Indicator: LD-03 Change in extent and proportion of woody vegetation, clearing and regrowth

Data

Changes in "forest" extent

"Forest" for the purposes of this analysis is vegetation (including both native and non-native vegetation), that grows at least 2 metres high with 20% canopy. Data from the AGO’s National Carbon Accounting System's Land Cover Change Project (from remote sensing) have been used to give a detailed picture of the extent and changes in extent of forest across Australia. Images received at intervals ranging from one to five years are compared and the change in vegetation cover mapped and converted into data on area.

The data have also been manipulated to show wooded land cleared and revegetated between the points in time at which forest extent was measured. Prior to supplying the data, AGO applied masks to exclude any loss of extent that is not due to land use change. The clearing and regrowth data therefore exclude clearing as result of fire or forestry (where the land use has not changed). This means that the forest extent data and the clearing and regrowth data are not strictly comparable.

In 1972, satellite imagery showed about 114 million hectares of forest across Australia. Between 1972 an 2004, there has been a net loss of around 8.4 million hectares of forest, despite net gains in NSW, NT and the ACT. Across the continent, about 106 million hectares of forest remained in 2004.

The following summary of the data has been compiled. The summary includes changes in extent since 1972, the loss or gain in extent between these points in time, the average annual loss or gain for each of these periods, and a summary of these data for three key periods: 1972 to 2000, 1972 to 2004 and 2000 to 2004.

Over the four decades, or part decades, over which the satellite images have been received (the 1970s, 1980s, 1990s and 2000s), as close as the image intervals allow these to be analysed, all decades except the 1990s (1989 - 2000) saw a net loss in forest extent from that present at the end of the preceding decade. The loss in the 1970s (1972-1980) was more than double the loss in the 1980s. The net gain in the 1990s was about 44 thousand hectares. However, the loss during the first four years of the 2000s is approaching the same figures as the loss in the nine years of the 1980s (1980-1989). The average annual loss of forest extent, continent-wide, between 2000 and 2004 is greater (by 3000-4000 hectares a year) than the average annual loss of vegetation between 1972 and 2000.

Analysis of changes in extent of forest

Extent (hectares) of woody vegetation by year by State
STATE	1972	1977	1980	1985	1988	1989	1991	1992	1995	1998	2000	2002	2004
ACT	138,900	133,000	134,100	135,200	137,800	141,600	142,800	143,800	147,100	147,600	150,500	151,900	145,500
NSW	19,492,500	18,818,900	18,956,700	19,044,900	19,155,800	19,525,400	19,676,900	19,835,900	20,133,400	20,095,500	19,958,400	19,938,700	20,089,400
NT	8,158,000	8,185,600	8,301,600	8,345,400	8,274,800	8,114,800	8,280,400	8,328,400	8,318,100	8,491,700	8,562,700	8,593,700	8,839,100
QLD	46,567,200	44,856,200	44,318,000	42,885,700	42,172,300	42,138,000	42,167,200	42,164,100	42,012,700	41,807,600	42,461,200	41,679,100	41,633,100
SA	7,215,200	6,718,900	6,472,600	6,333,400	6,294,400	6,368,600	6,423,100	6,436,900	6,446,600	6,414,400	6,306,900	6,319,800	6,340,400
TAS	4,913,200	4,894,500	4,902,000	4,873,400	4,852,900	4,797,500	4,778,400	4,766,100	4,738,200	4,707,700	4,710,900	4,705,900	4,697,200
VIC	7,939,200	7,898,600	7,883,800	7,632,600	7,550,800	7,671,200	7,717,300	7,733,900	7,853,300	7,841,700	7,817,200	7,908,200	7,795,000
WA	19,526,900	18,397,500	17,612,900	16,893,400	16,939,900	17,046,600	16,752,200	16,575,900	16,329,400	16,568,600	16,693,700	16,622,800	16,065,000
Total	113,951,100	109,903,200	108,581,800	106,144,000	105,378,700	105,803,500	105,938,200	105,984,900	105,978,800	106,074,800	106,661,500	105,920,100	105,604,700

Source: Derived from AGO [Australian Greenhouse Office] 2006, Analysis of forest in Australia, unpublished data, Australian Greenhouse Office, Department of the Environment and Heritage. Source of data AGO Version 2, May 2006, NCAS, Department of the Environment and Heritage and the Australian Greenhouse Office, Canberra.

