendamping (kekayaan, kesamaan, keanekaragaman dan
kemerataan) mengindikasikan suatu komunitas pendukung yang stabil dengan
tingkat kekayaan dan kemerataan yang tinggi. Di persemaian in situ, tinggi bibit tertinggi 43,08 cm pada
naungan rapat, diameter dan jumlah daun pada naungan sedang yaitu 0,57 cm 28 helai. Benih merbau
terinfeksi patogen penyebab busuk benih (Fusarium spp.) dan hama (belalang
dan kutu putih) dijumpai menyerang daun dan pucuk bibit dengan kriteria
ringan-sehat. Nilai ordinansi bibit merbau sehat
berkualitas di persemaian in situ, mencapai kategori berkualitas
(63,32%) pada naungan rapat. Sedangkan
berdasarkan nilai leverage, yang perlu diprioritaskan adalah intensitas
serangan hama intensitas serangan penyakit, indeks kekokohan, dan frekuensi
serangan penyakit Nilai ordinansi bibit merbau sehat adaptif ditunjukkan
dengan nilai ordinasi kategori moderat di semua kondisi naungan dengan kisaran
48,40% - 52,84%. Sedangkan berdasarkan
nilai leverage prioritas yaitu intensitas serangan hama dan frekuensi
serangan penyakit. Pada persemaian ex
situ, di musim hujan dan kemarau benih merbau dapat bertumbuh dengan baik. Komponen pertumbuhan terbaik pada
musim hujan berturut-turut tinggi 46,44 cm pada naungan rapat, diameter dan
jumlah daun yaitu 0,57 cm dan 23 helai
pada naungan sedang. Sedangkan di musim kemarau tinggi 38,54,
diameter 0,62 cm dan jumlah daun 36
helai yang kesemuanya dihasilkan pada
naungan sedang. Komposisi nutrisi media tanam pada kedua musim berada pada kategori sangat
rendah-sangat tinggi. Patogen
busuk benih Fusarium
sp., Aspergillus spp., dan hama belalang, kutu putih dijumpai menyerang daun dan pucuk, dengan kriteria ringan-sehat. Nilai
ordinansi bibit merbau sehat berkualitas di persemaian ex situ pada
musim hujan dan kemarau berturut-turut adalah kategori berkualitas 70,93%
(naungan jarang) dan 62,87% (naungan sedang). Sedangkan nilai leverage prioritas
adalah unsur hara makro bibit, intensitas serangan hama, unsur hara mikro serta
jumlah daun. Nilai ordinansi bibit merbau sehat adaptif pada kedua musim
berturut-turut adalah kategori berkualitas 64,36% (naungan jarang) dan moderat
47,73% - 59,49% (semua naungan). Sedangkan nilai leverage prioritas adalah intensitas
serangan hama dan penyakit, unsur hara makro dan mikro media tanam. Bibit
merbau sehat berkualitas dihasilkan dengan kategori berkualitas dimusim hujan
dengan 5 faktor yang berpengaruh, sedangkan bibit merbau sehat adaptif kategori
moderat di semua musim dengan 4 faktor yang saling berpengaruh. Konservasi circa situm
berpeluang diterapkan guna memaksimalkan peran masyarakat adat dalam
pengelolaan hasil antara dari jenis merbau sebelum hasil kayu.
Kata kunci: Intsia bijuga, persemaian in
situ – ex situ, bibit sehat berkualitas, bibit sehat adaptif,
konservasi in situ, konservasi circa situm, konservasi ex situ
Merbau
(Intsia bijuga Colebr O. Kuntze) is an endemic species that is becoming
rare and requires concrete efforts to minimize overexploitation. One of the
efforts being made is to conserve this species outside its original habitat.