Extent (hectares) of woody vegetation by year by State

Loss or gain of forest extent (hectares) by year by State (negative figures represent a net gain)
STATE	1972-77	1977-80	1980-85	1985-88	1988-89	1989-91	1991-92	1992-95	1995-98	1998-00	2000-02	2002-04	1972-04	1972-00	2000-04
ACT	6,000	-1,100	-1,100	-2,600	-3,800	-1,200	-1,000	-3,000	-1,000	-3,000	-1,400	6,400	-6,500	-11,600	5,100
NSW	673,600	-137,800	-88,200	-110,900	-369,600	-151,500	-159,000	-297,500	37,900	137,100	19,800	-150,800	-597,000	-466,000	-131,000
NT	-27,600	-116,100	-43,700	70,600	160,000	-165,600	-48,000	10,200	-173,600	-71,000	-31,100	-245,300	-681,100	-404,700	-276,400
QLD	1,711,000	538,200	1,432,300	713,500	34,300	-29,200	3,200	151,300	205,200	-653,600	782,100	46,000	4,934,200	4,106,000	828,100
SA	496,300	246,200	139,300	38,900	-74,200	-54,500	-13,800	-9,600	32,200	107,500	-12,900	-20,700	874,700	908,300	-33,600
TAS	18,700	-7,400	28,500	20,500	55,400	19,000	12,400	27,900	30,500	-3,200	5,000	8,700	216,000	202,300	13,700
VIC	40,600	14,800	251,200	81,800	-120,300	-46,100	-16,700	-119,400	11,600	24,500	-91,000	113,200	144,300	122,000	22,300
WA	1,129,300	784,700	719,500	-46,500	-106,800	294,500	176,300	246,500	-239,100	-125,100	70,800	557,800	3,461,900	2,833,200	628,700
Total	4,047,800	1,321,500	2,437,700	765,400	-424,900	-134,700	-46,700	6,000	-95,900	-586,700	741,400	315,400	8,346,400	7,289,600	1,056,900

Loss or gain of forest extent (hectares) by year by State (negative figures represent a net gain)

Average annual loss or gain (hectares) of forest extent by State for periods (negative figures represent a net gain)
STATE	1972-77	1977-80	1980-85	1985-88	1988-89	1989-91	1991-92	1992-95	1995-98	1998-00	2000-02	2002-04
ACT	1000	-300	-200	-700	-1,900	-300	-500	-800	-100	-1000	-300	2,200
NSW	112,300	-34,500	-14,700	-27,700	-184,800	-37,900	-79,500	-74,400	9,500	45,700	4,000	-50,300
NT	-4,600	-29,000	-7,300	17,700	80,000	-41,400	-24,000	2,600	-43,400	-23,700	-6,200	-81,800
QLD	285,200	134,500	238,700	178,400	17,100	-7,300	1,600	37,800	51,300	-217,900	156,400	15,300
SA	82,700	61,600	23,200	9,700	-37,100	-13,600	-6,900	-2,400	8,000	35,800	-2,600	-6,900
TAS	3,100	-1,900	4,800	5,100	27,700	4,800	6,200	7,000	7,600	-1,100	1,000	2,900
VIC	6,800	3,700	41,900	20,500	-60,200	-11,500	-8,300	-29,800	2,900	8,200	-18,200	37,800
WA	188,200	196,200	119,900	-11,600	-53,400	73,600	88,100	61,600	-59,800	-41,700	14,200	186,000
Total	674,600	330,400	406,300	191,300	-212,400	-33,700	-23,300	1,500	-24,000	-195,600	148,300	105,200

Average annual loss or gain (hectares) of forest extent by State for periods (negative figures represent a net gain)

Average annual loss or gain (hectares) of forest for various cumulative periods (negative figures represent a net gain)
	1972-1980	1980-1989	1989-2000	2000-2004	1972-2000	1972-2004
ACT	600	-900	-400	1,300	-400	-200
NSW	67,000	-63,200	-29,200	-32,800	-16,600	-18,700
NT	-18,000	20,800	-4,500	-69,100	-14,500	-21,300
QLD	281,200	242,200	-10,700	207,000	146,600	154,200
SA	92,800	11,600	-1,500	-8,400	32,400	27,300
TAS	1,400	11,600	4,700	3,400	7,200	6,800
VIC	6,900	23,600	-9,000	5,600	4,400	4,500
WA	239,300	62,900	6,200	157,200	101,200	108,200
Total	671,200	308,700	-44,300	264,200	260,300	260,800

Average annual loss or gain (hectares) of forest for various cumulative periods (negative figures represent a net gain)

Summary of extent, loss and average annual loss of forest at 1972, 2000 and 2004 (negative figures represent a net gain)
STATE	Extent by state 1972	Extent by state 2000	Extent by state 2004	Loss 72-04	Loss 72-00	Loss 00-04	Average annual loss 72-04	Average annual loss 72-00	Average annual loss 00-04
ACT	138,900	150,500	145,500	-11,600	-6,600	5,000	-400	-200	1,300
NSW	19,492,500	19,958,400	20,089,400	-465,900	-596,900	-131,000	-16,600	-18,700	-32,800
NT	8,158,000	8,562,700	8,839,100	-404,700	-681,100	-276,400	-14,500	-21,300	-69,100
QLD	46,567,200	42,461,200	41,633,100	4,106,000	4,934,100	828,100	146,600	154,200	207,000
SA	7,215,200	6,306,900	6,340,400	908,300	874,800	-33,500	32,400	27,300	-8,400
TAS	4,913,200	4,710,900	4,697,200	202,300	216,000	13,700	7,200	6,800	3,400
VIC	7,939,200	7,817,200	7,795,000	122,000	144,200	22,200	4,400	4,500	5,600
WA	19,526,900	16,693,700	16,065,000	2,833,200	3,461,900	628,700	101,200	108,200	157,200
Total	113,951,100	106,661,500	105,604,700	7,289,600	8,346,400	1,056,800	260,300	260,800	264,200

The following map shows various percentages of forest remaining by IBRA region.

Percentage of forest remaining by IBRA region

Clearing and regrowth

Over 17 million ha of woody vegetation were cleared continent-wide between 1972 and 2004. Of this, one and a half million hectares were cleared between 2000 and 2004. The area revegetated between 1972 and 2004 was 9.4 million ha. This leaves a net area cleared between 1972 and 2004 of 7.6 million hectares.

Area of woody vegetation cleared in Australia, 1973-2004, by hectares* (may include land that has been cleared more than once during the period)
Year	1973	1974	1975	1976	1977	1978	1979	1980
Clearing	652 700	1054600	957 400	577 100	444 400	456 000	463 200	671 700
Regrowth	351,700	549,200	478,800	248,400	160,600	154,900	157,300	245,800
Net loss	301,100	505,400	478,600	328,700	283,900	301,200	305,900	425,800
Year	1981	1982	1983	1984	1985	1986	1987	1988
Clearing	708 200	707 300	707 700	671 100	503 500	500 200	507 300	557 300
Regrowth	257,100	256,800	257,100	256,700	250,400	253,100	253,100	350,200
Net loss	451,000	450,500	450,600	414,500	253,100	247,100	254,200	207,100
Year	1989	1990	1991	1992	1993	1994	1995	1996
Clearing	572 700	623 000	483 000	447 700	454 900	431 000	373 000	376 400
Regrowth	391,700	464,010	395,700	331,300	318,600	304,900	228,400	223,400
Net loss	181,000	159,000	86,800	116,400	136,300	126,100	144,500	153,000
Year	1997	1998	1999	2000	2001	2002	2003	2004
Clearing	372 300	397 600	403 800	418 600	419 600	347 300	327 400	424 700
Regrowth	222,300	233,957	240,046	294,493	302,389	317,394	311,124	371,195
Net loss	150,000	163,700	163,700	124,100	117,200	29,900	16,300	53,500
*All figures have been rounded to the nearest 100 hectares

The chart below shows these data graphically.

Area of woody vegetation cleared in Australia, 1973-2004, by hectares* (may include land that has been cleared more than once during the period)

Between 2000 and 2001, all states except Queensland showed regrowth outstripping clearing, but the clearing rate in Queensland overwhelmed the net gains in other jurisdictions.

Area of woody vegetation (hectares)* cleared in states and territories, 2001-2004 (may include land that has been cleared more than once during the period)
State/Territory	2001 (ha)	2002 (ha)	2003 (ha)	2004 (ha)
NSW	72 400	64 100	64 100	110 900
NT	1 300	1 500	1 700	5 800
Qld	288 300	215 100	192 400	220 000
SA	9 900	8 400	8 100	12 300
Tas	7 400	10 400	12 300	13 700
Vic	10 500	13 100	13 600	23 400
WA	29 800	34 600	35 200	38 700
Total	419 600	347 200	327 400	424 700
*All figures have been rounded to the nearest 100 hectares

The chart below shows these data graphically.