Research was conducted in two places, namely the natural habitat of merbau (in
situ) and outside its original habitat (ex situ). The natural
habitat of merbau is forest area of the Gunung Meja Nature Tourism Park in
Manokwari district and the Bembab forest area in South Manokwari district. The
habitat outside its original habitat is the Manokwari nursery (Forestry
Training Center) representing the transitional season and the Faculty of
Forestry UGM nursery in Yogyakarta representing the rainy and dry seasons. The
research was carried out for 6 month. The study aims to assess the performance
of merbau (soil quality, productivity, biodiversity, and health) in its natural
habitat/in situ, to determine the growth and development of merbau seedlings
generatively (in situ-ex situ) as a reference for developing
assessment tools for healthy, high-quality, and adaptive merbau seedlings, and
to determine the prospect of the tool for assessing healthy, high-quality, and
adaptive merbau seedlings in support of productive conservation in situ-ex
situ. Analysis of soil quality, productivity, biodiversity index, and health
quality was carried out to assess the performance of merbau in its natural
distribution. Analysis of growing media, one
and two way ANOVA analysis on the effect of shade and the interaction of season
and shade on the growth components of seedlings in the in situ-ex situ nursery, disturbance to seedlings (pests
and diseases), determination of healthy, high-quality, and adaptive merbau
seedlings with MultiDimensional Scalling, and analysis of the prospect of the
tool. The results showed that merbau can grow well in areas with soil quality
components ranging from low to very high. The highest productivity of merbau
stands was observed in the TWAGM area with an LBDS value of 0.35 m2, volume of
4.91 m3 at a diameter class of 0.62-0.68 cm. A total of 72 species were found
living alongside merbau at all growth levels. Pometia coreacea is one of
the species always found in all three research locations with the highest
Chi-square value (X2 = 2.00). The biodiversity index value of
companion species (richness, similarity, diversity, and evenness) indicates a
stable supporting community with high richness and evenness levels. The growth components of seedlings in
the in situ nursery had heighest of 43.04 cm in dense shade, diameter and
number of leaves in medium shade was 0.57 cm and 28 pieces. Merbau seeds
were infected with seed rot pathogenic fungi (Fusarium spp.), and pests
(grasshoppers and whiteflies) were found to attack the leaves and shoots of
seedlings with mild-healthy criteria. The ordination value of healthy,
high-quality merbau seedlings in the in situ nursery reached the high-quality
category (63.32%) in dense shade. Based on the value of leverage, the priority
should be given to the intensity of pest attacks, intensity of disease attacks,
resilience index, and frequency of disease attacks. The adaptive healthy merbau
seedlings are indicated by a moderate category of ordination values in all
shade conditions, ranging from 48.40% - 52.84%. Meanwhile, based on the value
of leverage, the priority is given to the intensity of pest attacks and
frequency of disease attacks. In ex-situ nurseries, merbau seeds can grow well
in both rainy and dry seasons. The best growth components in the rainy season
were a height of 46.44 cm in dense shade, a diameter and number of leaves of
0.57 cm and 23 leaves in moderate shade. Meanwhile, in the dry season the
height is 38.54, the diameter is 0.62 cm and the number of leaves is 36, all of
which are produced in moderate shade.The nutrient composition of the growing
media in both seasons is categorized as very low to very high. Seed rot
pathogens, such as Fusarium sp. and Aspergillus spp., and pests
such as grasshoppers and whiteflies, are found attacking the leaves and shoots,
with mild to healthy criteria. The value of healthy merbau seedlings in
high-quality nurseries in the rainy and dry seasons, respectively, are
categorized as 70.93% (sparse shade) and 62.87% (moderate shade). Meanwhile,
the priority value is given to macro-nutrient elements of the seedlings,
intensity of pest attacks, micro-nutrient elements, and number of leaves. The
value of adaptive healthy merbau seedlings in both seasons, respectively, are
categorized as high quality 64.36% (sparse shade) and moderate 47.73% - 59.49%
(all shades). Meanwhile, the priority value is given to the intensity of pest
and disease attacks, macro and micro-nutrient elements of the growing media.
High-quality healthy merbau seedlings are produced in the rainy season with
five influential factors, while moderately adaptive healthy merbau seedlings
are produced in all seasons with four interrelated factors. Conservation of the
circa situm has the potential to be applied to maximize the role of indigenous
communities in managing the intercrop yields of merbau species, before timber products.
Kata Kunci : Keywords: Intsia bijuga, in situ - ex situ nursery, high quality healthy seedlings, adaptive healthy seedlings, in situ conservation, circa situm conservation, ex situ conservation.