Area of woody vegetation (hectares)* cleared in states and territories, 2001-2004 (may include land that has been cleared more than once during the period)

Area of woody vegetation regrowth (hectares)* in states and territories, 2001-2004 (may include land that has been cleared more than once during the period)
State	2001	2002	2003	2004
NSW	63 600	74 900	76 500	115 300
NT	4 200	5 300	6 300	9 100
Qld	99 800	115 400	108 300	117 200
SA	18 500	15 500	15 400	18 600
Tas	12 800	12 500	12 500	11 400
Vic	40 300	36 800	35 500	49 300
WA	63 200	57 100	56 500	50 300
TOTAL	302 400	317 500	311 000	371 200
*All figures have been rounded to the nearest 100 hectares

The chart below shows these data graphically.

Area of woody vegetation regrowth (hectares)* in states and territories, 2001-2004 (may include land that has been cleared more than once during the period)

Net change by state 2001-2004 (negative values indicate a net loss)
	2001	2002	2003	2004
NSW	-8,800	10,800	12,400	4,500
NT	2,900	3,800	4,600	3,300
QLD	-188,400	-99,800	-84,100	-102,800
SA	8,500	7,100	7,400	6,300
TAS	5,400	2,100	300	-2,300
Vic	29,800	23,800	21,900	25,900
WA	33,400	22,500	21,300	11,500

The chart below shows these changes graphically

Net change by state 2001-2004 (negative values indicate a net loss)

Cumulative total 2001-2004 (negative values indicate a net loss)
	Clearing	Regrowth	Net gain
NSW	311,400	330,300	18,900
NT	10,300	24,900	14,600
QLD	915,700	440,700	-475,000
SA	38,800	68,000	29,300
TAS	43,800	49,200	5,400
Vic	60,600	162,000	101,400
WA	138,300	227,000	88,700
Australia	1,518,900	1,302,100	-216,800
*All figures have been rounded to the nearest 100 hectares

The following two maps show percentages of IBRA regions cleared of forest between 1980 and 2002, and percentages of IBRA regions where forest has regrown during the same period.

Percentage of IBRA regions cleared of forest between 1980 and 2002

Percentage of IBRA regions where forest has regrown during 1980 and 2002

What the data mean

The data show that, while considerable revegetation has taken place in the last 24 years, a substantial net loss of vegetation is still occurring.

Land clearing continues in all States and Territories and especially in Queensland. Almost 220 000 hectares of woody vegetation was cleared in Queensland in 2004.

Revegetation programs and natural regrowth in Australia have had a positive effect but at no time since 1973 has woody regrowth exceeded clearing of woody vegetation, mainly due to the high clearing rates in Queensland. Over the four year period 2001-2004 Queensland cleared 915 000 hectares of woody vegetation while only 440 700 hectares grew back. In all other states and territories, except for Tasmania, regrowth exceeded clearing in 2004.

Data Limitations

The data show changes in extent of forest cover, but provide no insights into the type of woody vegetation or the condition of that vegetation. They also provide no information about changes in the extent of non-woody vegetation (grasslands, low shrubs etc) which together originally covered about 40% of the continent (see Indicator LD-01 The proportion and area of native vegetation and changes over time ).

It is especially important to note that regrowth of vegetation does not imply regrowth of the original species of vegetation nor guarantee the restoration of the original ecosystem, as many plants and animals may not be available to recolonise the cleared area.

All data are assumed correct at the time of supply. This data was provided to the Department of the Environment and Heritage (DEH) by the AGO and was the best available information at the time. All subsequent analysis by DEH assumes data are correct as received from the supplier. This is an 'Indicative Analysis Only' with a focus on monitoring trends through time. For this reason all results to have been rounded to the nearest 100 ha.

Issues for which this is an indicator and why

Biodiversity - Pressures on biodiversity - Land clearing

Woody vegetation is generally perennial and deep-rooted, providing year-round habitat for other biota and protecting soil, micro-climate, groundwater and water catchments. It is woody vegetation that has seen the most significant reductions since the European invasion. Extent and change in extent, clearing and regrowth of woody vegetative is a direct indicator of the pressure of land clearing on biodiversity.